{"id":426,"date":"2024-03-27T01:13:35","date_gmt":"2024-03-27T01:13:35","guid":{"rendered":"https:\/\/pressbooks.justwrite.in\/interactive-biology-secondary\/?post_type=chapter&#038;p=426"},"modified":"2024-11-30T06:30:37","modified_gmt":"2024-11-30T06:30:37","slug":"1-6-a-lipids","status":"publish","type":"chapter","link":"https:\/\/pressbooks.justwrite.in\/interactive-biology-secondary\/chapter\/1-6-a-lipids\/","title":{"raw":"1.6 a , Chemical constituents of cell- Lipids","rendered":"1.6 a , Chemical constituents of cell- Lipids"},"content":{"raw":"<h1>Lipids<\/h1>\r\n<ul>\r\n \t<li>These are next abundant macromolecules of the cell. They are composed of carbon, hydrogen and may also oxygen, nitrogen, sulfur and phosphorus.<\/li>\r\n \t<li>They are energy-storing molecules.<\/li>\r\n \t<li>They are structural components of membranes and hormones.<\/li>\r\n<\/ul>\r\n<p id=\"fs-id1167662475090\"><span style=\"font-family: 'Cormorant Garamond', serif;font-size: 1.602em;font-weight: bold\">Fatty Acids\u00a0<\/span><\/p>\r\nThese are type of lipids that contain long chain hydrocarbon with carboxylic acid functional group. They are hydrophobic and nonpolar. They are of two types as\r\n<ol>\r\n \t<li><strong>Saturated Fatty acids:<\/strong> These are fatty acids with hydrocarbon chains that contain only single bonds. As t<span style=\"text-align: initial;font-size: 1em\">hey have the greatest number of hydrogen atoms possible they are therefore referred as ,\u201csaturated\u201d (with hydrogen). They have straight\u00a0 flexible back bone. Lipids containing saturated fatty acids are solids at room temperature.<\/span><\/li>\r\n \t<li><span style=\"text-align: initial;font-size: 1em\"><strong>Unsaturated Fatty acids :<\/strong> These are fatty acids with hydrocarbon chains containing at least one double bond . They are called unsaturated because <\/span><span style=\"text-align: initial;font-size: 1em\">they have fewer hydrogen atoms. Unsaturated fatty acids because of their double bonds have bend in their<\/span><span style=\"text-align: initial;font-size: 1em\">\u00a0<\/span><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00008\" style=\"text-align: initial;font-size: 1em\">carbon skeleton. Lipids containing unsaturated fatty acids are liquids.<\/span><\/li>\r\n<\/ol>\r\n<span style=\"font-family: 'Cormorant Garamond', serif;font-size: 1.602em;font-weight: bold\">Triacylglycerides<\/span>\r\n\r\nThese are fattyacids chemically linked to a glycerol molecule.\r\n\r\nThese are called simple lipids as they are composed only of two compounds namely glycerol and fattyacids.\r\n\r\nThese are primarily present in the adipose tissue and sebum.\r\n\r\nThey are energy storing molecules and has more calorific value than carbohydrates and proteins.\r\n\r\n<section id=\"fs-id1167662577822\" data-depth=\"1\">\r\n<div class=\"os-figure\" id=\"OSC_Microbio_07_03_trygly\">\r\n<figure data-id=\"OSC_Microbio_07_03_trygly\"><span data-type=\"media\" id=\"fs-id1167662614515\" data-alt=\"A diagram showing a triglyceride is made of a glycerol and three fatty acids. Glycerol is a 3 carbon chain with an OH on each carbon. The H on each OH is highlighted. Fatty acids are long carbon chains with a C that has an OH and a double bonded O at the end. The OH of this C is highlighted. Three fatty acids are shown. Each fatty acid binds to one of the O\u2019s from the OH groups on each Carbon on glycerol. The result is a triglyceride (or neutral fat) and 3 water molecules.\"><img data-media-type=\"image\/jpeg\" alt=\"A diagram showing a triglyceride is made of a glycerol and three fatty acids. Glycerol is a 3 carbon chain with an OH on each carbon. The H on each OH is highlighted. Fatty acids are long carbon chains with a C that has an OH and a double bonded O at the end. The OH of this C is highlighted. Three fatty acids are shown. Each fatty acid binds to one of the O\u2019s from the OH groups on each Carbon on glycerol. The result is a triglyceride (or neutral fat) and 3 water molecules.\" width=\"1300\" height=\"395\" src=\"https:\/\/openstax.org\/apps\/archive\/20240226.174525\/resources\/4efff70e4be2438a96ad46923a5a9cdbbbf769ef\" \/><\/span><\/figure>\r\n<div style=\"text-align: center\"><span id=\"output\" class=\"outputbox\"><a href=\"https:\/\/openstax.org\/books\/microbiology\/pages\/7-3-lipids#OSC_Microbio_07_03_trygly\" target=\"_blank\" rel=\"noopener\">\"Triglyceride\"<\/a><span>\u00a0<\/span>by<span>\u00a0<\/span><a>Openstax<\/a><a><\/a><a><\/a><span>\u00a0<\/span>is licensed under<span>\u00a0<\/span><a href=\"http:\/\/creativecommons.org\/licenses\/by\/4.0\" target=\"_blank\" rel=\"noopener\">CC BY 4.0<\/a><a><\/a><\/span><span><\/span><\/div>\r\n<div class=\"os-caption-container\"><span style=\"font-family: 'Cormorant Garamond', serif;font-size: 1.602em;font-weight: bold\">Phospholipids\u00a0<\/span><\/div>\r\n<div>These are complex lipids.<\/div>\r\n<div>These are composed of glycerol esterified with two fatty acids<\/div>\r\n<div>The third binding position of glycerol is attached with a modified phosphate group.<\/div>\r\n<\/div>\r\n<\/section><section id=\"fs-id1167662514925\" data-depth=\"1\">\r\n<div class=\"os-figure\" id=\"OSC_Microbio_07_03_phospholip\">\r\n<figure data-id=\"OSC_Microbio_07_03_phospholip\"><span data-type=\"media\" id=\"fs-id1167662615737\" data-alt=\"A drawing of a phospholipid as a large circle with 2 rectangles projecting from the bottom. The circle is labeled hydrophilic head and contains glycerol (which contains 3 carbons). Attached ot one of these carbons is a phosphate (which is a phosphorus attached to 4 oxygen atoms). The rectangles at the bottom are both long carbon chains labeled as hydrophobic tails. One of the chains is a straight zig-zag line and is labeled saturated fatty acid. The other has a double bond that creates a bend in the line; this is labeled unsaturated fatty acid.\"><img data-media-type=\"image\/jpeg\" alt=\"A drawing of a phospholipid as a large circle with 2 rectangles projecting from the bottom. The circle is labeled hydrophilic head and contains glycerol (which contains 3 carbons). Attached ot one of these carbons is a phosphate (which is a phosphorus attached to 4 oxygen atoms). The rectangles at the bottom are both long carbon chains labeled as hydrophobic tails. One of the chains is a straight zig-zag line and is labeled saturated fatty acid. The other has a double bond that creates a bend in the line; this is labeled unsaturated fatty acid.\" width=\"361\" height=\"340\" src=\"https:\/\/openstax.org\/apps\/archive\/20240226.174525\/resources\/1826a2a1ae4622f4c87b06bad15a4cd091ec728d\" class=\"aligncenter\" \/><\/span><\/figure>\r\n<div style=\"text-align: center\"><span id=\"output\" class=\"outputbox\"><a href=\"https:\/\/openstax.org\/books\/microbiology\/pages\/7-3-lipids#OSC_Microbio_07_03_phospholip\" target=\"_blank\" rel=\"noopener\">\"Phospholipids\"<\/a><span>\u00a0<\/span>by<span>\u00a0<\/span><a>Openstax<\/a><a><\/a><a><\/a><span>\u00a0<\/span>is licensed under<span>\u00a0<\/span><a href=\"http:\/\/creativecommons.org\/licenses\/by\/4.0\" target=\"_blank\" rel=\"noopener\">CC BY 4.0<\/a><a><\/a><\/span><span><\/span><\/div>\r\n<div class=\"os-caption-container\">Unlike other lipids Phospholipids are hydrophilic as they have a negatively charged phosphate group which can attract water.<\/div>\r\n<\/div>\r\n<p id=\"fs-id1167662690143\">\u00a0The hydrophilic portion of the phospholipid is often referred to as a polar \u201chead,\u201d and the long hydrocarbon chains as nonpolar \u201ctails.\u201d<\/p>\r\nAs these contain both molecule hydrophobic portion and a hydrophilic moiety, they are said to be<span>\u00a0<\/span><span data-type=\"term\" id=\"term-00023\">amphipathic<\/span>.\r\n\r\nThis amphipathic nature enables them to form unique functional structures in aqueous environments.\r\n\r\nThe amphipathic nature of phospholipids enables them to form uniquely functional structures in aqueous environments like\r\n\r\n<strong>Miscelles<\/strong> : These are spherical assemblies containing a hydrophobic phospholipid tail in the interior and the polar head groups on the outer surface.\r\n\r\n<strong><span data-type=\"term\" id=\"term-00026\">Lipid-bilayer <\/span>sheets, or <span data-type=\"term\" id=\"term-00027\">unit membranes: <\/span><\/strong><span data-type=\"term\" id=\"term-00027\">These<\/span>\u00a0are large, two-dimensional assemblies of<span>\u00a0<\/span><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00028\">phospholipid<\/span>s congregated tail to tail. The cell membranes of cells are made of lipid-bilayer sheets.\r\n\r\n<strong>[pb_glossary id=\"859\"]Liposomes:[\/pb_glossary]<\/strong> These are lipid spheres formed by lipid bilayer sheets.\r\n\r\n&nbsp;\r\n\r\n&nbsp;\r\n<div class=\"os-figure\" id=\"OSC_Microbio_07_03_micelle\">\r\n<figure data-id=\"OSC_Microbio_07_03_micelle\"><span data-type=\"media\" id=\"fs-id1167662406507\" data-alt=\"A lipid bilayer sheet is when there are 2 rows of phospholipids across each other forming a flat surface. The polar heads of all phospholipids are towards the outside of the sheet, and the nonpolar tails are towards the inside. This lipid-bilyaer can also form a sphere. The lipid-bilayer forms the surface of the sphere; the polar heads are on the outside of the sphere and lining the inside space of the sphere. Lipids can also form a single-layer sphere where the outside of the sphere is the polar heads and the nonpolar tails fill the center of the sphere.\"><img data-media-type=\"image\/jpeg\" alt=\"A lipid bilayer sheet is when there are 2 rows of phospholipids across each other forming a flat surface. The polar heads of all phospholipids are towards the outside of the sheet, and the nonpolar tails are towards the inside. This lipid-bilyaer can also form a sphere. The lipid-bilayer forms the surface of the sphere; the polar heads are on the outside of the sphere and lining the inside space of the sphere. Lipids can also form a single-layer sphere where the outside of the sphere is the polar heads and the nonpolar tails fill the center of the sphere.\" width=\"525\" height=\"236\" src=\"https:\/\/openstax.org\/apps\/archive\/20240226.174525\/resources\/f8689731ee7ce1cf711376fe23dbafbceac4da9f\" class=\"aligncenter\" \/><\/span><\/figure>\r\n<\/div>\r\n<div data-type=\"note\" id=\"fs-id1167662487861\" class=\"microbiology check-your-understanding ui-has-child-title\">\r\n<p style=\"text-align: center\"><a href=\"https:\/\/openstax.org\/books\/microbiology\/pages\/7-3-lipids#OSC_Microbio_07_03_micelle\" target=\"_blank\" rel=\"noopener\">\"Miscelles\"<\/a><span>\u00a0by\u00a0<\/span><a>Openstax<\/a><a><\/a><a><\/a><span>\u00a0is licensed under\u00a0<\/span><a href=\"http:\/\/creativecommons.org\/licenses\/by\/4.0\" target=\"_blank\" rel=\"noopener\">CC BY 4.0<\/a><\/p>\r\n\r\n<header>\r\n<h2>Glycolipids<\/h2>\r\n<span>A <\/span><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00024\">polar head group<\/span>can be more complex than a simple phosphate moiety. Glycolipids are examples in which carbohydrates are bonded to the lipids\u2019 head groups.\r\n<h2><span>\u00a0I<\/span><span data-type=\"term\" id=\"term-00031\">soprenoids<\/span><\/h2>\r\n<\/header><\/div>\r\n<\/section><section id=\"fs-id1167662616038\" data-depth=\"1\">\r\n<p id=\"fs-id1167662685607\">The<span><\/span>[pb_glossary id=\"861\"]<span>\u00a0<\/span><span data-type=\"term\" id=\"term-00031\">isoprenoids<\/span>[\/pb_glossary]<span data-type=\"term\" id=\"term-00031\"><\/span><span>\u00a0<\/span>are branched lipids, also referred to as<span>\u00a0<\/span><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00032\">terpenoids<\/span>,<\/p>\r\nThese are formed by chemical modifications of the<span>\u00a0<\/span><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00033\">isoprene<\/span><span>\u00a0<\/span>molecule.\r\n\r\nThese lipids play a wide variety of physiological roles in plants and animals.\r\n\r\nFor example, they are constituents of plant pigments like beta carotene, xanthophylls, Fragrances like menthol, camphor.\r\n\r\nLong-chain isoprenoids are also found in<span>\u00a0<\/span><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00034\">hydrophobic<\/span><span>\u00a0<\/span>oils and<span>\u00a0<\/span><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00035\">waxes<\/span>.\r\n\r\nWaxes are typically water resistant and hard at room temperature, but they soften when heated and liquefy if warmed adequately. The sebaceous glands of hair follicles in the human skin secrete sebum, which consists mainly of triacylglycerol, wax esters, and the hydrocarbon squalene.\r\n<div class=\"os-figure\" id=\"OSC_Microbio_07_03_isoprene\">\r\n<figure data-id=\"OSC_Microbio_07_03_isoprene\"><span data-type=\"media\" id=\"fs-id1167662489293\" data-alt=\"Alpha-pinene is a carbon ring with added carbon projections. Camphor is a carbon ring with added carbon projections and a double bonded oxygen on one carbon. Isophrene is a 4 carbon chain with another carbon attached to carbon 2. Limonene is a carbon ring with a carbon attached to on one end and another carbon attached to the other end; this carbon has 2 carbons attached to it. Menthol i s a carbon ring with a carbon attached to on one end and another carbon attached to the other end; this carbon has 2 carbons attached to it. One more carbon corner has an OH group. Beta-carotene is two carbon rings attached by a long carbon chain.\"><img data-media-type=\"image\/jpeg\" alt=\"Alpha-pinene is a carbon ring with added carbon projections. Camphor is a carbon ring with added carbon projections and a double bonded oxygen on one carbon. Isophrene is a 4 carbon chain with another carbon attached to carbon 2. Limonene is a carbon ring with a carbon attached to on one end and another carbon attached to the other end; this carbon has 2 carbons attached to it. Menthol i s a carbon ring with a carbon attached to on one end and another carbon attached to the other end; this carbon has 2 carbons attached to it. One more carbon corner has an OH group. Beta-carotene is two carbon rings attached by a long carbon chain.\" width=\"560\" height=\"313\" src=\"https:\/\/openstax.org\/apps\/archive\/20240226.174525\/resources\/6b063f9987ec8eb594496d4b287ec519286f66b5\" class=\"aligncenter\" \/><\/span><\/figure>\r\n<p style=\"text-align: center\"><a href=\"https:\/\/openstax.org\/books\/microbiology\/pages\/7-3-lipids#OSC_Microbio_07_03_isoprene\" target=\"_blank\" rel=\"noopener\">\"Isoprenoids\"<\/a><span>\u00a0by\u00a0<\/span><a>Openstax<\/a><a><\/a><a><\/a><span>\u00a0is licensed under\u00a0<\/span><a href=\"http:\/\/creativecommons.org\/licenses\/by\/4.0\" target=\"_blank\" rel=\"noopener\">CC BY 4.0<\/a><\/p>\r\n\r\n<div class=\"os-caption-container\"><\/div>\r\n<div>\r\n\r\n<span style=\"font-family: 'Cormorant Garamond', serif;font-size: 1.602em;font-weight: bold\">Steroids, Sterol, Cholesterol<\/span>\r\n\r\nThese are complex ring structure lipids.\r\n\r\nThey are found in cell membrane.\r\n\r\nSome function as hormones example Oestrogen.\r\n\r\n<span style=\"text-align: initial;font-size: 1em\">\u00a0The most common types of steroids are<\/span><span style=\"text-align: initial;font-size: 1em\">\u00a0<\/span><span data-type=\"term\" id=\"term-00037\" style=\"text-align: initial;font-size: 1em\"><\/span>[pb_glossary id=\"863\"]<span data-type=\"term\" id=\"term-00037\" style=\"text-align: initial;font-size: 1em\">sterol<\/span><strong style=\"text-align: initial;font-size: 1em\">s<\/strong>[\/pb_glossary]<span style=\"text-align: initial;font-size: 1em\">, which are steroids containing an OH group. These are mainly<\/span><span style=\"text-align: initial;font-size: 1em\">\u00a0<\/span><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00038\" style=\"text-align: initial;font-size: 1em\">hydrophobic<\/span><span style=\"text-align: initial;font-size: 1em\">\u00a0<\/span><span style=\"text-align: initial;font-size: 1em\">molecules, but also have hydrophilic<\/span><span style=\"text-align: initial;font-size: 1em\">\u00a0<\/span><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00039\" style=\"text-align: initial;font-size: 1em\">hydroxyl group<\/span><span style=\"text-align: initial;font-size: 1em\">s.<\/span>\r\n\r\n<strong>Cholesterol is the most common sterol found in animal tissues.<\/strong>\r\n\r\n<span style=\"text-align: initial;font-size: 1em\">\u00a0Its structure consists of four rings with a double bond in one of the rings, and a hydroxyl group at the sterol-defining position.<\/span>\r\n\r\nCholesterol strengthens cell membrane.\r\n\r\n<span style=\"text-align: initial;font-size: 1em\">\u00a0Prokaryotes generally do not produce cholesterol, although bacteria produce similar compounds called<\/span><span style=\"text-align: initial;font-size: 1em\">\u00a0<\/span><em><strong><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00041\" style=\"text-align: initial;font-size: 1em\">[pb_glossary id=\"865\"]hopanoids[\/pb_glossary]<\/span><\/strong><\/em><span style=\"text-align: initial;font-size: 1em\"><em><strong>,<\/strong><\/em> which are also multiringed structures that strengthen bacterial membranes.<\/span>\r\n\r\n<span style=\"text-align: initial;font-size: 1em\">Fungi and some protozoa produce a similar compound called<\/span><span style=\"text-align: initial;font-size: 1em\">\u00a0<\/span><strong><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00042\" style=\"text-align: initial;font-size: 1em\">ergosterol<\/span><\/strong><span style=\"text-align: initial;font-size: 1em\">, which strengthens the cell membranes of these organisms.<\/span>\r\n\r\n<\/div>\r\n<\/div>\r\n<div class=\"os-figure\" id=\"OSC_Microbio_07_03_sterols\">\r\n<figure data-id=\"OSC_Microbio_07_03_sterols\"><span data-type=\"media\" id=\"fs-id1167662491684\" data-alt=\"Cholesterol is made of 3 hexagons attached along their edges. The third hexagon has a pentagon attached along an edge. The pentagon has a carbon chain attached to it. Hopene is made of 4 hexagons attached along their edges. The last hexagon has a pentagon. The pentagon has a short carbon chain.\"><img data-media-type=\"image\/jpeg\" alt=\"Cholesterol is made of 3 hexagons attached along their edges. The third hexagon has a pentagon attached along an edge. The pentagon has a carbon chain attached to it. Hopene is made of 4 hexagons attached along their edges. The last hexagon has a pentagon. The pentagon has a short carbon chain.\" width=\"484\" height=\"148\" src=\"https:\/\/openstax.org\/apps\/archive\/20240226.174525\/resources\/f396bb45cb4e2fa96b41d7d43994cd22d4e25cf9\" class=\"aligncenter\" \/><\/span><\/figure>\r\n<p style=\"text-align: center\"><a href=\"https:\/\/openstax.org\/books\/microbiology\/pages\/7-3-lipids#OSC_Microbio_07_03_sterols\" target=\"_blank\" rel=\"noopener\">Sterols\"<\/a><span>\u00a0by\u00a0<\/span><a>Openstax<\/a><span>\u00a0is licensed under\u00a0<\/span><a href=\"http:\/\/creativecommons.org\/licenses\/by\/4.0\" target=\"_blank\" rel=\"noopener\">CC BY 4.0<\/a><\/p>\r\n\r\n<\/div>\r\n<h2>Test your Understanding<\/h2>\r\n<span>[h5p id=\"110\"]<\/span>\r\n\r\n<\/section>","rendered":"<h1>Lipids<\/h1>\n<ul>\n<li>These are next abundant macromolecules of the cell. They are composed of carbon, hydrogen and may also oxygen, nitrogen, sulfur and phosphorus.<\/li>\n<li>They are energy-storing molecules.<\/li>\n<li>They are structural components of membranes and hormones.<\/li>\n<\/ul>\n<p id=\"fs-id1167662475090\"><span style=\"font-family: 'Cormorant Garamond', serif;font-size: 1.602em;font-weight: bold\">Fatty Acids\u00a0<\/span><\/p>\n<p>These are type of lipids that contain long chain hydrocarbon with carboxylic acid functional group. They are hydrophobic and nonpolar. They are of two types as<\/p>\n<ol>\n<li><strong>Saturated Fatty acids:<\/strong> These are fatty acids with hydrocarbon chains that contain only single bonds. As t<span style=\"text-align: initial;font-size: 1em\">hey have the greatest number of hydrogen atoms possible they are therefore referred as ,\u201csaturated\u201d (with hydrogen). They have straight\u00a0 flexible back bone. Lipids containing saturated fatty acids are solids at room temperature.<\/span><\/li>\n<li><span style=\"text-align: initial;font-size: 1em\"><strong>Unsaturated Fatty acids :<\/strong> These are fatty acids with hydrocarbon chains containing at least one double bond . They are called unsaturated because <\/span><span style=\"text-align: initial;font-size: 1em\">they have fewer hydrogen atoms. Unsaturated fatty acids because of their double bonds have bend in their<\/span><span style=\"text-align: initial;font-size: 1em\">\u00a0<\/span><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00008\" style=\"text-align: initial;font-size: 1em\">carbon skeleton. Lipids containing unsaturated fatty acids are liquids.<\/span><\/li>\n<\/ol>\n<p><span style=\"font-family: 'Cormorant Garamond', serif;font-size: 1.602em;font-weight: bold\">Triacylglycerides<\/span><\/p>\n<p>These are fattyacids chemically linked to a glycerol molecule.<\/p>\n<p>These are called simple lipids as they are composed only of two compounds namely glycerol and fattyacids.<\/p>\n<p>These are primarily present in the adipose tissue and sebum.<\/p>\n<p>They are energy storing molecules and has more calorific value than carbohydrates and proteins.<\/p>\n<section id=\"fs-id1167662577822\" data-depth=\"1\">\n<div class=\"os-figure\" id=\"OSC_Microbio_07_03_trygly\">\n<figure data-id=\"OSC_Microbio_07_03_trygly\"><span data-type=\"media\" id=\"fs-id1167662614515\" data-alt=\"A diagram showing a triglyceride is made of a glycerol and three fatty acids. Glycerol is a 3 carbon chain with an OH on each carbon. The H on each OH is highlighted. Fatty acids are long carbon chains with a C that has an OH and a double bonded O at the end. The OH of this C is highlighted. Three fatty acids are shown. Each fatty acid binds to one of the O\u2019s from the OH groups on each Carbon on glycerol. The result is a triglyceride (or neutral fat) and 3 water molecules.\"><img decoding=\"async\" data-media-type=\"image\/jpeg\" alt=\"A diagram showing a triglyceride is made of a glycerol and three fatty acids. Glycerol is a 3 carbon chain with an OH on each carbon. The H on each OH is highlighted. Fatty acids are long carbon chains with a C that has an OH and a double bonded O at the end. The OH of this C is highlighted. Three fatty acids are shown. Each fatty acid binds to one of the O\u2019s from the OH groups on each Carbon on glycerol. The result is a triglyceride (or neutral fat) and 3 water molecules.\" width=\"1300\" height=\"395\" src=\"https:\/\/openstax.org\/apps\/archive\/20240226.174525\/resources\/4efff70e4be2438a96ad46923a5a9cdbbbf769ef\" \/><\/span><\/figure>\n<div style=\"text-align: center\"><span id=\"output\" class=\"outputbox\"><a href=\"https:\/\/openstax.org\/books\/microbiology\/pages\/7-3-lipids#OSC_Microbio_07_03_trygly\" target=\"_blank\" rel=\"noopener\">&#8220;Triglyceride&#8221;<\/a><span>\u00a0<\/span>by<span>\u00a0<\/span><a>Openstax<\/a><a><\/a><a><\/a><span>\u00a0<\/span>is licensed under<span>\u00a0<\/span><a href=\"http:\/\/creativecommons.org\/licenses\/by\/4.0\" target=\"_blank\" rel=\"noopener\">CC BY 4.0<\/a><a><\/a><\/span><span><\/span><\/div>\n<div class=\"os-caption-container\"><span style=\"font-family: 'Cormorant Garamond', serif;font-size: 1.602em;font-weight: bold\">Phospholipids\u00a0<\/span><\/div>\n<div>These are complex lipids.<\/div>\n<div>These are composed of glycerol esterified with two fatty acids<\/div>\n<div>The third binding position of glycerol is attached with a modified phosphate group.<\/div>\n<\/div>\n<\/section>\n<section id=\"fs-id1167662514925\" data-depth=\"1\">\n<div class=\"os-figure\" id=\"OSC_Microbio_07_03_phospholip\">\n<figure data-id=\"OSC_Microbio_07_03_phospholip\"><span data-type=\"media\" id=\"fs-id1167662615737\" data-alt=\"A drawing of a phospholipid as a large circle with 2 rectangles projecting from the bottom. The circle is labeled hydrophilic head and contains glycerol (which contains 3 carbons). Attached ot one of these carbons is a phosphate (which is a phosphorus attached to 4 oxygen atoms). The rectangles at the bottom are both long carbon chains labeled as hydrophobic tails. One of the chains is a straight zig-zag line and is labeled saturated fatty acid. The other has a double bond that creates a bend in the line; this is labeled unsaturated fatty acid.\"><img decoding=\"async\" data-media-type=\"image\/jpeg\" alt=\"A drawing of a phospholipid as a large circle with 2 rectangles projecting from the bottom. The circle is labeled hydrophilic head and contains glycerol (which contains 3 carbons). Attached ot one of these carbons is a phosphate (which is a phosphorus attached to 4 oxygen atoms). The rectangles at the bottom are both long carbon chains labeled as hydrophobic tails. One of the chains is a straight zig-zag line and is labeled saturated fatty acid. The other has a double bond that creates a bend in the line; this is labeled unsaturated fatty acid.\" width=\"361\" height=\"340\" src=\"https:\/\/openstax.org\/apps\/archive\/20240226.174525\/resources\/1826a2a1ae4622f4c87b06bad15a4cd091ec728d\" class=\"aligncenter\" \/><\/span><\/figure>\n<div style=\"text-align: center\"><span class=\"outputbox\"><a href=\"https:\/\/openstax.org\/books\/microbiology\/pages\/7-3-lipids#OSC_Microbio_07_03_phospholip\" target=\"_blank\" rel=\"noopener\">&#8220;Phospholipids&#8221;<\/a><span>\u00a0<\/span>by<span>\u00a0<\/span><a>Openstax<\/a><a><\/a><a><\/a><span>\u00a0<\/span>is licensed under<span>\u00a0<\/span><a href=\"http:\/\/creativecommons.org\/licenses\/by\/4.0\" target=\"_blank\" rel=\"noopener\">CC BY 4.0<\/a><a><\/a><\/span><span><\/span><\/div>\n<div class=\"os-caption-container\">Unlike other lipids Phospholipids are hydrophilic as they have a negatively charged phosphate group which can attract water.<\/div>\n<\/div>\n<p id=\"fs-id1167662690143\">\u00a0The hydrophilic portion of the phospholipid is often referred to as a polar \u201chead,\u201d and the long hydrocarbon chains as nonpolar \u201ctails.\u201d<\/p>\n<p>As these contain both molecule hydrophobic portion and a hydrophilic moiety, they are said to be<span>\u00a0<\/span><span data-type=\"term\" id=\"term-00023\">amphipathic<\/span>.<\/p>\n<p>This amphipathic nature enables them to form unique functional structures in aqueous environments.<\/p>\n<p>The amphipathic nature of phospholipids enables them to form uniquely functional structures in aqueous environments like<\/p>\n<p><strong>Miscelles<\/strong> : These are spherical assemblies containing a hydrophobic phospholipid tail in the interior and the polar head groups on the outer surface.<\/p>\n<p><strong><span data-type=\"term\" id=\"term-00026\">Lipid-bilayer <\/span>sheets, or <span data-type=\"term\" id=\"term-00027\">unit membranes: <\/span><\/strong><span data-type=\"term\">These<\/span>\u00a0are large, two-dimensional assemblies of<span>\u00a0<\/span><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00028\">phospholipid<\/span>s congregated tail to tail. The cell membranes of cells are made of lipid-bilayer sheets.<\/p>\n<p><strong><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_426_859\">Liposomes:<\/a><\/strong> These are lipid spheres formed by lipid bilayer sheets.<\/p>\n<p>&nbsp;<\/p>\n<p>&nbsp;<\/p>\n<div class=\"os-figure\" id=\"OSC_Microbio_07_03_micelle\">\n<figure data-id=\"OSC_Microbio_07_03_micelle\"><span data-type=\"media\" id=\"fs-id1167662406507\" data-alt=\"A lipid bilayer sheet is when there are 2 rows of phospholipids across each other forming a flat surface. The polar heads of all phospholipids are towards the outside of the sheet, and the nonpolar tails are towards the inside. This lipid-bilyaer can also form a sphere. The lipid-bilayer forms the surface of the sphere; the polar heads are on the outside of the sphere and lining the inside space of the sphere. Lipids can also form a single-layer sphere where the outside of the sphere is the polar heads and the nonpolar tails fill the center of the sphere.\"><img decoding=\"async\" data-media-type=\"image\/jpeg\" alt=\"A lipid bilayer sheet is when there are 2 rows of phospholipids across each other forming a flat surface. The polar heads of all phospholipids are towards the outside of the sheet, and the nonpolar tails are towards the inside. This lipid-bilyaer can also form a sphere. The lipid-bilayer forms the surface of the sphere; the polar heads are on the outside of the sphere and lining the inside space of the sphere. Lipids can also form a single-layer sphere where the outside of the sphere is the polar heads and the nonpolar tails fill the center of the sphere.\" width=\"525\" height=\"236\" src=\"https:\/\/openstax.org\/apps\/archive\/20240226.174525\/resources\/f8689731ee7ce1cf711376fe23dbafbceac4da9f\" class=\"aligncenter\" \/><\/span><\/figure>\n<\/div>\n<div data-type=\"note\" id=\"fs-id1167662487861\" class=\"microbiology check-your-understanding ui-has-child-title\">\n<p style=\"text-align: center\"><a href=\"https:\/\/openstax.org\/books\/microbiology\/pages\/7-3-lipids#OSC_Microbio_07_03_micelle\" target=\"_blank\" rel=\"noopener\">&#8220;Miscelles&#8221;<\/a><span>\u00a0by\u00a0<\/span><a>Openstax<\/a><a><\/a><a><\/a><span>\u00a0is licensed under\u00a0<\/span><a href=\"http:\/\/creativecommons.org\/licenses\/by\/4.0\" target=\"_blank\" rel=\"noopener\">CC BY 4.0<\/a><\/p>\n<header>\n<h2>Glycolipids<\/h2>\n<p><span>A <\/span><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00024\">polar head group<\/span>can be more complex than a simple phosphate moiety. Glycolipids are examples in which carbohydrates are bonded to the lipids\u2019 head groups.<\/p>\n<h2><span>\u00a0I<\/span><span data-type=\"term\" id=\"term-00031\">soprenoids<\/span><\/h2>\n<\/header>\n<\/div>\n<\/section>\n<section id=\"fs-id1167662616038\" data-depth=\"1\">\n<p id=\"fs-id1167662685607\">The<span><\/span><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_426_861\"><span>\u00a0<\/span><span data-type=\"term\">isoprenoids<\/span><\/a><span data-type=\"term\"><\/span><span>\u00a0<\/span>are branched lipids, also referred to as<span>\u00a0<\/span><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00032\">terpenoids<\/span>,<\/p>\n<p>These are formed by chemical modifications of the<span>\u00a0<\/span><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00033\">isoprene<\/span><span>\u00a0<\/span>molecule.<\/p>\n<p>These lipids play a wide variety of physiological roles in plants and animals.<\/p>\n<p>For example, they are constituents of plant pigments like beta carotene, xanthophylls, Fragrances like menthol, camphor.<\/p>\n<p>Long-chain isoprenoids are also found in<span>\u00a0<\/span><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00034\">hydrophobic<\/span><span>\u00a0<\/span>oils and<span>\u00a0<\/span><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00035\">waxes<\/span>.<\/p>\n<p>Waxes are typically water resistant and hard at room temperature, but they soften when heated and liquefy if warmed adequately. The sebaceous glands of hair follicles in the human skin secrete sebum, which consists mainly of triacylglycerol, wax esters, and the hydrocarbon squalene.<\/p>\n<div class=\"os-figure\" id=\"OSC_Microbio_07_03_isoprene\">\n<figure data-id=\"OSC_Microbio_07_03_isoprene\"><span data-type=\"media\" id=\"fs-id1167662489293\" data-alt=\"Alpha-pinene is a carbon ring with added carbon projections. Camphor is a carbon ring with added carbon projections and a double bonded oxygen on one carbon. Isophrene is a 4 carbon chain with another carbon attached to carbon 2. Limonene is a carbon ring with a carbon attached to on one end and another carbon attached to the other end; this carbon has 2 carbons attached to it. Menthol i s a carbon ring with a carbon attached to on one end and another carbon attached to the other end; this carbon has 2 carbons attached to it. One more carbon corner has an OH group. Beta-carotene is two carbon rings attached by a long carbon chain.\"><img decoding=\"async\" data-media-type=\"image\/jpeg\" alt=\"Alpha-pinene is a carbon ring with added carbon projections. Camphor is a carbon ring with added carbon projections and a double bonded oxygen on one carbon. Isophrene is a 4 carbon chain with another carbon attached to carbon 2. Limonene is a carbon ring with a carbon attached to on one end and another carbon attached to the other end; this carbon has 2 carbons attached to it. Menthol i s a carbon ring with a carbon attached to on one end and another carbon attached to the other end; this carbon has 2 carbons attached to it. One more carbon corner has an OH group. Beta-carotene is two carbon rings attached by a long carbon chain.\" width=\"560\" height=\"313\" src=\"https:\/\/openstax.org\/apps\/archive\/20240226.174525\/resources\/6b063f9987ec8eb594496d4b287ec519286f66b5\" class=\"aligncenter\" \/><\/span><\/figure>\n<p style=\"text-align: center\"><a href=\"https:\/\/openstax.org\/books\/microbiology\/pages\/7-3-lipids#OSC_Microbio_07_03_isoprene\" target=\"_blank\" rel=\"noopener\">&#8220;Isoprenoids&#8221;<\/a><span>\u00a0by\u00a0<\/span><a>Openstax<\/a><a><\/a><a><\/a><span>\u00a0is licensed under\u00a0<\/span><a href=\"http:\/\/creativecommons.org\/licenses\/by\/4.0\" target=\"_blank\" rel=\"noopener\">CC BY 4.0<\/a><\/p>\n<div class=\"os-caption-container\"><\/div>\n<div>\n<p><span style=\"font-family: 'Cormorant Garamond', serif;font-size: 1.602em;font-weight: bold\">Steroids, Sterol, Cholesterol<\/span><\/p>\n<p>These are complex ring structure lipids.<\/p>\n<p>They are found in cell membrane.<\/p>\n<p>Some function as hormones example Oestrogen.<\/p>\n<p><span style=\"text-align: initial;font-size: 1em\">\u00a0The most common types of steroids are<\/span><span style=\"text-align: initial;font-size: 1em\">\u00a0<\/span><span data-type=\"term\" id=\"term-00037\" style=\"text-align: initial;font-size: 1em\"><\/span><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_426_863\"><span data-type=\"term\" style=\"text-align: initial;font-size: 1em\">sterol<\/span><strong style=\"text-align: initial;font-size: 1em\">s<\/strong><\/a><span style=\"text-align: initial;font-size: 1em\">, which are steroids containing an OH group. These are mainly<\/span><span style=\"text-align: initial;font-size: 1em\">\u00a0<\/span><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00038\" style=\"text-align: initial;font-size: 1em\">hydrophobic<\/span><span style=\"text-align: initial;font-size: 1em\">\u00a0<\/span><span style=\"text-align: initial;font-size: 1em\">molecules, but also have hydrophilic<\/span><span style=\"text-align: initial;font-size: 1em\">\u00a0<\/span><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00039\" style=\"text-align: initial;font-size: 1em\">hydroxyl group<\/span><span style=\"text-align: initial;font-size: 1em\">s.<\/span><\/p>\n<p><strong>Cholesterol is the most common sterol found in animal tissues.<\/strong><\/p>\n<p><span style=\"text-align: initial;font-size: 1em\">\u00a0Its structure consists of four rings with a double bond in one of the rings, and a hydroxyl group at the sterol-defining position.<\/span><\/p>\n<p>Cholesterol strengthens cell membrane.<\/p>\n<p><span style=\"text-align: initial;font-size: 1em\">\u00a0Prokaryotes generally do not produce cholesterol, although bacteria produce similar compounds called<\/span><span style=\"text-align: initial;font-size: 1em\">\u00a0<\/span><em><strong><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00041\" style=\"text-align: initial;font-size: 1em\"><a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_426_865\">hopanoids<\/a><\/span><\/strong><\/em><span style=\"text-align: initial;font-size: 1em\"><em><strong>,<\/strong><\/em> which are also multiringed structures that strengthen bacterial membranes.<\/span><\/p>\n<p><span style=\"text-align: initial;font-size: 1em\">Fungi and some protozoa produce a similar compound called<\/span><span style=\"text-align: initial;font-size: 1em\">\u00a0<\/span><strong><span data-type=\"term\" class=\"no-emphasis\" id=\"term-00042\" style=\"text-align: initial;font-size: 1em\">ergosterol<\/span><\/strong><span style=\"text-align: initial;font-size: 1em\">, which strengthens the cell membranes of these organisms.<\/span><\/p>\n<\/div>\n<\/div>\n<div class=\"os-figure\" id=\"OSC_Microbio_07_03_sterols\">\n<figure data-id=\"OSC_Microbio_07_03_sterols\"><span data-type=\"media\" id=\"fs-id1167662491684\" data-alt=\"Cholesterol is made of 3 hexagons attached along their edges. The third hexagon has a pentagon attached along an edge. The pentagon has a carbon chain attached to it. Hopene is made of 4 hexagons attached along their edges. The last hexagon has a pentagon. The pentagon has a short carbon chain.\"><img decoding=\"async\" data-media-type=\"image\/jpeg\" alt=\"Cholesterol is made of 3 hexagons attached along their edges. The third hexagon has a pentagon attached along an edge. The pentagon has a carbon chain attached to it. Hopene is made of 4 hexagons attached along their edges. The last hexagon has a pentagon. The pentagon has a short carbon chain.\" width=\"484\" height=\"148\" src=\"https:\/\/openstax.org\/apps\/archive\/20240226.174525\/resources\/f396bb45cb4e2fa96b41d7d43994cd22d4e25cf9\" class=\"aligncenter\" \/><\/span><\/figure>\n<p style=\"text-align: center\"><a href=\"https:\/\/openstax.org\/books\/microbiology\/pages\/7-3-lipids#OSC_Microbio_07_03_sterols\" target=\"_blank\" rel=\"noopener\">Sterols&#8221;<\/a><span>\u00a0by\u00a0<\/span><a>Openstax<\/a><span>\u00a0is licensed under\u00a0<\/span><a href=\"http:\/\/creativecommons.org\/licenses\/by\/4.0\" target=\"_blank\" rel=\"noopener\">CC BY 4.0<\/a><\/p>\n<\/div>\n<h2>Test your Understanding<\/h2>\n<p><span><\/p>\n<div id=\"h5p-110\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-110\" class=\"h5p-iframe\" data-content-id=\"110\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"macromolecule structure vs function\"><\/iframe><\/div>\n<\/div>\n<p><\/span><\/p>\n<\/section>\n<div class=\"glossary\"><span class=\"screen-reader-text\" id=\"definition\">definition<\/span><template id=\"term_426_859\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_426_859\"><div tabindex=\"-1\"><p>Lipid spheres made of bilayer sheets<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_426_861\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_426_861\"><div tabindex=\"-1\"><p>Branched lipids also known as terpenoids<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_426_863\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_426_863\"><div tabindex=\"-1\"><p>Most common type of steroids<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_426_865\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_426_865\"><div tabindex=\"-1\"><p>Compounds similar to cholesterol produced by bacteria<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><\/div>","protected":false},"author":5,"menu_order":10,"template":"","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"_uf_show_specific_survey":0,"_uf_disable_surveys":false,"pb_show_title":"on","pb_short_title":"Molecules of the cell -Lipids","pb_subtitle":"Molecules of the cell","pb_authors":["malathi","sushumna"],"pb_section_license":"cc-by-sa"},"chapter-type":[],"contributor":[62,66],"license":[54],"class_list":["post-426","chapter","type-chapter","status-publish","hentry","contributor-malathi","contributor-sushumna","license-cc-by-sa"],"aioseo_notices":[],"part":3,"_links":{"self":[{"href":"https:\/\/pressbooks.justwrite.in\/interactive-biology-secondary\/wp-json\/pressbooks\/v2\/chapters\/426","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.justwrite.in\/interactive-biology-secondary\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.justwrite.in\/interactive-biology-secondary\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.justwrite.in\/interactive-biology-secondary\/wp-json\/wp\/v2\/users\/5"}],"version-history":[{"count":29,"href":"https:\/\/pressbooks.justwrite.in\/interactive-biology-secondary\/wp-json\/pressbooks\/v2\/chapters\/426\/revisions"}],"predecessor-version":[{"id":2058,"href":"https:\/\/pressbooks.justwrite.in\/interactive-biology-secondary\/wp-json\/pressbooks\/v2\/chapters\/426\/revisions\/2058"}],"part":[{"href":"https:\/\/pressbooks.justwrite.in\/interactive-biology-secondary\/wp-json\/pressbooks\/v2\/parts\/3"}],"metadata":[{"href":"https:\/\/pressbooks.justwrite.in\/interactive-biology-secondary\/wp-json\/pressbooks\/v2\/chapters\/426\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.justwrite.in\/interactive-biology-secondary\/wp-json\/wp\/v2\/media?parent=426"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.justwrite.in\/interactive-biology-secondary\/wp-json\/pressbooks\/v2\/chapter-type?post=426"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.justwrite.in\/interactive-biology-secondary\/wp-json\/wp\/v2\/contributor?post=426"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.justwrite.in\/interactive-biology-secondary\/wp-json\/wp\/v2\/license?post=426"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}