A Peek Inside the [pb_glossary id=\"5665\"]Cell[\/pb_glossary]<\/h1>\r\n<\/div>\r\nFigure 4.5.1 is an artist's representation of what you might see if you could take a peek inside one of these basic building blocks of living things.\u00a0 <\/span>A\u00a0cell's interior is obviously a crowded and busy space. It contains cytoplasm, dissolved substances, and many structures. It's a hive of countless biochemical activities all going on at once.\u00a0<\/span>\r\n\r\nCytoplasm<\/h1>\r\n<\/div>\r\n[pb_glossary id=\"5465\"]Cytoplasm[\/pb_glossary] is a thick, usually colourless solution that fills each cell and is enclosed by the [pb_glossary id=\"5621\"]cell membrane[\/pb_glossary]. Cytoplasm presses against the cell membrane, filling out the cell and giving it its shape. Sometimes, cytoplasm acts like a watery solution, and sometimes, it takes on a more gel-like consistency. In [pb_glossary id=\"1573\"]eukaryotic[\/pb_glossary] cells, the cytoplasm includes all of the material inside the [pb_glossary id=\"5665\"]cell[\/pb_glossary] but outside of the [pb_glossary id=\"5797\"]nucleus[\/pb_glossary], which contains its own watery substance called the [pb_glossary id=\"5569\"]nucleoplasm[\/pb_glossary]. All of the organelles in eukaryotic cells (such as the endoplasmic reticulum and mitochondria) are located in the cytoplasm. The cytoplasm helps to keep them in place. It is also the site of most metabolic activities in the cell, and it allows materials to pass easily throughout the cell.\r\n\r\nThe portion of the cytoplasm surrounding\u00a0[pb_glossary id=\"5557\"]organelles[\/pb_glossary]\u00a0is called\u00a0[pb_glossary id=\"5737\"]cytosol[\/pb_glossary]<\/strong>. Cytosol is the liquid part of cytoplasm. It is composed of about 80 per cent water, and it contains dissolved salts, [pb_glossary id=\"5657\"]fatty acids[\/pb_glossary], [pb_glossary id=\"316\"]sugars[\/pb_glossary], [pb_glossary id=\"5707\"]amino acids[\/pb_glossary], and [pb_glossary id=\"5813\"]proteins[\/pb_glossary] (such as enzymes). These dissolved substances are needed to keep the cell alive and carry out metabolic processes. [pb_glossary id=\"5757\"]Enzymes[\/pb_glossary] dissolved in cytosol, for example, break down larger molecules into smaller products that can then be used by organelles of the cell. Waste products are also dissolved in the cytosol before they are taken in by vacuoles or expelled from the cell.\r\n\r\n\r\n[caption id=\"attachment_1610\" align=\"alignright\" width=\"465\"]![\"The](\"https:\/\/pressbooks.ccconline.org\/acchumanbio\/wp-content\/uploads\/sites\/152\/2023\/10\/Cytoskeleton-2.jpg\")
Figure 4.5.2 The cytoskeleton gives the cell an internal structure, like the frame of a house. In this photograph, filaments and tubules of the cytoskeleton have been stained green and red, respectively, so that they can be seen clearly. The blue dots are cell nuclei.<\/em>[\/caption]\r\nCytoskeleton<\/h1>\r\n<\/div>\r\nAlthough cytoplasm may appear to have no form or structure, it is actually highly organized. A framework of\u00a0protein\u00a0scaffolds called the\u00a0[pb_glossary id=\"5735\"]cytoskeleton[\/pb_glossary]<\/strong> provides the [pb_glossary id=\"5465\"]cytoplasm[\/pb_glossary] and the cell with structure. The cytoskeleton consists of thread-like microfilaments, intermediate filaments, and microtubules that criss-cross the cytoplasm. You can see these filaments and tubules in the cells in Figure 4.5.2. As its name suggests, the cytoskeleton is like a cellular \u201cskeleton.\u201d It helps the cell maintain its shape and also helps to hold cell structures (like organelles) in place within the cytoplasm.\r\n\r\n\r\n \r\n\r\n<\/div>\r\n\r\nFeature: Human Biology in the News<\/h1>\r\n<\/div>\r\nNews about an important study of the cytoplasm of eukaryotic\u00a0cells\u00a0came out in early 2016. Researchers in Dresden, Germany discovered that when cells are deprived of adequate\u00a0nutrients, they may essentially shut down and become dormant. Specifically, when cells do not get enough nutrients, they shut down their metabolism, their\u00a0energy level\u00a0drops, and the\u00a0pH\u00a0of their cytoplasm decreases. Their normally\u00a0liquid\u00a0cytoplasm also assumes a\u00a0solid\u00a0state. The cells appear dead, as though a kind of rigor mortis has set in. The researchers think that these changes protect the sensitive structures inside the cells and allow the cells to survive difficult conditions. If nutrients are returned to the cells, they can emerge from their dormant state unharmed. They will continue to grow and multiply when conditions improve.\r\n\r\nThis important basic science\u00a0research\u00a0was\u00a0executed\u00a0on a nonhuman organism: one-celled\u00a0fungi\u00a0called yeasts. Nonetheless, it may have important implications for humans, because yeasts have eukaryotic cells with many of the same structures as human cells. Yeast cells appear to be able to \"trick\" death by shutting down all life processes in a controlled way. Through continued study, researchers hope to learn whether human cells can be taught this \"trick\" as well.\r\n\r\n4.5 Summary<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\n \t- [pb_glossary id=\"5465\"]Cytoplasm[\/pb_glossary] is a thick\u00a0solution\u00a0that fills a [pb_glossary id=\"5665\"]cell [\/pb_glossary]and is enclosed by the\u00a0[pb_glossary id=\"5621\"]cell membrane[\/pb_glossary]. It has many functions. It helps give the cell shape, holds organelles, and provides a site for many of the\u00a0biochemical reactions inside the cell.<\/li>\r\n \t
- The\u00a0liquid\u00a0part of the cytoplasm is called cytosol. It is mainly\u00a0water, and it contains many dissolved substances. The cytoplasm of a eukaryotic cell also contains a membrane-enclosed\u00a0nucleus\u00a0and other organelles.<\/li>\r\n \t
- The cytoskeleton is a highly organized framework of\u00a0protein\u00a0filaments and tubules that criss-cross the cytoplasm of a cell. It gives the\u00a0cell structure\u00a0and helps hold cell structures (such as [pb_glossary id=\"5557\"]organelles[\/pb_glossary]) in place within the cytoplasm.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n
\r\n4.5 Review Questions<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\n \t- Describe the composition of cytoplasm.\u00a0 Draw a picture of a cell, including the basic components required to be considered a cell, and the organelles you have learned about in this section.<\/li>\r\n \t
- What are some of the functions of cytoplasm?<\/li>\r\n \t
- Outline the structure and functions of the cytoskeleton.<\/li>\r\n \t
- Is the cytoplasm made of cells? Why or why not?<\/li>\r\n \t
- Name two types of cytoskeletal structures.<\/li>\r\n \t
- In the picture of the different cytoskeletal structures above (Figure 4.5.2), what do you notice about these different structures?<\/li>\r\n \t
- Describe one example of a metabolic process that\u00a0happens\u00a0in the cytosol.<\/li>\r\n \t
- In eukaryotic cells, all of the material inside of the cell, but\u00a0outside of the nucleus is called the ___________ .<\/li>\r\n \t
- What is the liquid part of cytoplasm called?<\/li>\r\n \t
- What chemical substance\u00a0composes\u00a0most of the cytosol?<\/li>\r\n \t
- When yeast cells deprived of\u00a0nutrients go dormant, their cytoplasm assumes a\u00a0solid state. What effect do you think a solid cytoplasm would have on normal cellular processes? Explain your answer.<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n
\r\n4.5 Explore More<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\nhttps:\/\/www.youtube.com\/watch?v=YTv9ItGd050\r\nCytoskeleton Structure and Function, National Center for Case Study\r\nTeaching in Science, 2015.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n
Attributions<\/h2>\r\nFigure 4.5.1<\/strong>\r\n\r\nCell-organelles-labeled<\/a> by Koswac<\/a> on Wikimedia Commons is used under a CC BY-SA 4.0<\/a> (https:\/\/creativecommons.org\/licenses\/by-sa\/4.0) license.\r\n\r\nFigure 4.5.2<\/strong>\r\n\r\n\r\n\r\n\r\nCytoskeleton\/ Fluorescent Cells<\/a> by National Institute of Health (NIH)<\/a> on Wikimedia Commons is released into the public domain <\/a>(https:\/\/en.wikipedia.org\/wiki\/Public_domain).\r\n\r\n \r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\nReferences<\/span><\/div>\r\n<\/section>\r\nNational Center for Case Study Teaching in Science. (2015, August 3). Cytoskeleton structure and function. YouTube. https:\/\/www.youtube.com\/watch?v=YTv9ItGd050&feature=youtu.be<\/p>","rendered":"
<\/p>\n![\"Image](\"https:\/\/pressbooks.ccconline.org\/acchumanbio\/wp-content\/uploads\/sites\/152\/2019\/06\/Cell-organelles-labeled-2.png\")
Figure 4.5.1 The cytoplasm is filled with many organelles, each doing their own specific jobs.<\/em><\/figcaption><\/figure>\n\nA Peek Inside the Cell<\/a><\/h1>\n<\/div>\nFigure 4.5.1 is an artist’s representation of what you might see if you could take a peek inside one of these basic building blocks of living things.\u00a0 <\/span>A\u00a0cell’s interior is obviously a crowded and busy space. It contains cytoplasm, dissolved substances, and many structures. It’s a hive of countless biochemical activities all going on at once.\u00a0<\/span><\/p>\n\nCytoplasm<\/h1>\n<\/div>\n
Cytoplasm<\/a> is a thick, usually colourless solution that fills each cell and is enclosed by the cell membrane<\/a>. Cytoplasm presses against the cell membrane, filling out the cell and giving it its shape. Sometimes, cytoplasm acts like a watery solution, and sometimes, it takes on a more gel-like consistency. In eukaryotic<\/a> cells, the cytoplasm includes all of the material inside the cell<\/a> but outside of the nucleus<\/a>, which contains its own watery substance called the nucleoplasm<\/a>. All of the organelles in eukaryotic cells (such as the endoplasmic reticulum and mitochondria) are located in the cytoplasm. The cytoplasm helps to keep them in place. It is also the site of most metabolic activities in the cell, and it allows materials to pass easily throughout the cell.<\/p>\nThe portion of the cytoplasm surrounding\u00a0organelles<\/a>\u00a0is called\u00a0cytosol<\/a><\/strong>. Cytosol is the liquid part of cytoplasm. It is composed of about 80 per cent water, and it contains dissolved salts, fatty acids<\/a>, sugars<\/a>, amino acids<\/a>, and proteins<\/a> (such as enzymes). These dissolved substances are needed to keep the cell alive and carry out metabolic processes. Enzymes<\/a> dissolved in cytosol, for example, break down larger molecules into smaller products that can then be used by organelles of the cell. Waste products are also dissolved in the cytosol before they are taken in by vacuoles or expelled from the cell.<\/p>\n\nFigure 4.5.2 The cytoskeleton gives the cell an internal structure, like the frame of a house. In this photograph, filaments and tubules of the cytoskeleton have been stained green and red, respectively, so that they can be seen clearly. The blue dots are cell nuclei.<\/em><\/figcaption><\/figure>\nCytoskeleton<\/h1>\n<\/div>\n
Although cytoplasm may appear to have no form or structure, it is actually highly organized. A framework of\u00a0protein\u00a0scaffolds called the\u00a0cytoskeleton<\/a><\/strong> provides the cytoplasm<\/a> and the cell with structure. The cytoskeleton consists of thread-like microfilaments, intermediate filaments, and microtubules that criss-cross the cytoplasm. You can see these filaments and tubules in the cells in Figure 4.5.2. As its name suggests, the cytoskeleton is like a cellular \u201cskeleton.\u201d It helps the cell maintain its shape and also helps to hold cell structures (like organelles) in place within the cytoplasm.<\/p>\n\n <\/p>\n<\/div>\n
\nFeature: Human Biology in the News<\/h1>\n<\/div>\n
News about an important study of the cytoplasm of eukaryotic\u00a0cells\u00a0came out in early 2016. Researchers in Dresden, Germany discovered that when cells are deprived of adequate\u00a0nutrients, they may essentially shut down and become dormant. Specifically, when cells do not get enough nutrients, they shut down their metabolism, their\u00a0energy level\u00a0drops, and the\u00a0pH\u00a0of their cytoplasm decreases. Their normally\u00a0liquid\u00a0cytoplasm also assumes a\u00a0solid\u00a0state. The cells appear dead, as though a kind of rigor mortis has set in. The researchers think that these changes protect the sensitive structures inside the cells and allow the cells to survive difficult conditions. If nutrients are returned to the cells, they can emerge from their dormant state unharmed. They will continue to grow and multiply when conditions improve.<\/p>\n
This important basic science\u00a0research\u00a0was\u00a0executed\u00a0on a nonhuman organism: one-celled\u00a0fungi\u00a0called yeasts. Nonetheless, it may have important implications for humans, because yeasts have eukaryotic cells with many of the same structures as human cells. Yeast cells appear to be able to “trick” death by shutting down all life processes in a controlled way. Through continued study, researchers hope to learn whether human cells can be taught this “trick” as well.<\/p>\n
\n\n4.5 Summary<\/span><\/h1>\n<\/header>\n\n\n- Cytoplasm<\/a> is a thick\u00a0solution\u00a0that fills a cell <\/a>and is enclosed by the\u00a0cell membrane<\/a>. It has many functions. It helps give the cell shape, holds organelles, and provides a site for many of the\u00a0biochemical reactions inside the cell.<\/li>\n
- The\u00a0liquid\u00a0part of the cytoplasm is called cytosol. It is mainly\u00a0water, and it contains many dissolved substances. The cytoplasm of a eukaryotic cell also contains a membrane-enclosed\u00a0nucleus\u00a0and other organelles.<\/li>\n
- The cytoskeleton is a highly organized framework of\u00a0protein\u00a0filaments and tubules that criss-cross the cytoplasm of a cell. It gives the\u00a0cell structure\u00a0and helps hold cell structures (such as organelles<\/a>) in place within the cytoplasm.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n\n
\n4.5 Review Questions<\/span><\/h1>\n<\/header>\n\n\n- Describe the composition of cytoplasm.\u00a0 Draw a picture of a cell, including the basic components required to be considered a cell, and the organelles you have learned about in this section.<\/li>\n
- What are some of the functions of cytoplasm?<\/li>\n
- Outline the structure and functions of the cytoskeleton.<\/li>\n
- Is the cytoplasm made of cells? Why or why not?<\/li>\n
- Name two types of cytoskeletal structures.<\/li>\n
- In the picture of the different cytoskeletal structures above (Figure 4.5.2), what do you notice about these different structures?<\/li>\n
- Describe one example of a metabolic process that\u00a0happens\u00a0in the cytosol.<\/li>\n
- In eukaryotic cells, all of the material inside of the cell, but\u00a0outside of the nucleus is called the ___________ .<\/li>\n
- What is the liquid part of cytoplasm called?<\/li>\n
- What chemical substance\u00a0composes\u00a0most of the cytosol?<\/li>\n
- When yeast cells deprived of\u00a0nutrients go dormant, their cytoplasm assumes a\u00a0solid state. What effect do you think a solid cytoplasm would have on normal cellular processes? Explain your answer.<\/li>\n<\/ol>\n<\/div>\n<\/div>\n\n
\n4.5 Explore More<\/span><\/h1>\n<\/header>\n\n
Cytoplasm<\/h1>\r\n<\/div>\r\n[pb_glossary id=\"5465\"]Cytoplasm[\/pb_glossary] is a thick, usually colourless solution that fills each cell and is enclosed by the [pb_glossary id=\"5621\"]cell membrane[\/pb_glossary]. Cytoplasm presses against the cell membrane, filling out the cell and giving it its shape. Sometimes, cytoplasm acts like a watery solution, and sometimes, it takes on a more gel-like consistency. In [pb_glossary id=\"1573\"]eukaryotic[\/pb_glossary] cells, the cytoplasm includes all of the material inside the [pb_glossary id=\"5665\"]cell[\/pb_glossary] but outside of the [pb_glossary id=\"5797\"]nucleus[\/pb_glossary], which contains its own watery substance called the [pb_glossary id=\"5569\"]nucleoplasm[\/pb_glossary]. All of the organelles in eukaryotic cells (such as the endoplasmic reticulum and mitochondria) are located in the cytoplasm. The cytoplasm helps to keep them in place. It is also the site of most metabolic activities in the cell, and it allows materials to pass easily throughout the cell.\r\n\r\nThe portion of the cytoplasm surrounding\u00a0[pb_glossary id=\"5557\"]organelles[\/pb_glossary]\u00a0is called\u00a0[pb_glossary id=\"5737\"]cytosol[\/pb_glossary]<\/strong>. Cytosol is the liquid part of cytoplasm. It is composed of about 80 per cent water, and it contains dissolved salts, [pb_glossary id=\"5657\"]fatty acids[\/pb_glossary], [pb_glossary id=\"316\"]sugars[\/pb_glossary], [pb_glossary id=\"5707\"]amino acids[\/pb_glossary], and [pb_glossary id=\"5813\"]proteins[\/pb_glossary] (such as enzymes). These dissolved substances are needed to keep the cell alive and carry out metabolic processes. [pb_glossary id=\"5757\"]Enzymes[\/pb_glossary] dissolved in cytosol, for example, break down larger molecules into smaller products that can then be used by organelles of the cell. Waste products are also dissolved in the cytosol before they are taken in by vacuoles or expelled from the cell.\r\n\r\n\r\n[caption id=\"attachment_1610\" align=\"alignright\" width=\"465\"] Figure 4.5.2 The cytoskeleton gives the cell an internal structure, like the frame of a house. In this photograph, filaments and tubules of the cytoskeleton have been stained green and red, respectively, so that they can be seen clearly. The blue dots are cell nuclei.<\/em>[\/caption]\r\nCytoskeleton<\/h1>\r\n<\/div>\r\nAlthough cytoplasm may appear to have no form or structure, it is actually highly organized. A framework of\u00a0protein\u00a0scaffolds called the\u00a0[pb_glossary id=\"5735\"]cytoskeleton[\/pb_glossary]<\/strong> provides the [pb_glossary id=\"5465\"]cytoplasm[\/pb_glossary] and the cell with structure. The cytoskeleton consists of thread-like microfilaments, intermediate filaments, and microtubules that criss-cross the cytoplasm. You can see these filaments and tubules in the cells in Figure 4.5.2. As its name suggests, the cytoskeleton is like a cellular \u201cskeleton.\u201d It helps the cell maintain its shape and also helps to hold cell structures (like organelles) in place within the cytoplasm.\r\n\r\n\r\n \r\n\r\n<\/div>\r\n\r\nFeature: Human Biology in the News<\/h1>\r\n<\/div>\r\nNews about an important study of the cytoplasm of eukaryotic\u00a0cells\u00a0came out in early 2016. Researchers in Dresden, Germany discovered that when cells are deprived of adequate\u00a0nutrients, they may essentially shut down and become dormant. Specifically, when cells do not get enough nutrients, they shut down their metabolism, their\u00a0energy level\u00a0drops, and the\u00a0pH\u00a0of their cytoplasm decreases. Their normally\u00a0liquid\u00a0cytoplasm also assumes a\u00a0solid\u00a0state. The cells appear dead, as though a kind of rigor mortis has set in. The researchers think that these changes protect the sensitive structures inside the cells and allow the cells to survive difficult conditions. If nutrients are returned to the cells, they can emerge from their dormant state unharmed. They will continue to grow and multiply when conditions improve.\r\n\r\nThis important basic science\u00a0research\u00a0was\u00a0executed\u00a0on a nonhuman organism: one-celled\u00a0fungi\u00a0called yeasts. Nonetheless, it may have important implications for humans, because yeasts have eukaryotic cells with many of the same structures as human cells. Yeast cells appear to be able to \"trick\" death by shutting down all life processes in a controlled way. Through continued study, researchers hope to learn whether human cells can be taught this \"trick\" as well.\r\n\r\n4.5 Summary<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\n \t- [pb_glossary id=\"5465\"]Cytoplasm[\/pb_glossary] is a thick\u00a0solution\u00a0that fills a [pb_glossary id=\"5665\"]cell [\/pb_glossary]and is enclosed by the\u00a0[pb_glossary id=\"5621\"]cell membrane[\/pb_glossary]. It has many functions. It helps give the cell shape, holds organelles, and provides a site for many of the\u00a0biochemical reactions inside the cell.<\/li>\r\n \t
- The\u00a0liquid\u00a0part of the cytoplasm is called cytosol. It is mainly\u00a0water, and it contains many dissolved substances. The cytoplasm of a eukaryotic cell also contains a membrane-enclosed\u00a0nucleus\u00a0and other organelles.<\/li>\r\n \t
- The cytoskeleton is a highly organized framework of\u00a0protein\u00a0filaments and tubules that criss-cross the cytoplasm of a cell. It gives the\u00a0cell structure\u00a0and helps hold cell structures (such as [pb_glossary id=\"5557\"]organelles[\/pb_glossary]) in place within the cytoplasm.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n
\r\n4.5 Review Questions<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\n \t- Describe the composition of cytoplasm.\u00a0 Draw a picture of a cell, including the basic components required to be considered a cell, and the organelles you have learned about in this section.<\/li>\r\n \t
- What are some of the functions of cytoplasm?<\/li>\r\n \t
- Outline the structure and functions of the cytoskeleton.<\/li>\r\n \t
- Is the cytoplasm made of cells? Why or why not?<\/li>\r\n \t
- Name two types of cytoskeletal structures.<\/li>\r\n \t
- In the picture of the different cytoskeletal structures above (Figure 4.5.2), what do you notice about these different structures?<\/li>\r\n \t
- Describe one example of a metabolic process that\u00a0happens\u00a0in the cytosol.<\/li>\r\n \t
- In eukaryotic cells, all of the material inside of the cell, but\u00a0outside of the nucleus is called the ___________ .<\/li>\r\n \t
- What is the liquid part of cytoplasm called?<\/li>\r\n \t
- What chemical substance\u00a0composes\u00a0most of the cytosol?<\/li>\r\n \t
- When yeast cells deprived of\u00a0nutrients go dormant, their cytoplasm assumes a\u00a0solid state. What effect do you think a solid cytoplasm would have on normal cellular processes? Explain your answer.<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n
\r\n4.5 Explore More<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\nhttps:\/\/www.youtube.com\/watch?v=YTv9ItGd050\r\nCytoskeleton Structure and Function, National Center for Case Study\r\nTeaching in Science, 2015.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n
Attributions<\/h2>\r\nFigure 4.5.1<\/strong>\r\n\r\nCell-organelles-labeled<\/a> by Koswac<\/a> on Wikimedia Commons is used under a CC BY-SA 4.0<\/a> (https:\/\/creativecommons.org\/licenses\/by-sa\/4.0) license.\r\n\r\nFigure 4.5.2<\/strong>\r\n\r\n\r\n\r\n\r\nCytoskeleton\/ Fluorescent Cells<\/a> by National Institute of Health (NIH)<\/a> on Wikimedia Commons is released into the public domain <\/a>(https:\/\/en.wikipedia.org\/wiki\/Public_domain).\r\n\r\n \r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\nReferences<\/span><\/div>\r\n<\/section>\r\nNational Center for Case Study Teaching in Science. (2015, August 3). Cytoskeleton structure and function. YouTube. https:\/\/www.youtube.com\/watch?v=YTv9ItGd050&feature=youtu.be<\/p>","rendered":"
<\/p>\nFigure 4.5.1 The cytoplasm is filled with many organelles, each doing their own specific jobs.<\/em><\/figcaption><\/figure>\n\nA Peek Inside the Cell<\/a><\/h1>\n<\/div>\nFigure 4.5.1 is an artist’s representation of what you might see if you could take a peek inside one of these basic building blocks of living things.\u00a0 <\/span>A\u00a0cell’s interior is obviously a crowded and busy space. It contains cytoplasm, dissolved substances, and many structures. It’s a hive of countless biochemical activities all going on at once.\u00a0<\/span><\/p>\n\nCytoplasm<\/h1>\n<\/div>\n
Cytoplasm<\/a> is a thick, usually colourless solution that fills each cell and is enclosed by the cell membrane<\/a>. Cytoplasm presses against the cell membrane, filling out the cell and giving it its shape. Sometimes, cytoplasm acts like a watery solution, and sometimes, it takes on a more gel-like consistency. In eukaryotic<\/a> cells, the cytoplasm includes all of the material inside the cell<\/a> but outside of the nucleus<\/a>, which contains its own watery substance called the nucleoplasm<\/a>. All of the organelles in eukaryotic cells (such as the endoplasmic reticulum and mitochondria) are located in the cytoplasm. The cytoplasm helps to keep them in place. It is also the site of most metabolic activities in the cell, and it allows materials to pass easily throughout the cell.<\/p>\nThe portion of the cytoplasm surrounding\u00a0organelles<\/a>\u00a0is called\u00a0cytosol<\/a><\/strong>. Cytosol is the liquid part of cytoplasm. It is composed of about 80 per cent water, and it contains dissolved salts, fatty acids<\/a>, sugars<\/a>, amino acids<\/a>, and proteins<\/a> (such as enzymes). These dissolved substances are needed to keep the cell alive and carry out metabolic processes. Enzymes<\/a> dissolved in cytosol, for example, break down larger molecules into smaller products that can then be used by organelles of the cell. Waste products are also dissolved in the cytosol before they are taken in by vacuoles or expelled from the cell.<\/p>\n\nFigure 4.5.2 The cytoskeleton gives the cell an internal structure, like the frame of a house. In this photograph, filaments and tubules of the cytoskeleton have been stained green and red, respectively, so that they can be seen clearly. The blue dots are cell nuclei.<\/em><\/figcaption><\/figure>\nCytoskeleton<\/h1>\n<\/div>\n
Although cytoplasm may appear to have no form or structure, it is actually highly organized. A framework of\u00a0protein\u00a0scaffolds called the\u00a0cytoskeleton<\/a><\/strong> provides the cytoplasm<\/a> and the cell with structure. The cytoskeleton consists of thread-like microfilaments, intermediate filaments, and microtubules that criss-cross the cytoplasm. You can see these filaments and tubules in the cells in Figure 4.5.2. As its name suggests, the cytoskeleton is like a cellular \u201cskeleton.\u201d It helps the cell maintain its shape and also helps to hold cell structures (like organelles) in place within the cytoplasm.<\/p>\n\n <\/p>\n<\/div>\n
\nFeature: Human Biology in the News<\/h1>\n<\/div>\n
News about an important study of the cytoplasm of eukaryotic\u00a0cells\u00a0came out in early 2016. Researchers in Dresden, Germany discovered that when cells are deprived of adequate\u00a0nutrients, they may essentially shut down and become dormant. Specifically, when cells do not get enough nutrients, they shut down their metabolism, their\u00a0energy level\u00a0drops, and the\u00a0pH\u00a0of their cytoplasm decreases. Their normally\u00a0liquid\u00a0cytoplasm also assumes a\u00a0solid\u00a0state. The cells appear dead, as though a kind of rigor mortis has set in. The researchers think that these changes protect the sensitive structures inside the cells and allow the cells to survive difficult conditions. If nutrients are returned to the cells, they can emerge from their dormant state unharmed. They will continue to grow and multiply when conditions improve.<\/p>\n
This important basic science\u00a0research\u00a0was\u00a0executed\u00a0on a nonhuman organism: one-celled\u00a0fungi\u00a0called yeasts. Nonetheless, it may have important implications for humans, because yeasts have eukaryotic cells with many of the same structures as human cells. Yeast cells appear to be able to “trick” death by shutting down all life processes in a controlled way. Through continued study, researchers hope to learn whether human cells can be taught this “trick” as well.<\/p>\n
\n\n4.5 Summary<\/span><\/h1>\n<\/header>\n\n\n- Cytoplasm<\/a> is a thick\u00a0solution\u00a0that fills a cell <\/a>and is enclosed by the\u00a0cell membrane<\/a>. It has many functions. It helps give the cell shape, holds organelles, and provides a site for many of the\u00a0biochemical reactions inside the cell.<\/li>\n
- The\u00a0liquid\u00a0part of the cytoplasm is called cytosol. It is mainly\u00a0water, and it contains many dissolved substances. The cytoplasm of a eukaryotic cell also contains a membrane-enclosed\u00a0nucleus\u00a0and other organelles.<\/li>\n
- The cytoskeleton is a highly organized framework of\u00a0protein\u00a0filaments and tubules that criss-cross the cytoplasm of a cell. It gives the\u00a0cell structure\u00a0and helps hold cell structures (such as organelles<\/a>) in place within the cytoplasm.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n\n
\n4.5 Review Questions<\/span><\/h1>\n<\/header>\n\n\n- Describe the composition of cytoplasm.\u00a0 Draw a picture of a cell, including the basic components required to be considered a cell, and the organelles you have learned about in this section.<\/li>\n
- What are some of the functions of cytoplasm?<\/li>\n
- Outline the structure and functions of the cytoskeleton.<\/li>\n
- Is the cytoplasm made of cells? Why or why not?<\/li>\n
- Name two types of cytoskeletal structures.<\/li>\n
- In the picture of the different cytoskeletal structures above (Figure 4.5.2), what do you notice about these different structures?<\/li>\n
- Describe one example of a metabolic process that\u00a0happens\u00a0in the cytosol.<\/li>\n
- In eukaryotic cells, all of the material inside of the cell, but\u00a0outside of the nucleus is called the ___________ .<\/li>\n
- What is the liquid part of cytoplasm called?<\/li>\n
- What chemical substance\u00a0composes\u00a0most of the cytosol?<\/li>\n
- When yeast cells deprived of\u00a0nutrients go dormant, their cytoplasm assumes a\u00a0solid state. What effect do you think a solid cytoplasm would have on normal cellular processes? Explain your answer.<\/li>\n<\/ol>\n<\/div>\n<\/div>\n\n
\n4.5 Explore More<\/span><\/h1>\n<\/header>\n\n
Figure 4.5.2 The cytoskeleton gives the cell an internal structure, like the frame of a house. In this photograph, filaments and tubules of the cytoskeleton have been stained green and red, respectively, so that they can be seen clearly. The blue dots are cell nuclei.<\/em>[\/caption]\r\nCytoskeleton<\/h1>\r\n<\/div>\r\nAlthough cytoplasm may appear to have no form or structure, it is actually highly organized. A framework of\u00a0protein\u00a0scaffolds called the\u00a0[pb_glossary id=\"5735\"]cytoskeleton[\/pb_glossary]<\/strong> provides the [pb_glossary id=\"5465\"]cytoplasm[\/pb_glossary] and the cell with structure. The cytoskeleton consists of thread-like microfilaments, intermediate filaments, and microtubules that criss-cross the cytoplasm. You can see these filaments and tubules in the cells in Figure 4.5.2. As its name suggests, the cytoskeleton is like a cellular \u201cskeleton.\u201d It helps the cell maintain its shape and also helps to hold cell structures (like organelles) in place within the cytoplasm.\r\n\r\n\r\n \r\n\r\n<\/div>\r\n\r\nFeature: Human Biology in the News<\/h1>\r\n<\/div>\r\nNews about an important study of the cytoplasm of eukaryotic\u00a0cells\u00a0came out in early 2016. Researchers in Dresden, Germany discovered that when cells are deprived of adequate\u00a0nutrients, they may essentially shut down and become dormant. Specifically, when cells do not get enough nutrients, they shut down their metabolism, their\u00a0energy level\u00a0drops, and the\u00a0pH\u00a0of their cytoplasm decreases. Their normally\u00a0liquid\u00a0cytoplasm also assumes a\u00a0solid\u00a0state. The cells appear dead, as though a kind of rigor mortis has set in. The researchers think that these changes protect the sensitive structures inside the cells and allow the cells to survive difficult conditions. If nutrients are returned to the cells, they can emerge from their dormant state unharmed. They will continue to grow and multiply when conditions improve.\r\n\r\nThis important basic science\u00a0research\u00a0was\u00a0executed\u00a0on a nonhuman organism: one-celled\u00a0fungi\u00a0called yeasts. Nonetheless, it may have important implications for humans, because yeasts have eukaryotic cells with many of the same structures as human cells. Yeast cells appear to be able to \"trick\" death by shutting down all life processes in a controlled way. Through continued study, researchers hope to learn whether human cells can be taught this \"trick\" as well.\r\n\r\n4.5 Summary<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\n \t- [pb_glossary id=\"5465\"]Cytoplasm[\/pb_glossary] is a thick\u00a0solution\u00a0that fills a [pb_glossary id=\"5665\"]cell [\/pb_glossary]and is enclosed by the\u00a0[pb_glossary id=\"5621\"]cell membrane[\/pb_glossary]. It has many functions. It helps give the cell shape, holds organelles, and provides a site for many of the\u00a0biochemical reactions inside the cell.<\/li>\r\n \t
- The\u00a0liquid\u00a0part of the cytoplasm is called cytosol. It is mainly\u00a0water, and it contains many dissolved substances. The cytoplasm of a eukaryotic cell also contains a membrane-enclosed\u00a0nucleus\u00a0and other organelles.<\/li>\r\n \t
- The cytoskeleton is a highly organized framework of\u00a0protein\u00a0filaments and tubules that criss-cross the cytoplasm of a cell. It gives the\u00a0cell structure\u00a0and helps hold cell structures (such as [pb_glossary id=\"5557\"]organelles[\/pb_glossary]) in place within the cytoplasm.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n
\r\n4.5 Review Questions<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\n \t- Describe the composition of cytoplasm.\u00a0 Draw a picture of a cell, including the basic components required to be considered a cell, and the organelles you have learned about in this section.<\/li>\r\n \t
- What are some of the functions of cytoplasm?<\/li>\r\n \t
- Outline the structure and functions of the cytoskeleton.<\/li>\r\n \t
- Is the cytoplasm made of cells? Why or why not?<\/li>\r\n \t
- Name two types of cytoskeletal structures.<\/li>\r\n \t
- In the picture of the different cytoskeletal structures above (Figure 4.5.2), what do you notice about these different structures?<\/li>\r\n \t
- Describe one example of a metabolic process that\u00a0happens\u00a0in the cytosol.<\/li>\r\n \t
- In eukaryotic cells, all of the material inside of the cell, but\u00a0outside of the nucleus is called the ___________ .<\/li>\r\n \t
- What is the liquid part of cytoplasm called?<\/li>\r\n \t
- What chemical substance\u00a0composes\u00a0most of the cytosol?<\/li>\r\n \t
- When yeast cells deprived of\u00a0nutrients go dormant, their cytoplasm assumes a\u00a0solid state. What effect do you think a solid cytoplasm would have on normal cellular processes? Explain your answer.<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n
\r\n4.5 Explore More<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\nhttps:\/\/www.youtube.com\/watch?v=YTv9ItGd050\r\nCytoskeleton Structure and Function, National Center for Case Study\r\nTeaching in Science, 2015.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n
Attributions<\/h2>\r\nFigure 4.5.1<\/strong>\r\n\r\nCell-organelles-labeled<\/a> by Koswac<\/a> on Wikimedia Commons is used under a CC BY-SA 4.0<\/a> (https:\/\/creativecommons.org\/licenses\/by-sa\/4.0) license.\r\n\r\nFigure 4.5.2<\/strong>\r\n\r\n\r\n\r\n\r\nCytoskeleton\/ Fluorescent Cells<\/a> by National Institute of Health (NIH)<\/a> on Wikimedia Commons is released into the public domain <\/a>(https:\/\/en.wikipedia.org\/wiki\/Public_domain).\r\n\r\n \r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\nReferences<\/span><\/div>\r\n<\/section>\r\nNational Center for Case Study Teaching in Science. (2015, August 3). Cytoskeleton structure and function. YouTube. https:\/\/www.youtube.com\/watch?v=YTv9ItGd050&feature=youtu.be<\/p>","rendered":"
<\/p>\nFigure 4.5.1 The cytoplasm is filled with many organelles, each doing their own specific jobs.<\/em><\/figcaption><\/figure>\n\nA Peek Inside the Cell<\/a><\/h1>\n<\/div>\nFigure 4.5.1 is an artist’s representation of what you might see if you could take a peek inside one of these basic building blocks of living things.\u00a0 <\/span>A\u00a0cell’s interior is obviously a crowded and busy space. It contains cytoplasm, dissolved substances, and many structures. It’s a hive of countless biochemical activities all going on at once.\u00a0<\/span><\/p>\n\nCytoplasm<\/h1>\n<\/div>\n
Cytoplasm<\/a> is a thick, usually colourless solution that fills each cell and is enclosed by the cell membrane<\/a>. Cytoplasm presses against the cell membrane, filling out the cell and giving it its shape. Sometimes, cytoplasm acts like a watery solution, and sometimes, it takes on a more gel-like consistency. In eukaryotic<\/a> cells, the cytoplasm includes all of the material inside the cell<\/a> but outside of the nucleus<\/a>, which contains its own watery substance called the nucleoplasm<\/a>. All of the organelles in eukaryotic cells (such as the endoplasmic reticulum and mitochondria) are located in the cytoplasm. The cytoplasm helps to keep them in place. It is also the site of most metabolic activities in the cell, and it allows materials to pass easily throughout the cell.<\/p>\nThe portion of the cytoplasm surrounding\u00a0organelles<\/a>\u00a0is called\u00a0cytosol<\/a><\/strong>. Cytosol is the liquid part of cytoplasm. It is composed of about 80 per cent water, and it contains dissolved salts, fatty acids<\/a>, sugars<\/a>, amino acids<\/a>, and proteins<\/a> (such as enzymes). These dissolved substances are needed to keep the cell alive and carry out metabolic processes. Enzymes<\/a> dissolved in cytosol, for example, break down larger molecules into smaller products that can then be used by organelles of the cell. Waste products are also dissolved in the cytosol before they are taken in by vacuoles or expelled from the cell.<\/p>\n\nFigure 4.5.2 The cytoskeleton gives the cell an internal structure, like the frame of a house. In this photograph, filaments and tubules of the cytoskeleton have been stained green and red, respectively, so that they can be seen clearly. The blue dots are cell nuclei.<\/em><\/figcaption><\/figure>\nCytoskeleton<\/h1>\n<\/div>\n
Although cytoplasm may appear to have no form or structure, it is actually highly organized. A framework of\u00a0protein\u00a0scaffolds called the\u00a0cytoskeleton<\/a><\/strong> provides the cytoplasm<\/a> and the cell with structure. The cytoskeleton consists of thread-like microfilaments, intermediate filaments, and microtubules that criss-cross the cytoplasm. You can see these filaments and tubules in the cells in Figure 4.5.2. As its name suggests, the cytoskeleton is like a cellular \u201cskeleton.\u201d It helps the cell maintain its shape and also helps to hold cell structures (like organelles) in place within the cytoplasm.<\/p>\n\n <\/p>\n<\/div>\n
\nFeature: Human Biology in the News<\/h1>\n<\/div>\n
News about an important study of the cytoplasm of eukaryotic\u00a0cells\u00a0came out in early 2016. Researchers in Dresden, Germany discovered that when cells are deprived of adequate\u00a0nutrients, they may essentially shut down and become dormant. Specifically, when cells do not get enough nutrients, they shut down their metabolism, their\u00a0energy level\u00a0drops, and the\u00a0pH\u00a0of their cytoplasm decreases. Their normally\u00a0liquid\u00a0cytoplasm also assumes a\u00a0solid\u00a0state. The cells appear dead, as though a kind of rigor mortis has set in. The researchers think that these changes protect the sensitive structures inside the cells and allow the cells to survive difficult conditions. If nutrients are returned to the cells, they can emerge from their dormant state unharmed. They will continue to grow and multiply when conditions improve.<\/p>\n
This important basic science\u00a0research\u00a0was\u00a0executed\u00a0on a nonhuman organism: one-celled\u00a0fungi\u00a0called yeasts. Nonetheless, it may have important implications for humans, because yeasts have eukaryotic cells with many of the same structures as human cells. Yeast cells appear to be able to “trick” death by shutting down all life processes in a controlled way. Through continued study, researchers hope to learn whether human cells can be taught this “trick” as well.<\/p>\n
\n\n4.5 Summary<\/span><\/h1>\n<\/header>\n\n\n- Cytoplasm<\/a> is a thick\u00a0solution\u00a0that fills a cell <\/a>and is enclosed by the\u00a0cell membrane<\/a>. It has many functions. It helps give the cell shape, holds organelles, and provides a site for many of the\u00a0biochemical reactions inside the cell.<\/li>\n
- The\u00a0liquid\u00a0part of the cytoplasm is called cytosol. It is mainly\u00a0water, and it contains many dissolved substances. The cytoplasm of a eukaryotic cell also contains a membrane-enclosed\u00a0nucleus\u00a0and other organelles.<\/li>\n
- The cytoskeleton is a highly organized framework of\u00a0protein\u00a0filaments and tubules that criss-cross the cytoplasm of a cell. It gives the\u00a0cell structure\u00a0and helps hold cell structures (such as organelles<\/a>) in place within the cytoplasm.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n\n
\n4.5 Review Questions<\/span><\/h1>\n<\/header>\n\n\n- Describe the composition of cytoplasm.\u00a0 Draw a picture of a cell, including the basic components required to be considered a cell, and the organelles you have learned about in this section.<\/li>\n
- What are some of the functions of cytoplasm?<\/li>\n
- Outline the structure and functions of the cytoskeleton.<\/li>\n
- Is the cytoplasm made of cells? Why or why not?<\/li>\n
- Name two types of cytoskeletal structures.<\/li>\n
- In the picture of the different cytoskeletal structures above (Figure 4.5.2), what do you notice about these different structures?<\/li>\n
- Describe one example of a metabolic process that\u00a0happens\u00a0in the cytosol.<\/li>\n
- In eukaryotic cells, all of the material inside of the cell, but\u00a0outside of the nucleus is called the ___________ .<\/li>\n
- What is the liquid part of cytoplasm called?<\/li>\n
- What chemical substance\u00a0composes\u00a0most of the cytosol?<\/li>\n
- When yeast cells deprived of\u00a0nutrients go dormant, their cytoplasm assumes a\u00a0solid state. What effect do you think a solid cytoplasm would have on normal cellular processes? Explain your answer.<\/li>\n<\/ol>\n<\/div>\n<\/div>\n\n
\n4.5 Explore More<\/span><\/h1>\n<\/header>\n\n
Feature: Human Biology in the News<\/h1>\r\n<\/div>\r\nNews about an important study of the cytoplasm of eukaryotic\u00a0cells\u00a0came out in early 2016. Researchers in Dresden, Germany discovered that when cells are deprived of adequate\u00a0nutrients, they may essentially shut down and become dormant. Specifically, when cells do not get enough nutrients, they shut down their metabolism, their\u00a0energy level\u00a0drops, and the\u00a0pH\u00a0of their cytoplasm decreases. Their normally\u00a0liquid\u00a0cytoplasm also assumes a\u00a0solid\u00a0state. The cells appear dead, as though a kind of rigor mortis has set in. The researchers think that these changes protect the sensitive structures inside the cells and allow the cells to survive difficult conditions. If nutrients are returned to the cells, they can emerge from their dormant state unharmed. They will continue to grow and multiply when conditions improve.\r\n\r\nThis important basic science\u00a0research\u00a0was\u00a0executed\u00a0on a nonhuman organism: one-celled\u00a0fungi\u00a0called yeasts. Nonetheless, it may have important implications for humans, because yeasts have eukaryotic cells with many of the same structures as human cells. Yeast cells appear to be able to \"trick\" death by shutting down all life processes in a controlled way. Through continued study, researchers hope to learn whether human cells can be taught this \"trick\" as well.\r\n\r\n4.5 Summary<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\n \t- [pb_glossary id=\"5465\"]Cytoplasm[\/pb_glossary] is a thick\u00a0solution\u00a0that fills a [pb_glossary id=\"5665\"]cell [\/pb_glossary]and is enclosed by the\u00a0[pb_glossary id=\"5621\"]cell membrane[\/pb_glossary]. It has many functions. It helps give the cell shape, holds organelles, and provides a site for many of the\u00a0biochemical reactions inside the cell.<\/li>\r\n \t
- The\u00a0liquid\u00a0part of the cytoplasm is called cytosol. It is mainly\u00a0water, and it contains many dissolved substances. The cytoplasm of a eukaryotic cell also contains a membrane-enclosed\u00a0nucleus\u00a0and other organelles.<\/li>\r\n \t
- The cytoskeleton is a highly organized framework of\u00a0protein\u00a0filaments and tubules that criss-cross the cytoplasm of a cell. It gives the\u00a0cell structure\u00a0and helps hold cell structures (such as [pb_glossary id=\"5557\"]organelles[\/pb_glossary]) in place within the cytoplasm.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n
\r\n4.5 Review Questions<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\n \t- Describe the composition of cytoplasm.\u00a0 Draw a picture of a cell, including the basic components required to be considered a cell, and the organelles you have learned about in this section.<\/li>\r\n \t
- What are some of the functions of cytoplasm?<\/li>\r\n \t
- Outline the structure and functions of the cytoskeleton.<\/li>\r\n \t
- Is the cytoplasm made of cells? Why or why not?<\/li>\r\n \t
- Name two types of cytoskeletal structures.<\/li>\r\n \t
- In the picture of the different cytoskeletal structures above (Figure 4.5.2), what do you notice about these different structures?<\/li>\r\n \t
- Describe one example of a metabolic process that\u00a0happens\u00a0in the cytosol.<\/li>\r\n \t
- In eukaryotic cells, all of the material inside of the cell, but\u00a0outside of the nucleus is called the ___________ .<\/li>\r\n \t
- What is the liquid part of cytoplasm called?<\/li>\r\n \t
- What chemical substance\u00a0composes\u00a0most of the cytosol?<\/li>\r\n \t
- When yeast cells deprived of\u00a0nutrients go dormant, their cytoplasm assumes a\u00a0solid state. What effect do you think a solid cytoplasm would have on normal cellular processes? Explain your answer.<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n
\r\n4.5 Explore More<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\nhttps:\/\/www.youtube.com\/watch?v=YTv9ItGd050\r\nCytoskeleton Structure and Function, National Center for Case Study\r\nTeaching in Science, 2015.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n
Attributions<\/h2>\r\nFigure 4.5.1<\/strong>\r\n\r\nCell-organelles-labeled<\/a> by Koswac<\/a> on Wikimedia Commons is used under a CC BY-SA 4.0<\/a> (https:\/\/creativecommons.org\/licenses\/by-sa\/4.0) license.\r\n\r\nFigure 4.5.2<\/strong>\r\n\r\n\r\n\r\n\r\nCytoskeleton\/ Fluorescent Cells<\/a> by National Institute of Health (NIH)<\/a> on Wikimedia Commons is released into the public domain <\/a>(https:\/\/en.wikipedia.org\/wiki\/Public_domain).\r\n\r\n \r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\nReferences<\/span><\/div>\r\n<\/section>\r\nNational Center for Case Study Teaching in Science. (2015, August 3). Cytoskeleton structure and function. YouTube. https:\/\/www.youtube.com\/watch?v=YTv9ItGd050&feature=youtu.be<\/p>","rendered":"
<\/p>\nFigure 4.5.1 The cytoplasm is filled with many organelles, each doing their own specific jobs.<\/em><\/figcaption><\/figure>\n\nA Peek Inside the Cell<\/a><\/h1>\n<\/div>\nFigure 4.5.1 is an artist’s representation of what you might see if you could take a peek inside one of these basic building blocks of living things.\u00a0 <\/span>A\u00a0cell’s interior is obviously a crowded and busy space. It contains cytoplasm, dissolved substances, and many structures. It’s a hive of countless biochemical activities all going on at once.\u00a0<\/span><\/p>\n\nCytoplasm<\/h1>\n<\/div>\n
Cytoplasm<\/a> is a thick, usually colourless solution that fills each cell and is enclosed by the cell membrane<\/a>. Cytoplasm presses against the cell membrane, filling out the cell and giving it its shape. Sometimes, cytoplasm acts like a watery solution, and sometimes, it takes on a more gel-like consistency. In eukaryotic<\/a> cells, the cytoplasm includes all of the material inside the cell<\/a> but outside of the nucleus<\/a>, which contains its own watery substance called the nucleoplasm<\/a>. All of the organelles in eukaryotic cells (such as the endoplasmic reticulum and mitochondria) are located in the cytoplasm. The cytoplasm helps to keep them in place. It is also the site of most metabolic activities in the cell, and it allows materials to pass easily throughout the cell.<\/p>\nThe portion of the cytoplasm surrounding\u00a0organelles<\/a>\u00a0is called\u00a0cytosol<\/a><\/strong>. Cytosol is the liquid part of cytoplasm. It is composed of about 80 per cent water, and it contains dissolved salts, fatty acids<\/a>, sugars<\/a>, amino acids<\/a>, and proteins<\/a> (such as enzymes). These dissolved substances are needed to keep the cell alive and carry out metabolic processes. Enzymes<\/a> dissolved in cytosol, for example, break down larger molecules into smaller products that can then be used by organelles of the cell. Waste products are also dissolved in the cytosol before they are taken in by vacuoles or expelled from the cell.<\/p>\n\nFigure 4.5.2 The cytoskeleton gives the cell an internal structure, like the frame of a house. In this photograph, filaments and tubules of the cytoskeleton have been stained green and red, respectively, so that they can be seen clearly. The blue dots are cell nuclei.<\/em><\/figcaption><\/figure>\nCytoskeleton<\/h1>\n<\/div>\n
Although cytoplasm may appear to have no form or structure, it is actually highly organized. A framework of\u00a0protein\u00a0scaffolds called the\u00a0cytoskeleton<\/a><\/strong> provides the cytoplasm<\/a> and the cell with structure. The cytoskeleton consists of thread-like microfilaments, intermediate filaments, and microtubules that criss-cross the cytoplasm. You can see these filaments and tubules in the cells in Figure 4.5.2. As its name suggests, the cytoskeleton is like a cellular \u201cskeleton.\u201d It helps the cell maintain its shape and also helps to hold cell structures (like organelles) in place within the cytoplasm.<\/p>\n\n <\/p>\n<\/div>\n
\nFeature: Human Biology in the News<\/h1>\n<\/div>\n
News about an important study of the cytoplasm of eukaryotic\u00a0cells\u00a0came out in early 2016. Researchers in Dresden, Germany discovered that when cells are deprived of adequate\u00a0nutrients, they may essentially shut down and become dormant. Specifically, when cells do not get enough nutrients, they shut down their metabolism, their\u00a0energy level\u00a0drops, and the\u00a0pH\u00a0of their cytoplasm decreases. Their normally\u00a0liquid\u00a0cytoplasm also assumes a\u00a0solid\u00a0state. The cells appear dead, as though a kind of rigor mortis has set in. The researchers think that these changes protect the sensitive structures inside the cells and allow the cells to survive difficult conditions. If nutrients are returned to the cells, they can emerge from their dormant state unharmed. They will continue to grow and multiply when conditions improve.<\/p>\n
This important basic science\u00a0research\u00a0was\u00a0executed\u00a0on a nonhuman organism: one-celled\u00a0fungi\u00a0called yeasts. Nonetheless, it may have important implications for humans, because yeasts have eukaryotic cells with many of the same structures as human cells. Yeast cells appear to be able to “trick” death by shutting down all life processes in a controlled way. Through continued study, researchers hope to learn whether human cells can be taught this “trick” as well.<\/p>\n
\n\n4.5 Summary<\/span><\/h1>\n<\/header>\n\n\n- Cytoplasm<\/a> is a thick\u00a0solution\u00a0that fills a cell <\/a>and is enclosed by the\u00a0cell membrane<\/a>. It has many functions. It helps give the cell shape, holds organelles, and provides a site for many of the\u00a0biochemical reactions inside the cell.<\/li>\n
- The\u00a0liquid\u00a0part of the cytoplasm is called cytosol. It is mainly\u00a0water, and it contains many dissolved substances. The cytoplasm of a eukaryotic cell also contains a membrane-enclosed\u00a0nucleus\u00a0and other organelles.<\/li>\n
- The cytoskeleton is a highly organized framework of\u00a0protein\u00a0filaments and tubules that criss-cross the cytoplasm of a cell. It gives the\u00a0cell structure\u00a0and helps hold cell structures (such as organelles<\/a>) in place within the cytoplasm.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n\n
\n4.5 Review Questions<\/span><\/h1>\n<\/header>\n\n\n- Describe the composition of cytoplasm.\u00a0 Draw a picture of a cell, including the basic components required to be considered a cell, and the organelles you have learned about in this section.<\/li>\n
- What are some of the functions of cytoplasm?<\/li>\n
- Outline the structure and functions of the cytoskeleton.<\/li>\n
- Is the cytoplasm made of cells? Why or why not?<\/li>\n
- Name two types of cytoskeletal structures.<\/li>\n
- In the picture of the different cytoskeletal structures above (Figure 4.5.2), what do you notice about these different structures?<\/li>\n
- Describe one example of a metabolic process that\u00a0happens\u00a0in the cytosol.<\/li>\n
- In eukaryotic cells, all of the material inside of the cell, but\u00a0outside of the nucleus is called the ___________ .<\/li>\n
- What is the liquid part of cytoplasm called?<\/li>\n
- What chemical substance\u00a0composes\u00a0most of the cytosol?<\/li>\n
- When yeast cells deprived of\u00a0nutrients go dormant, their cytoplasm assumes a\u00a0solid state. What effect do you think a solid cytoplasm would have on normal cellular processes? Explain your answer.<\/li>\n<\/ol>\n<\/div>\n<\/div>\n\n
\n4.5 Explore More<\/span><\/h1>\n<\/header>\n\n
4.5 Summary<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\n \t- [pb_glossary id=\"5465\"]Cytoplasm[\/pb_glossary] is a thick\u00a0solution\u00a0that fills a [pb_glossary id=\"5665\"]cell [\/pb_glossary]and is enclosed by the\u00a0[pb_glossary id=\"5621\"]cell membrane[\/pb_glossary]. It has many functions. It helps give the cell shape, holds organelles, and provides a site for many of the\u00a0biochemical reactions inside the cell.<\/li>\r\n \t
- The\u00a0liquid\u00a0part of the cytoplasm is called cytosol. It is mainly\u00a0water, and it contains many dissolved substances. The cytoplasm of a eukaryotic cell also contains a membrane-enclosed\u00a0nucleus\u00a0and other organelles.<\/li>\r\n \t
- The cytoskeleton is a highly organized framework of\u00a0protein\u00a0filaments and tubules that criss-cross the cytoplasm of a cell. It gives the\u00a0cell structure\u00a0and helps hold cell structures (such as [pb_glossary id=\"5557\"]organelles[\/pb_glossary]) in place within the cytoplasm.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n
\r\n4.5 Review Questions<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\n \t- Describe the composition of cytoplasm.\u00a0 Draw a picture of a cell, including the basic components required to be considered a cell, and the organelles you have learned about in this section.<\/li>\r\n \t
- What are some of the functions of cytoplasm?<\/li>\r\n \t
- Outline the structure and functions of the cytoskeleton.<\/li>\r\n \t
- Is the cytoplasm made of cells? Why or why not?<\/li>\r\n \t
- Name two types of cytoskeletal structures.<\/li>\r\n \t
- In the picture of the different cytoskeletal structures above (Figure 4.5.2), what do you notice about these different structures?<\/li>\r\n \t
- Describe one example of a metabolic process that\u00a0happens\u00a0in the cytosol.<\/li>\r\n \t
- In eukaryotic cells, all of the material inside of the cell, but\u00a0outside of the nucleus is called the ___________ .<\/li>\r\n \t
- What is the liquid part of cytoplasm called?<\/li>\r\n \t
- What chemical substance\u00a0composes\u00a0most of the cytosol?<\/li>\r\n \t
- When yeast cells deprived of\u00a0nutrients go dormant, their cytoplasm assumes a\u00a0solid state. What effect do you think a solid cytoplasm would have on normal cellular processes? Explain your answer.<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n
\r\n4.5 Explore More<\/span><\/h1>\r\n<\/header>\r\n\r\n\r\nhttps:\/\/www.youtube.com\/watch?v=YTv9ItGd050\r\nCytoskeleton Structure and Function, National Center for Case Study\r\nTeaching in Science, 2015.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n
Attributions<\/h2>\r\nFigure 4.5.1<\/strong>\r\n\r\nCell-organelles-labeled<\/a> by Koswac<\/a> on Wikimedia Commons is used under a CC BY-SA 4.0<\/a> (https:\/\/creativecommons.org\/licenses\/by-sa\/4.0) license.\r\n\r\nFigure 4.5.2<\/strong>\r\n\r\n\r\n\r\n\r\nCytoskeleton\/ Fluorescent Cells<\/a> by National Institute of Health (NIH)<\/a> on Wikimedia Commons is released into the public domain <\/a>(https:\/\/en.wikipedia.org\/wiki\/Public_domain).\r\n\r\n \r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\nReferences<\/span><\/div>\r\n<\/section>\r\nNational Center for Case Study Teaching in Science. (2015, August 3). Cytoskeleton structure and function. YouTube. https:\/\/www.youtube.com\/watch?v=YTv9ItGd050&feature=youtu.be<\/p>","rendered":"
<\/p>\nFigure 4.5.1 The cytoplasm is filled with many organelles, each doing their own specific jobs.<\/em><\/figcaption><\/figure>\n\nA Peek Inside the Cell<\/a><\/h1>\n<\/div>\nFigure 4.5.1 is an artist’s representation of what you might see if you could take a peek inside one of these basic building blocks of living things.\u00a0 <\/span>A\u00a0cell’s interior is obviously a crowded and busy space. It contains cytoplasm, dissolved substances, and many structures. It’s a hive of countless biochemical activities all going on at once.\u00a0<\/span><\/p>\n\nCytoplasm<\/h1>\n<\/div>\n
Cytoplasm<\/a> is a thick, usually colourless solution that fills each cell and is enclosed by the cell membrane<\/a>. Cytoplasm presses against the cell membrane, filling out the cell and giving it its shape. Sometimes, cytoplasm acts like a watery solution, and sometimes, it takes on a more gel-like consistency. In eukaryotic<\/a> cells, the cytoplasm includes all of the material inside the cell<\/a> but outside of the nucleus<\/a>, which contains its own watery substance called the nucleoplasm<\/a>. All of the organelles in eukaryotic cells (such as the endoplasmic reticulum and mitochondria) are located in the cytoplasm. The cytoplasm helps to keep them in place. It is also the site of most metabolic activities in the cell, and it allows materials to pass easily throughout the cell.<\/p>\nThe portion of the cytoplasm surrounding\u00a0organelles<\/a>\u00a0is called\u00a0cytosol<\/a><\/strong>. Cytosol is the liquid part of cytoplasm. It is composed of about 80 per cent water, and it contains dissolved salts, fatty acids<\/a>, sugars<\/a>, amino acids<\/a>, and proteins<\/a> (such as enzymes). These dissolved substances are needed to keep the cell alive and carry out metabolic processes. Enzymes<\/a> dissolved in cytosol, for example, break down larger molecules into smaller products that can then be used by organelles of the cell. Waste products are also dissolved in the cytosol before they are taken in by vacuoles or expelled from the cell.<\/p>\n\nFigure 4.5.2 The cytoskeleton gives the cell an internal structure, like the frame of a house. In this photograph, filaments and tubules of the cytoskeleton have been stained green and red, respectively, so that they can be seen clearly. The blue dots are cell nuclei.<\/em><\/figcaption><\/figure>\nCytoskeleton<\/h1>\n<\/div>\n
Although cytoplasm may appear to have no form or structure, it is actually highly organized. A framework of\u00a0protein\u00a0scaffolds called the\u00a0cytoskeleton<\/a><\/strong> provides the cytoplasm<\/a> and the cell with structure. The cytoskeleton consists of thread-like microfilaments, intermediate filaments, and microtubules that criss-cross the cytoplasm. You can see these filaments and tubules in the cells in Figure 4.5.2. As its name suggests, the cytoskeleton is like a cellular \u201cskeleton.\u201d It helps the cell maintain its shape and also helps to hold cell structures (like organelles) in place within the cytoplasm.<\/p>\n\n <\/p>\n<\/div>\n
\nFeature: Human Biology in the News<\/h1>\n<\/div>\n
News about an important study of the cytoplasm of eukaryotic\u00a0cells\u00a0came out in early 2016. Researchers in Dresden, Germany discovered that when cells are deprived of adequate\u00a0nutrients, they may essentially shut down and become dormant. Specifically, when cells do not get enough nutrients, they shut down their metabolism, their\u00a0energy level\u00a0drops, and the\u00a0pH\u00a0of their cytoplasm decreases. Their normally\u00a0liquid\u00a0cytoplasm also assumes a\u00a0solid\u00a0state. The cells appear dead, as though a kind of rigor mortis has set in. The researchers think that these changes protect the sensitive structures inside the cells and allow the cells to survive difficult conditions. If nutrients are returned to the cells, they can emerge from their dormant state unharmed. They will continue to grow and multiply when conditions improve.<\/p>\n
This important basic science\u00a0research\u00a0was\u00a0executed\u00a0on a nonhuman organism: one-celled\u00a0fungi\u00a0called yeasts. Nonetheless, it may have important implications for humans, because yeasts have eukaryotic cells with many of the same structures as human cells. Yeast cells appear to be able to “trick” death by shutting down all life processes in a controlled way. Through continued study, researchers hope to learn whether human cells can be taught this “trick” as well.<\/p>\n
\n\n4.5 Summary<\/span><\/h1>\n<\/header>\n\n\n- Cytoplasm<\/a> is a thick\u00a0solution\u00a0that fills a cell <\/a>and is enclosed by the\u00a0cell membrane<\/a>. It has many functions. It helps give the cell shape, holds organelles, and provides a site for many of the\u00a0biochemical reactions inside the cell.<\/li>\n
- The\u00a0liquid\u00a0part of the cytoplasm is called cytosol. It is mainly\u00a0water, and it contains many dissolved substances. The cytoplasm of a eukaryotic cell also contains a membrane-enclosed\u00a0nucleus\u00a0and other organelles.<\/li>\n
- The cytoskeleton is a highly organized framework of\u00a0protein\u00a0filaments and tubules that criss-cross the cytoplasm of a cell. It gives the\u00a0cell structure\u00a0and helps hold cell structures (such as organelles<\/a>) in place within the cytoplasm.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n\n
\n4.5 Review Questions<\/span><\/h1>\n<\/header>\n\n\n- Describe the composition of cytoplasm.\u00a0 Draw a picture of a cell, including the basic components required to be considered a cell, and the organelles you have learned about in this section.<\/li>\n
- What are some of the functions of cytoplasm?<\/li>\n
- Outline the structure and functions of the cytoskeleton.<\/li>\n
- Is the cytoplasm made of cells? Why or why not?<\/li>\n
- Name two types of cytoskeletal structures.<\/li>\n
- In the picture of the different cytoskeletal structures above (Figure 4.5.2), what do you notice about these different structures?<\/li>\n
- Describe one example of a metabolic process that\u00a0happens\u00a0in the cytosol.<\/li>\n
- In eukaryotic cells, all of the material inside of the cell, but\u00a0outside of the nucleus is called the ___________ .<\/li>\n
- What is the liquid part of cytoplasm called?<\/li>\n
- What chemical substance\u00a0composes\u00a0most of the cytosol?<\/li>\n
- When yeast cells deprived of\u00a0nutrients go dormant, their cytoplasm assumes a\u00a0solid state. What effect do you think a solid cytoplasm would have on normal cellular processes? Explain your answer.<\/li>\n<\/ol>\n<\/div>\n<\/div>\n\n
\n4.5 Explore More<\/span><\/h1>\n<\/header>\n\n
- \r\n \t
- [pb_glossary id=\"5465\"]Cytoplasm[\/pb_glossary] is a thick\u00a0solution\u00a0that fills a [pb_glossary id=\"5665\"]cell [\/pb_glossary]and is enclosed by the\u00a0[pb_glossary id=\"5621\"]cell membrane[\/pb_glossary]. It has many functions. It helps give the cell shape, holds organelles, and provides a site for many of the\u00a0biochemical reactions inside the cell.<\/li>\r\n \t
- The\u00a0liquid\u00a0part of the cytoplasm is called cytosol. It is mainly\u00a0water, and it contains many dissolved substances. The cytoplasm of a eukaryotic cell also contains a membrane-enclosed\u00a0nucleus\u00a0and other organelles.<\/li>\r\n \t
- The cytoskeleton is a highly organized framework of\u00a0protein\u00a0filaments and tubules that criss-cross the cytoplasm of a cell. It gives the\u00a0cell structure\u00a0and helps hold cell structures (such as [pb_glossary id=\"5557\"]organelles[\/pb_glossary]) in place within the cytoplasm.<\/li>\r\n<\/ul>\r\n<\/div>\r\n<\/div>\r\n
\r\n 4.5 Review Questions<\/span><\/h1>\r\n<\/header>\r\n
\r\n- \r\n \t
- Describe the composition of cytoplasm.\u00a0 Draw a picture of a cell, including the basic components required to be considered a cell, and the organelles you have learned about in this section.<\/li>\r\n \t
- What are some of the functions of cytoplasm?<\/li>\r\n \t
- Outline the structure and functions of the cytoskeleton.<\/li>\r\n \t
- Is the cytoplasm made of cells? Why or why not?<\/li>\r\n \t
- Name two types of cytoskeletal structures.<\/li>\r\n \t
- In the picture of the different cytoskeletal structures above (Figure 4.5.2), what do you notice about these different structures?<\/li>\r\n \t
- Describe one example of a metabolic process that\u00a0happens\u00a0in the cytosol.<\/li>\r\n \t
- In eukaryotic cells, all of the material inside of the cell, but\u00a0outside of the nucleus is called the ___________ .<\/li>\r\n \t
- What is the liquid part of cytoplasm called?<\/li>\r\n \t
- What chemical substance\u00a0composes\u00a0most of the cytosol?<\/li>\r\n \t
- When yeast cells deprived of\u00a0nutrients go dormant, their cytoplasm assumes a\u00a0solid state. What effect do you think a solid cytoplasm would have on normal cellular processes? Explain your answer.<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n
\r\n 4.5 Explore More<\/span><\/h1>\r\n<\/header>\r\n
\r\n\r\nhttps:\/\/www.youtube.com\/watch?v=YTv9ItGd050\r\nCytoskeleton Structure and Function, National Center for Case Study\r\nTeaching in Science, 2015.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n
Attributions<\/h2>\r\nFigure 4.5.1<\/strong>\r\n\r\nCell-organelles-labeled<\/a> by Koswac<\/a> on Wikimedia Commons is used under a CC BY-SA 4.0<\/a> (https:\/\/creativecommons.org\/licenses\/by-sa\/4.0) license.\r\n\r\nFigure 4.5.2<\/strong>\r\n\r\n
\r\n \r\n\r\nCytoskeleton\/ Fluorescent Cells<\/a> by National Institute of Health (NIH)<\/a> on Wikimedia Commons is released into the public domain <\/a>(https:\/\/en.wikipedia.org\/wiki\/Public_domain).\r\n\r\n \r\n\r\n<\/div>\r\n<\/div>\r\n<\/div>\r\nReferences<\/span><\/div>\r\n<\/section>\r\nNational Center for Case Study Teaching in Science. (2015, August 3). Cytoskeleton structure and function. YouTube. https:\/\/www.youtube.com\/watch?v=YTv9ItGd050&feature=youtu.be<\/p>","rendered":"
<\/p>\n
Figure 4.5.1 The cytoplasm is filled with many organelles, each doing their own specific jobs.<\/em><\/figcaption><\/figure>\n \nA Peek Inside the Cell<\/a><\/h1>\n<\/div>\n
Figure 4.5.1 is an artist’s representation of what you might see if you could take a peek inside one of these basic building blocks of living things.\u00a0 <\/span>A\u00a0cell’s interior is obviously a crowded and busy space. It contains cytoplasm, dissolved substances, and many structures. It’s a hive of countless biochemical activities all going on at once.\u00a0<\/span><\/p>\n
\nCytoplasm<\/h1>\n<\/div>\n
Cytoplasm<\/a> is a thick, usually colourless solution that fills each cell and is enclosed by the cell membrane<\/a>. Cytoplasm presses against the cell membrane, filling out the cell and giving it its shape. Sometimes, cytoplasm acts like a watery solution, and sometimes, it takes on a more gel-like consistency. In eukaryotic<\/a> cells, the cytoplasm includes all of the material inside the cell<\/a> but outside of the nucleus<\/a>, which contains its own watery substance called the nucleoplasm<\/a>. All of the organelles in eukaryotic cells (such as the endoplasmic reticulum and mitochondria) are located in the cytoplasm. The cytoplasm helps to keep them in place. It is also the site of most metabolic activities in the cell, and it allows materials to pass easily throughout the cell.<\/p>\n
The portion of the cytoplasm surrounding\u00a0organelles<\/a>\u00a0is called\u00a0cytosol<\/a><\/strong>. Cytosol is the liquid part of cytoplasm. It is composed of about 80 per cent water, and it contains dissolved salts, fatty acids<\/a>, sugars<\/a>, amino acids<\/a>, and proteins<\/a> (such as enzymes). These dissolved substances are needed to keep the cell alive and carry out metabolic processes. Enzymes<\/a> dissolved in cytosol, for example, break down larger molecules into smaller products that can then be used by organelles of the cell. Waste products are also dissolved in the cytosol before they are taken in by vacuoles or expelled from the cell.<\/p>\n
\nFigure 4.5.2 The cytoskeleton gives the cell an internal structure, like the frame of a house. In this photograph, filaments and tubules of the cytoskeleton have been stained green and red, respectively, so that they can be seen clearly. The blue dots are cell nuclei.<\/em><\/figcaption><\/figure>\n Cytoskeleton<\/h1>\n<\/div>\n
Although cytoplasm may appear to have no form or structure, it is actually highly organized. A framework of\u00a0protein\u00a0scaffolds called the\u00a0cytoskeleton<\/a><\/strong> provides the cytoplasm<\/a> and the cell with structure. The cytoskeleton consists of thread-like microfilaments, intermediate filaments, and microtubules that criss-cross the cytoplasm. You can see these filaments and tubules in the cells in Figure 4.5.2. As its name suggests, the cytoskeleton is like a cellular \u201cskeleton.\u201d It helps the cell maintain its shape and also helps to hold cell structures (like organelles) in place within the cytoplasm.<\/p>\n
\n<\/p>\n<\/div>\n
\nFeature: Human Biology in the News<\/h1>\n<\/div>\n
News about an important study of the cytoplasm of eukaryotic\u00a0cells\u00a0came out in early 2016. Researchers in Dresden, Germany discovered that when cells are deprived of adequate\u00a0nutrients, they may essentially shut down and become dormant. Specifically, when cells do not get enough nutrients, they shut down their metabolism, their\u00a0energy level\u00a0drops, and the\u00a0pH\u00a0of their cytoplasm decreases. Their normally\u00a0liquid\u00a0cytoplasm also assumes a\u00a0solid\u00a0state. The cells appear dead, as though a kind of rigor mortis has set in. The researchers think that these changes protect the sensitive structures inside the cells and allow the cells to survive difficult conditions. If nutrients are returned to the cells, they can emerge from their dormant state unharmed. They will continue to grow and multiply when conditions improve.<\/p>\n
This important basic science\u00a0research\u00a0was\u00a0executed\u00a0on a nonhuman organism: one-celled\u00a0fungi\u00a0called yeasts. Nonetheless, it may have important implications for humans, because yeasts have eukaryotic cells with many of the same structures as human cells. Yeast cells appear to be able to “trick” death by shutting down all life processes in a controlled way. Through continued study, researchers hope to learn whether human cells can be taught this “trick” as well.<\/p>\n
\n\n 4.5 Summary<\/span><\/h1>\n<\/header>\n
\n- \n
- Cytoplasm<\/a> is a thick\u00a0solution\u00a0that fills a cell <\/a>and is enclosed by the\u00a0cell membrane<\/a>. It has many functions. It helps give the cell shape, holds organelles, and provides a site for many of the\u00a0biochemical reactions inside the cell.<\/li>\n
- The\u00a0liquid\u00a0part of the cytoplasm is called cytosol. It is mainly\u00a0water, and it contains many dissolved substances. The cytoplasm of a eukaryotic cell also contains a membrane-enclosed\u00a0nucleus\u00a0and other organelles.<\/li>\n
- The cytoskeleton is a highly organized framework of\u00a0protein\u00a0filaments and tubules that criss-cross the cytoplasm of a cell. It gives the\u00a0cell structure\u00a0and helps hold cell structures (such as organelles<\/a>) in place within the cytoplasm.<\/li>\n<\/ul>\n<\/div>\n<\/div>\n
\n\n 4.5 Review Questions<\/span><\/h1>\n<\/header>\n
\n- \n
- Describe the composition of cytoplasm.\u00a0 Draw a picture of a cell, including the basic components required to be considered a cell, and the organelles you have learned about in this section.<\/li>\n
- What are some of the functions of cytoplasm?<\/li>\n
- Outline the structure and functions of the cytoskeleton.<\/li>\n
- Is the cytoplasm made of cells? Why or why not?<\/li>\n
- Name two types of cytoskeletal structures.<\/li>\n
- In the picture of the different cytoskeletal structures above (Figure 4.5.2), what do you notice about these different structures?<\/li>\n
- Describe one example of a metabolic process that\u00a0happens\u00a0in the cytosol.<\/li>\n
- In eukaryotic cells, all of the material inside of the cell, but\u00a0outside of the nucleus is called the ___________ .<\/li>\n
- What is the liquid part of cytoplasm called?<\/li>\n
- What chemical substance\u00a0composes\u00a0most of the cytosol?<\/li>\n
- When yeast cells deprived of\u00a0nutrients go dormant, their cytoplasm assumes a\u00a0solid state. What effect do you think a solid cytoplasm would have on normal cellular processes? Explain your answer.<\/li>\n<\/ol>\n<\/div>\n<\/div>\n\n
\n 4.5 Explore More<\/span><\/h1>\n<\/header>\n
\n
- Cytoplasm<\/a> is a thick\u00a0solution\u00a0that fills a cell <\/a>and is enclosed by the\u00a0cell membrane<\/a>. It has many functions. It helps give the cell shape, holds organelles, and provides a site for many of the\u00a0biochemical reactions inside the cell.<\/li>\n
![Cell-organelles-labeled<\/a> by](\"https:\/\/commons.wikimedia.org\/wiki\/File:Cell-organelles-labeled.png\"){kind=link}
![Cytoskeleton\/ Fluorescent Cells<\/a> by](\"https:\/\/commons.wikimedia.org\/wiki\/File:FluorescentCells.jpg\"){kind=link}