{"id":1248,"date":"2019-07-26T19:05:03","date_gmt":"2019-07-26T23:05:03","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/chapter\/unit-2-the-chemistry-of-water\/"},"modified":"2025-09-29T13:11:13","modified_gmt":"2025-09-29T17:11:13","slug":"unit-2-the-chemistry-of-water","status":"publish","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/chapter\/unit-2-the-chemistry-of-water\/","title":{"raw":"Unit 2: The Chemistry of Water","rendered":"Unit 2: The Chemistry of Water"},"content":{"raw":"<div class=\"unit-2:-the-chemistry-of-water\">\r\n<div class=\"textbox shaded\">\r\n\r\n<strong>Unit outline<\/strong>\r\n\r\n<a href=\"#2.1\"><strong>Part 1.<\/strong> Biological importance of water<\/a>\r\n<ul>\r\n \t<li><a href=\"#2.1a\">Water as a Lubricant and Cushion<\/a><\/li>\r\n \t<li><a href=\"http:\/\/2.1b\">Water as a Heat Sink<\/a><\/li>\r\n \t<li><a href=\"#2.1c\">Water as a Component of Liquid Mixtures<\/a><\/li>\r\n \t<li><a href=\"#2.1d\">The Role of Water in Chemical Reactions<\/a><\/li>\r\n<\/ul>\r\n<a href=\"#2.2\"><strong>Part 2.<\/strong> Fluid compartments in the human body<\/a>\r\n<ul>\r\n \t<li><a href=\"#2.2a\">Body Water Content<\/a><\/li>\r\n \t<li><a href=\"#2.2b\">Fluid Compartments<\/a>\r\n<ul>\r\n \t<li>Intracellular Fluid<\/li>\r\n \t<li>Extracellular Fluid<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<h2><a href=\"#P\">Practice Questions<\/a><\/h2>\r\n<\/div>\r\n<div class=\"textbox textbox--learning-objectives\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\"><strong>Learning Objectives<\/strong><\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n\r\nAt the end of this unit, you should be able to:\r\n<p class=\"hanging-indent\"><strong>I. <\/strong>Explain the biological importance of water.<\/p>\r\n<p class=\"hanging-indent\"><strong>II<\/strong><strong>. <\/strong>Specify the percentage of body weight that is composed of water and estimate the amount of body water you contain in litres.<\/p>\r\n<p class=\"hanging-indent\"><strong>III<\/strong><strong>. <\/strong>Describe the distribution of body water.<\/p>\r\n\r\n<\/div>\r\n<\/div>\r\n<div class=\"textbox textbox--learning-objectives\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\"><strong>Learning Objectives and Guiding Questions<\/strong><\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n\r\nAt the end of this unit, you should be able to complete all the following tasks, including answering the guiding questions associated with each task.\r\n<p class=\"hanging-indent\"><strong>I. <\/strong>Explain the biological importance of water.<\/p>\r\n\r\n<ol>\r\n \t<li>For each of the four biologically important properties of water:\r\n<ul>\r\n \t<li>Identify the property.<\/li>\r\n \t<li>Describe its importance in the human body.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ol>\r\n<p class=\"hanging-indent\"><strong>II<\/strong><strong>. <\/strong>Specify the percentage of body weight that is composed of water and estimate the amount of body water you contain in litres.<\/p>\r\n\r\n<ol>\r\n \t<li>Given your (approximate) body weight, calculate the amount of water you contain, in litres. <em>You may use a calculator if necessary, but <\/em><em>must<\/em><em> clearly show all your work!<\/em><\/li>\r\n<\/ol>\r\n<p class=\"hanging-indent\"><strong>III<\/strong><strong>. <\/strong>Describe the distribution of body water.<\/p>\r\n\r\n<ol>\r\n \t<li>For each of the major fluid compartments of the human body:\r\n<ul>\r\n \t<li>Name the compartment.<\/li>\r\n \t<li>Define the compartment by specifying its location in the human body.<\/li>\r\n \t<li>Specify the percentage of body fluid volume made up by that compartment.<\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ol>\r\n<\/div>\r\n<\/div>\r\n&nbsp;\r\n<p style=\"text-align: justify\">As much as 70 percent of a human\u2019s body weight is water. This water is contained both within the cells and between the cells that make up tissues and organs. Its several roles make water indispensable to human functioning.<\/p>\r\n\r\n<h2 style=\"text-align: justify\"><strong>Part 1. Biological Importance of Water<\/strong><\/h2>\r\n<h5 style=\"text-align: justify\"><strong>Water as a Lubricant and Cushion<\/strong><\/h5>\r\n<p style=\"text-align: justify\">Water is a major component of many of the body\u2019s lubricating fluids. Just as oil lubricates the hinge on a door, water in [pb_glossary id=\"2107\"]synovial fluid[\/pb_glossary] lubricates the actions of body joints, and water in [pb_glossary id=\"2108\"]pleural fluid[\/pb_glossary] helps the lungs expand and recoil with breathing. Watery fluids help keep food flowing through the digestive tract, and ensure that the movement of adjacent abdominal organs is friction free.<\/p>\r\n<p style=\"text-align: justify\">Water also protects cells and organs from physical trauma, cushioning the brain within the skull, for example, and protecting the delicate nerve tissue of the eyes. Water cushions a developing fetus in the mother\u2019s womb as well.<\/p>\r\n\r\n<h5 style=\"text-align: justify\"><strong>Water as a Heat Sink<\/strong><\/h5>\r\n<p style=\"text-align: justify\">A heat sink is a substance or object that absorbs and [pb_glossary id=\"2109\"]dissipates[\/pb_glossary] heat but does not experience a corresponding increase in temperature. In the body, water absorbs the heat generated by chemical reactions without greatly increasing in temperature. Moreover, when environmental temperature soars, the water stored in the body helps keep the body cool. This cooling effect happens as warm blood from the body\u2019s core flows to the blood vessels just under the skin and is transferred out to the environment as radiant heat. At the same time, sweat glands release warm water in sweat. For evaporation of this water to occur, the [pb_glossary id=\"2103\"]hydrogen bonds[\/pb_glossary] between the water molecules must be broken, requiring a relatively high amount of energy that in part includes heat. This removal of heat by evaporation results in a cooling of the blood in the body\u2019s periphery, near the surface of the skin, which then circulates back to the body core and cools the body.<\/p>\r\n\r\n<h5 style=\"text-align: justify\"><strong>Water as a Component of Liquid Mixtures<\/strong><\/h5>\r\n<p style=\"text-align: justify\">A mixture is a combination of two or more substances, each of which maintains its own chemical identity. In other words, the constituent substances are not chemically bonded into a new, larger chemical [pb_glossary id=\"2063\"]compound[\/pb_glossary]. The concept is easy to imagine if you think of powdery substances such as flour and sugar; when you stir them together in a bowl, they obviously do not bond to form a new compound. The room air you breathe is a gaseous mixture, containing argon, molecules of nitrogen and oxygen, and one compound\u2014 carbon dioxide.<\/p>\r\n<p style=\"text-align: justify\">For cells in the body to survive, they must be kept moist in a water-based liquid called a<strong> [pb_glossary id=\"2110\"]solution[\/pb_glossary]<\/strong>. In chemistry, a liquid solution consists of a [pb_glossary id=\"2111\"]solvent[\/pb_glossary] that dissolves a substance called a [pb_glossary id=\"2112\"]solute[\/pb_glossary]. An important characteristic of solutions is that they are [pb_glossary id=\"2113\"]homogeneous[\/pb_glossary]; that is, the solute molecules are distributed evenly throughout the solution. If you were to stir a teaspoon of sugar into a glass of water, the sugar would dissolve into sugar molecules separated by water molecules. The ratio of sugar to water in the left side of the glass would be the same as the ratio of sugar to water in the right side of the glass. If you were to add more sugar, the ratio of sugar to water would change, but the distribution\u2014provided you had stirred well\u2014would still be even.<\/p>\r\n\r\n<h5 style=\"text-align: justify\"><strong>The Role of Water in Chemical Reactions<\/strong><\/h5>\r\n<p style=\"text-align: justify\">Two types of chemical reactions involve the creation or the consumption of water: dehydration synthesis and hydrolysis.<\/p>\r\n\r\n<ul>\r\n \t<li>In [pb_glossary id=\"2114\"]dehydration synthesis[\/pb_glossary], one reactant gives up an atom of hydrogen and another reactant gives up a [pb_glossary id=\"2125\"]hydroxyl[\/pb_glossary] group (OH) in the synthesis of a new product. In the formation of their covalent bond, a molecule of water is released as a byproduct (Figure 1). This is also sometimes referred to as a condensation reaction.<\/li>\r\n \t<li>In [pb_glossary id=\"2115\"]hydrolysis[\/pb_glossary], a molecule of water disrupts a compound, breaking its bonds. The water is itself split into H and OH. One portion of the severed compound then bonds with the hydrogen atom, and the other portion bonds with the hydroxyl group.<\/li>\r\n<\/ul>\r\n<p style=\"text-align: justify\">These reactions are reversible, and play an important role in the chemistry of organic compounds (which will be discussed shortly).<\/p>\r\n\r\n\r\n[caption id=\"\" align=\"alignnone\" width=\"1667\"]<img src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image1-2.png\" alt=\"image\" width=\"1667\" height=\"858\" \/> <strong>Figure 1. Dehydration Synthesis and Hydrolysis.\u00a0 <\/strong>Monomers, the basic units for building larger molecules, form polymers (two or more chemically-bonded monomers). (a) In dehydration synthesis, two monomers are covalently bonded in a reaction in which one gives up a hydroxyl group and the other a hydrogen atom. A molecule of water is released as a byproduct during dehydration reactions. (b) In hydrolysis, the covalent bond between two monomers is split by the addition of a hydrogen atom to one and a hydroxyl group to the other, which requires the contribution of one molecule of water.[\/caption]\r\n<h2><strong>Part 2. Fluid Compartments in the Human Body<\/strong><\/h2>\r\n<h5 style=\"text-align: justify\"><strong>Body Water Content<\/strong><\/h5>\r\n<p style=\"text-align: justify\">Human beings are mostly water, ranging from about 75 percent of body mass in infants to as low as 45 percent in old age. In adults, the average percent of body mass in women is 50 percent, whereas in men the average is 60 percent. The percent of body water changes with development, because the proportions of the body given over to each organ and to muscles, fat, bone, and other tissues change from infancy to adulthood (Figure 2).<\/p>\r\n\r\n<\/div>\r\n<strong style=\"font-size: 1.125em;text-align: justify\">Fluid Compartments<\/strong>\r\n<div class=\"unit-2:-the-chemistry-of-water\">\r\n<p style=\"text-align: justify\">Body fluids can be discussed in terms of their specific fluid compartment, a location that is largely separate from another compartment by some form of a physical barrier. The [pb_glossary id=\"2126\"]intracellular fluid\u00a0(ICF)[\/pb_glossary] compartment is the system that includes all fluid enclosed in cells by their plasma membranes. [pb_glossary id=\"2127\"]Extracellular fluid (ECF)[\/pb_glossary] surrounds all cells in the body. Extracellular fluid has two primary constituents: the fluid component of the blood (called [pb_glossary id=\"2128\"]plasma[\/pb_glossary]) and the [pb_glossary id=\"2129\"]interstitial fluid (IF)[\/pb_glossary] that surrounds all cells not in the blood (Figure 3).<\/p>\r\n<p style=\"text-align: justify\"><strong>1. [pb_glossary id=\"2126\"]Intracellular Fluid[\/pb_glossary]:<\/strong> The intracellular fluid lies within cells and is the principal component of the [pb_glossary id=\"2130\"]cytosol[\/pb_glossary]\/[pb_glossary id=\"2131\"]cytoplasm[\/pb_glossary]. The intracellular fluid makes up more than half, about 66%,\u00a0 of the total water in the human body, accounting for about 20 litres in an average adult human (Figure 4). This fluid volume tends to be very stable, because the amount of water in living cells is closely regulated. If the amount of water inside a cell falls to a value that is too low, the cytosol becomes too concentrated with solutes to carry on normal cellular activities; if too much water enters a cell, the cell may burst and be destroyed.<\/p>\r\n<p style=\"text-align: justify\"><strong>2. [pb_glossary id=\"2127\"]Extracellular Fluid[\/pb_glossary]:<\/strong> The extracellular fluid accounts for the remainder of the body\u2019s water content. Approximately 16% of the extracellular fluid is found in [pb_glossary id=\"2128\"]plasma[\/pb_glossary]. Plasma travels through the body in blood vessels and transports a range of materials, including blood cells, proteins (including [pb_glossary id=\"2132\"]clotting factors[\/pb_glossary] and [pb_glossary id=\"2133\"]antibodies[\/pb_glossary]), [pb_glossary id=\"2134\"]electrolytes[\/pb_glossary], nutrients, gases, and wastes. Gases, nutrients, and waste materials travel between [pb_glossary id=\"2135\"]capillaries[\/pb_glossary] and cells through the [pb_glossary id=\"2129\"]interstitial fluid[\/pb_glossary]. Interstitial fluid is the fluid surrounding living cells in every tissue, and accounts for nearly 80% of the extracellular fluid. Cells are separated from the interstitial fluid by a [pb_glossary id=\"2136\"]selectively permeable[\/pb_glossary] cell membrane that helps regulate the passage of materials between the interstitial fluid and the interior of the cell.<\/p>\r\n<p style=\"text-align: justify\">The body has other water-based extracellular fluid. These include the [pb_glossary id=\"2137\"]cerebrospinal fluid[\/pb_glossary] that bathes the brain and spinal cord, [pb_glossary id=\"2138\"]lymph[\/pb_glossary], the synovial fluid in joints, the [pb_glossary id=\"2108\"]pleural fluid[\/pb_glossary] in the [pb_glossary id=\"2139\"]pleural cavities[\/pb_glossary], the [pb_glossary id=\"2141\"]pericardial fluid[\/pb_glossary] in the [pb_glossary id=\"2140\"]cardiac sac[\/pb_glossary], the peritoneal fluid in the peritoneal cavity, and the aqueous humor of the eye. Because these fluids are outside cells, these fluids are also considered components of the extracellular fluid compartment.<\/p>\r\n\r\n\r\n[caption id=\"attachment_1749\" align=\"alignnone\" width=\"723\"]<img class=\"wp-image-1749 size-large\" src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/2701_Water_Content_in_the_Body-01-fixed-blood-723x1024.png\" alt=\"\" width=\"723\" height=\"1024\" \/> <strong>Figure 2. Water Content of the Body\u2019s Organs and Tissues.<\/strong> Water content varies in different body organs and tissues, from as little as 8 percent in the teeth to as much as 85 percent in the brain.[\/caption]\r\n\r\n[caption id=\"\" align=\"alignnone\" width=\"668\"]<img src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image3-2.png\" alt=\"image\" width=\"668\" height=\"449\" \/> <strong>Figure 3. Fluid Compartments in the Human Body.<\/strong> The intracellular fluid (ICF) is the fluid within cells. The interstitial fluid (IF) is part of the extracellular fluid (ECF) between the cells. Blood plasma is the second part of the extracellular fluid. Materials travel between cells and the plasma in capillaries through the interstitial fluid.[\/caption]\r\n\r\n[caption id=\"\" align=\"alignnone\" width=\"587\"]<img src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image4-2.png\" alt=\"image\" width=\"587\" height=\"489\" \/> <strong>Figure 4. Proportions of Total Body Fluid in Each of the Body\u2019s Fluid Compartments.<\/strong> Most of the water in the body is intracellular fluid. The second largest volume is the interstitial fluid, which surrounds cells that are not blood cells.[\/caption]\r\n\r\n<\/div>\r\n<strong style=\"font-size: 1.125em;text-align: justify\">Calculation of the percentage body water<\/strong>\r\n\r\nTotal body water (TBW) is calculated by multiplying 0.6 times your weight in kilograms for males or 0.5 times your weight for females, as follows:\r\n\r\nMale: Body weight (kg) x 0.6= TBW (L)\r\n\r\nFemale: Body weight (kg) x 0.5= TBW (L)\r\n\r\nTo determine the percentage body water, it is assumed that 1 litre equals 1 kilogram. The average proportions of water present across various compartments of the body are shown in Figure 5.\r\n\r\n[caption id=\"attachment_3269\" align=\"alignnone\" width=\"993\"]<a href=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/Picture1.png\"><img class=\"wp-image-3269 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/Picture1.png\" alt=\"Diagram depicts a human silouette indicating that 60% of total body weight is water. Of that portion, 66.6% is intracellular fluid and 33.3% is extracellular fluid, which is 80% interstitial fluid and 20% plasma.\" width=\"993\" height=\"495\" \/><\/a> Figure 5. Average proportions of water present across various compartments of the body. Adapted from https:\/\/nursekey.com\/physiological-changes\/[\/caption]\r\n\r\nIntracellular fluid volume cannot be measured directly, but it can be calculated from TBW. On average, two thirds (or 66.6%) of the TBW is intracellular, so we calculate two thirds times (or 0.66x) TBW and find a value expressed in litres.\r\n\r\nTBW x 2\/3= Intracellular fluid volume (L)\r\n\r\nOr\r\n\r\nTBW x 0.66= Intracellular fluid (L)\r\n\r\n&nbsp;\r\n\r\nExtracellular fluid (ECF) can be further broken down into interstitial fluid and blood plasma. Four fifths (or 80%) of the extracellular fluid is composed of interstitial fluid, which is the tissue fluid. The remaining one fifth (or 20%) of the ECF is composed of blood plasma, which is the circulating fluid within blood vessels. The volume of each of these fluid types can be calculated from TBW by first determining the total volume of ECF (one third or 33.3%) and then using that value to determine the volume of interstitial fluid or blood plasma.\r\n\r\nTBW (L) x 1\/3= Extracellular fluid volume (L)\r\n\r\nOr\r\n\r\nTBW (L) \u00a0x 0.33= Extracellular fluid (L)\r\n\r\nLet's look at two different examples, starting with a female who weighs 50 kilograms. The detailed calculations appear below. As the individual is female, we multiply her body weight by 0.5 to determine TBW, which is 25 litres. Two thirds (66.6%) of the TBW is intracellular. Therefore, we calculate two thirds times (0.66x) 25 litres, which is16.5 litres. One third (33.3%) of TBW is extracellular, so 1\/3 (0.33 x) \u00a025 litres is approximately 8.25 litres. Interstitial fluid accounts for 80% of this extracellular fluid. Thus, four fifths (0.8) times 8.25 litres of interstitial fluid is 6.6 litres, and the remaining 1.65 litres are blood plasma.\r\n\r\n50 kg x 0.5= 25 L (TBW)\r\n\r\n25 L x 2\/3= 16.5 L (ICF) \u00a0\u00a0or\u00a0 25 x 0.66= 16.5 L (ICF)\r\n\r\n25 L x 1\/3=8.25 L (ECF)\u00a0 or\u00a0\u00a0 25 x 0.33= 8.25 L (ECF)\r\n\r\n8.25 L x 4\/5= 6.6 L (interstitial fluid)\u00a0 or\u00a0 8.25 x 0.8= 6.6 L (interstitial fluid)\r\n\r\n8.25 L x 1\/5= 1.65 L (plasma)\u00a0 or\u00a0 8.25 x 0.2 = 1.65 L (plasma)\r\n\r\nNow let us consider a male who weighs 75 kilograms. In this case, we multiply his body weight by 0.6. This gives us a TBW of 45 litres. Two thirds (0.66x) 45 litres gives 29.7 litres of intracellular fluid. One third times (0.33x) 45 litres gives 14.85 litres of extracellular fluid. Of these 14.85 litres, interstitial fluid makes up 11.8 litres and blood plasma makes up 2.97 litres.\r\n\r\n75 kg x 0.6= 45 L (TBW)\r\n\r\n45 L x 2\/3= 29.7 L (ICF) \u00a0\u00a0\u00a0\u00a0\u00a0or \u00a0\u00a0\u00a0\u00a045 L x 0.66= 29.7 L (ICF)\r\n\r\n45 L x 1\/3=14.85 L (ECF)\u00a0\u00a0 \u00a0or \u00a0\u00a0\u00a0\u00a045 L x 0.33= 14.85 L (ECF)\r\n\r\n14.85 L x 4\/5= 11.9 L\u00a0\u00a0\u00a0 (interstitial fluid) or 14.85 L x 0.8= 11.9 L (interstitial fluid)\r\n\r\n14.85 L x 1\/5= 2.97 L (plasma)\u00a0 \u00a0or \u00a0\u00a014.85L \u00a0x 0.2 = 2.97 L (plasma)\r\n\r\n<img style=\"color: #373d3f;font-weight: bold;font-size: 1em\" src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image5-2.png\" alt=\"image\" width=\"146\" height=\"142\" \/>\r\n<div class=\"unit-2:-the-chemistry-of-water\">\r\n\r\nWatch <a href=\"https:\/\/youtu.be\/3jwAGWky98c\">this Amoeba Sisters\u2019 video<\/a> to learn more about the properties of water! Direct link:\u00a0<a href=\"https:\/\/youtu.be\/3jwAGWky98c\">https:\/\/youtu.be\/3jwAGWky98c<\/a>\r\n\r\n[caption id=\"\" align=\"alignnone\" width=\"146\"]<img src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image6-2.png\" alt=\"image\" width=\"146\" height=\"146\" \/> Watch <a href=\"https:\/\/youtu.be\/HVT3Y3_gHGg\">this CrashCourse video<\/a> to learn more about the importance of water and its chemical properties. Direct link:\u00a0<a href=\"https:\/\/youtu.be\/HVT3Y3_gHGg\">https:\/\/youtu.be\/HVT3Y3_gHGg<\/a>[\/caption]\r\n\r\n<div class=\"textbox textbox--exercises\"><header class=\"textbox__header\">\r\n<p class=\"textbox__title\">Practice Questions<\/p>\r\n\r\n<\/header>\r\n<div class=\"textbox__content\">\r\n\r\n<strong>Part 1.<\/strong> <strong>Biological importance of water<\/strong>\r\n\r\n[h5p id=\"102\"]\r\n\r\n[h5p id=\"103\"]\r\n\r\n<strong>Part 2.<\/strong> <strong>Fluid compartments in the human body<\/strong>\r\n\r\n[h5p id=\"101\"]\r\n\r\n<\/div>\r\n<\/div>\r\n&nbsp;\r\n\r\n<\/div>","rendered":"<div class=\"unit-2:-the-chemistry-of-water\">\n<div class=\"textbox shaded\">\n<p><strong>Unit outline<\/strong><\/p>\n<p><a href=\"#2.1\"><strong>Part 1.<\/strong> Biological importance of water<\/a><\/p>\n<ul>\n<li><a href=\"#2.1a\">Water as a Lubricant and Cushion<\/a><\/li>\n<li><a href=\"http:\/\/2.1b\">Water as a Heat Sink<\/a><\/li>\n<li><a href=\"#2.1c\">Water as a Component of Liquid Mixtures<\/a><\/li>\n<li><a href=\"#2.1d\">The Role of Water in Chemical Reactions<\/a><\/li>\n<\/ul>\n<p><a href=\"#2.2\"><strong>Part 2.<\/strong> Fluid compartments in the human body<\/a><\/p>\n<ul>\n<li><a href=\"#2.2a\">Body Water Content<\/a><\/li>\n<li><a href=\"#2.2b\">Fluid Compartments<\/a>\n<ul>\n<li>Intracellular Fluid<\/li>\n<li>Extracellular Fluid<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<h2><a href=\"#P\">Practice Questions<\/a><\/h2>\n<\/div>\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\"><strong>Learning Objectives<\/strong><\/p>\n<\/header>\n<div class=\"textbox__content\">\n<p>At the end of this unit, you should be able to:<\/p>\n<p class=\"hanging-indent\"><strong>I. <\/strong>Explain the biological importance of water.<\/p>\n<p class=\"hanging-indent\"><strong>II<\/strong><strong>. <\/strong>Specify the percentage of body weight that is composed of water and estimate the amount of body water you contain in litres.<\/p>\n<p class=\"hanging-indent\"><strong>III<\/strong><strong>. <\/strong>Describe the distribution of body water.<\/p>\n<\/div>\n<\/div>\n<div class=\"textbox textbox--learning-objectives\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\"><strong>Learning Objectives and Guiding Questions<\/strong><\/p>\n<\/header>\n<div class=\"textbox__content\">\n<p>At the end of this unit, you should be able to complete all the following tasks, including answering the guiding questions associated with each task.<\/p>\n<p class=\"hanging-indent\"><strong>I. <\/strong>Explain the biological importance of water.<\/p>\n<ol>\n<li>For each of the four biologically important properties of water:\n<ul>\n<li>Identify the property.<\/li>\n<li>Describe its importance in the human body.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<p class=\"hanging-indent\"><strong>II<\/strong><strong>. <\/strong>Specify the percentage of body weight that is composed of water and estimate the amount of body water you contain in litres.<\/p>\n<ol>\n<li>Given your (approximate) body weight, calculate the amount of water you contain, in litres. <em>You may use a calculator if necessary, but <\/em><em>must<\/em><em> clearly show all your work!<\/em><\/li>\n<\/ol>\n<p class=\"hanging-indent\"><strong>III<\/strong><strong>. <\/strong>Describe the distribution of body water.<\/p>\n<ol>\n<li>For each of the major fluid compartments of the human body:\n<ul>\n<li>Name the compartment.<\/li>\n<li>Define the compartment by specifying its location in the human body.<\/li>\n<li>Specify the percentage of body fluid volume made up by that compartment.<\/li>\n<\/ul>\n<\/li>\n<\/ol>\n<\/div>\n<\/div>\n<p>&nbsp;<\/p>\n<p style=\"text-align: justify\">As much as 70 percent of a human\u2019s body weight is water. This water is contained both within the cells and between the cells that make up tissues and organs. Its several roles make water indispensable to human functioning.<\/p>\n<h2 style=\"text-align: justify\"><strong>Part 1. Biological Importance of Water<\/strong><\/h2>\n<h5 style=\"text-align: justify\"><strong>Water as a Lubricant and Cushion<\/strong><\/h5>\n<p style=\"text-align: justify\">Water is a major component of many of the body\u2019s lubricating fluids. Just as oil lubricates the hinge on a door, water in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2107\">synovial fluid<\/a> lubricates the actions of body joints, and water in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2108\">pleural fluid<\/a> helps the lungs expand and recoil with breathing. Watery fluids help keep food flowing through the digestive tract, and ensure that the movement of adjacent abdominal organs is friction free.<\/p>\n<p style=\"text-align: justify\">Water also protects cells and organs from physical trauma, cushioning the brain within the skull, for example, and protecting the delicate nerve tissue of the eyes. Water cushions a developing fetus in the mother\u2019s womb as well.<\/p>\n<h5 style=\"text-align: justify\"><strong>Water as a Heat Sink<\/strong><\/h5>\n<p style=\"text-align: justify\">A heat sink is a substance or object that absorbs and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2109\">dissipates<\/a> heat but does not experience a corresponding increase in temperature. In the body, water absorbs the heat generated by chemical reactions without greatly increasing in temperature. Moreover, when environmental temperature soars, the water stored in the body helps keep the body cool. This cooling effect happens as warm blood from the body\u2019s core flows to the blood vessels just under the skin and is transferred out to the environment as radiant heat. At the same time, sweat glands release warm water in sweat. For evaporation of this water to occur, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2103\">hydrogen bonds<\/a> between the water molecules must be broken, requiring a relatively high amount of energy that in part includes heat. This removal of heat by evaporation results in a cooling of the blood in the body\u2019s periphery, near the surface of the skin, which then circulates back to the body core and cools the body.<\/p>\n<h5 style=\"text-align: justify\"><strong>Water as a Component of Liquid Mixtures<\/strong><\/h5>\n<p style=\"text-align: justify\">A mixture is a combination of two or more substances, each of which maintains its own chemical identity. In other words, the constituent substances are not chemically bonded into a new, larger chemical <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2063\">compound<\/a>. The concept is easy to imagine if you think of powdery substances such as flour and sugar; when you stir them together in a bowl, they obviously do not bond to form a new compound. The room air you breathe is a gaseous mixture, containing argon, molecules of nitrogen and oxygen, and one compound\u2014 carbon dioxide.<\/p>\n<p style=\"text-align: justify\">For cells in the body to survive, they must be kept moist in a water-based liquid called a<strong> <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2110\">solution<\/a><\/strong>. In chemistry, a liquid solution consists of a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2111\">solvent<\/a> that dissolves a substance called a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2112\">solute<\/a>. An important characteristic of solutions is that they are <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2113\">homogeneous<\/a>; that is, the solute molecules are distributed evenly throughout the solution. If you were to stir a teaspoon of sugar into a glass of water, the sugar would dissolve into sugar molecules separated by water molecules. The ratio of sugar to water in the left side of the glass would be the same as the ratio of sugar to water in the right side of the glass. If you were to add more sugar, the ratio of sugar to water would change, but the distribution\u2014provided you had stirred well\u2014would still be even.<\/p>\n<h5 style=\"text-align: justify\"><strong>The Role of Water in Chemical Reactions<\/strong><\/h5>\n<p style=\"text-align: justify\">Two types of chemical reactions involve the creation or the consumption of water: dehydration synthesis and hydrolysis.<\/p>\n<ul>\n<li>In <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2114\">dehydration synthesis<\/a>, one reactant gives up an atom of hydrogen and another reactant gives up a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2125\">hydroxyl<\/a> group (OH) in the synthesis of a new product. In the formation of their covalent bond, a molecule of water is released as a byproduct (Figure 1). This is also sometimes referred to as a condensation reaction.<\/li>\n<li>In <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2115\">hydrolysis<\/a>, a molecule of water disrupts a compound, breaking its bonds. The water is itself split into H and OH. One portion of the severed compound then bonds with the hydrogen atom, and the other portion bonds with the hydroxyl group.<\/li>\n<\/ul>\n<p style=\"text-align: justify\">These reactions are reversible, and play an important role in the chemistry of organic compounds (which will be discussed shortly).<\/p>\n<figure style=\"width: 1667px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image1-2.png\" alt=\"image\" width=\"1667\" height=\"858\" \/><figcaption class=\"wp-caption-text\"><strong>Figure 1. Dehydration Synthesis and Hydrolysis.\u00a0 <\/strong>Monomers, the basic units for building larger molecules, form polymers (two or more chemically-bonded monomers). (a) In dehydration synthesis, two monomers are covalently bonded in a reaction in which one gives up a hydroxyl group and the other a hydrogen atom. A molecule of water is released as a byproduct during dehydration reactions. (b) In hydrolysis, the covalent bond between two monomers is split by the addition of a hydrogen atom to one and a hydroxyl group to the other, which requires the contribution of one molecule of water.<\/figcaption><\/figure>\n<h2><strong>Part 2. Fluid Compartments in the Human Body<\/strong><\/h2>\n<h5 style=\"text-align: justify\"><strong>Body Water Content<\/strong><\/h5>\n<p style=\"text-align: justify\">Human beings are mostly water, ranging from about 75 percent of body mass in infants to as low as 45 percent in old age. In adults, the average percent of body mass in women is 50 percent, whereas in men the average is 60 percent. The percent of body water changes with development, because the proportions of the body given over to each organ and to muscles, fat, bone, and other tissues change from infancy to adulthood (Figure 2).<\/p>\n<\/div>\n<p><strong style=\"font-size: 1.125em;text-align: justify\">Fluid Compartments<\/strong><\/p>\n<div class=\"unit-2:-the-chemistry-of-water\">\n<p style=\"text-align: justify\">Body fluids can be discussed in terms of their specific fluid compartment, a location that is largely separate from another compartment by some form of a physical barrier. The <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2126\">intracellular fluid\u00a0(ICF)<\/a> compartment is the system that includes all fluid enclosed in cells by their plasma membranes. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2127\">Extracellular fluid (ECF)<\/a> surrounds all cells in the body. Extracellular fluid has two primary constituents: the fluid component of the blood (called <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2128\">plasma<\/a>) and the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2129\">interstitial fluid (IF)<\/a> that surrounds all cells not in the blood (Figure 3).<\/p>\n<p style=\"text-align: justify\"><strong>1. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2126\">Intracellular Fluid<\/a>:<\/strong> The intracellular fluid lies within cells and is the principal component of the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2130\">cytosol<\/a>\/<a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2131\">cytoplasm<\/a>. The intracellular fluid makes up more than half, about 66%,\u00a0 of the total water in the human body, accounting for about 20 litres in an average adult human (Figure 4). This fluid volume tends to be very stable, because the amount of water in living cells is closely regulated. If the amount of water inside a cell falls to a value that is too low, the cytosol becomes too concentrated with solutes to carry on normal cellular activities; if too much water enters a cell, the cell may burst and be destroyed.<\/p>\n<p style=\"text-align: justify\"><strong>2. <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2127\">Extracellular Fluid<\/a>:<\/strong> The extracellular fluid accounts for the remainder of the body\u2019s water content. Approximately 16% of the extracellular fluid is found in <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2128\">plasma<\/a>. Plasma travels through the body in blood vessels and transports a range of materials, including blood cells, proteins (including <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2132\">clotting factors<\/a> and <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2133\">antibodies<\/a>), <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2134\">electrolytes<\/a>, nutrients, gases, and wastes. Gases, nutrients, and waste materials travel between <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2135\">capillaries<\/a> and cells through the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2129\">interstitial fluid<\/a>. Interstitial fluid is the fluid surrounding living cells in every tissue, and accounts for nearly 80% of the extracellular fluid. Cells are separated from the interstitial fluid by a <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2136\">selectively permeable<\/a> cell membrane that helps regulate the passage of materials between the interstitial fluid and the interior of the cell.<\/p>\n<p style=\"text-align: justify\">The body has other water-based extracellular fluid. These include the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2137\">cerebrospinal fluid<\/a> that bathes the brain and spinal cord, <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2138\">lymph<\/a>, the synovial fluid in joints, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2108\">pleural fluid<\/a> in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2139\">pleural cavities<\/a>, the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2141\">pericardial fluid<\/a> in the <a class=\"glossary-term\" aria-haspopup=\"dialog\" aria-describedby=\"definition\" href=\"#term_1248_2140\">cardiac sac<\/a>, the peritoneal fluid in the peritoneal cavity, and the aqueous humor of the eye. Because these fluids are outside cells, these fluids are also considered components of the extracellular fluid compartment.<\/p>\n<figure id=\"attachment_1749\" aria-describedby=\"caption-attachment-1749\" style=\"width: 723px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-1749 size-large\" src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/2701_Water_Content_in_the_Body-01-fixed-blood-723x1024.png\" alt=\"\" width=\"723\" height=\"1024\" srcset=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/2701_Water_Content_in_the_Body-01-fixed-blood-723x1024.png 723w, https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/2701_Water_Content_in_the_Body-01-fixed-blood-212x300.png 212w, https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/2701_Water_Content_in_the_Body-01-fixed-blood-768x1088.png 768w, https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/2701_Water_Content_in_the_Body-01-fixed-blood-65x92.png 65w, https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/2701_Water_Content_in_the_Body-01-fixed-blood-225x319.png 225w, https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/2701_Water_Content_in_the_Body-01-fixed-blood-350x496.png 350w, https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/2701_Water_Content_in_the_Body-01-fixed-blood.png 1611w\" sizes=\"auto, (max-width: 723px) 100vw, 723px\" \/><figcaption id=\"caption-attachment-1749\" class=\"wp-caption-text\"><strong>Figure 2. Water Content of the Body\u2019s Organs and Tissues.<\/strong> Water content varies in different body organs and tissues, from as little as 8 percent in the teeth to as much as 85 percent in the brain.<\/figcaption><\/figure>\n<figure style=\"width: 668px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image3-2.png\" alt=\"image\" width=\"668\" height=\"449\" \/><figcaption class=\"wp-caption-text\"><strong>Figure 3. Fluid Compartments in the Human Body.<\/strong> The intracellular fluid (ICF) is the fluid within cells. The interstitial fluid (IF) is part of the extracellular fluid (ECF) between the cells. Blood plasma is the second part of the extracellular fluid. Materials travel between cells and the plasma in capillaries through the interstitial fluid.<\/figcaption><\/figure>\n<figure style=\"width: 587px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image4-2.png\" alt=\"image\" width=\"587\" height=\"489\" \/><figcaption class=\"wp-caption-text\"><strong>Figure 4. Proportions of Total Body Fluid in Each of the Body\u2019s Fluid Compartments.<\/strong> Most of the water in the body is intracellular fluid. The second largest volume is the interstitial fluid, which surrounds cells that are not blood cells.<\/figcaption><\/figure>\n<\/div>\n<p><strong style=\"font-size: 1.125em;text-align: justify\">Calculation of the percentage body water<\/strong><\/p>\n<p>Total body water (TBW) is calculated by multiplying 0.6 times your weight in kilograms for males or 0.5 times your weight for females, as follows:<\/p>\n<p>Male: Body weight (kg) x 0.6= TBW (L)<\/p>\n<p>Female: Body weight (kg) x 0.5= TBW (L)<\/p>\n<p>To determine the percentage body water, it is assumed that 1 litre equals 1 kilogram. The average proportions of water present across various compartments of the body are shown in Figure 5.<\/p>\n<figure id=\"attachment_3269\" aria-describedby=\"caption-attachment-3269\" style=\"width: 993px\" class=\"wp-caption alignnone\"><a href=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/Picture1.png\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-3269 size-full\" src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/Picture1.png\" alt=\"Diagram depicts a human silouette indicating that 60% of total body weight is water. Of that portion, 66.6% is intracellular fluid and 33.3% is extracellular fluid, which is 80% interstitial fluid and 20% plasma.\" width=\"993\" height=\"495\" srcset=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/Picture1.png 993w, https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/Picture1-300x150.png 300w, https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/Picture1-768x383.png 768w, https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/Picture1-65x32.png 65w, https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/Picture1-225x112.png 225w, https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/Picture1-350x174.png 350w\" sizes=\"auto, (max-width: 993px) 100vw, 993px\" \/><\/a><figcaption id=\"caption-attachment-3269\" class=\"wp-caption-text\">Figure 5. Average proportions of water present across various compartments of the body. Adapted from https:\/\/nursekey.com\/physiological-changes\/<\/figcaption><\/figure>\n<p>Intracellular fluid volume cannot be measured directly, but it can be calculated from TBW. On average, two thirds (or 66.6%) of the TBW is intracellular, so we calculate two thirds times (or 0.66x) TBW and find a value expressed in litres.<\/p>\n<p>TBW x 2\/3= Intracellular fluid volume (L)<\/p>\n<p>Or<\/p>\n<p>TBW x 0.66= Intracellular fluid (L)<\/p>\n<p>&nbsp;<\/p>\n<p>Extracellular fluid (ECF) can be further broken down into interstitial fluid and blood plasma. Four fifths (or 80%) of the extracellular fluid is composed of interstitial fluid, which is the tissue fluid. The remaining one fifth (or 20%) of the ECF is composed of blood plasma, which is the circulating fluid within blood vessels. The volume of each of these fluid types can be calculated from TBW by first determining the total volume of ECF (one third or 33.3%) and then using that value to determine the volume of interstitial fluid or blood plasma.<\/p>\n<p>TBW (L) x 1\/3= Extracellular fluid volume (L)<\/p>\n<p>Or<\/p>\n<p>TBW (L) \u00a0x 0.33= Extracellular fluid (L)<\/p>\n<p>Let&#8217;s look at two different examples, starting with a female who weighs 50 kilograms. The detailed calculations appear below. As the individual is female, we multiply her body weight by 0.5 to determine TBW, which is 25 litres. Two thirds (66.6%) of the TBW is intracellular. Therefore, we calculate two thirds times (0.66x) 25 litres, which is16.5 litres. One third (33.3%) of TBW is extracellular, so 1\/3 (0.33 x) \u00a025 litres is approximately 8.25 litres. Interstitial fluid accounts for 80% of this extracellular fluid. Thus, four fifths (0.8) times 8.25 litres of interstitial fluid is 6.6 litres, and the remaining 1.65 litres are blood plasma.<\/p>\n<p>50 kg x 0.5= 25 L (TBW)<\/p>\n<p>25 L x 2\/3= 16.5 L (ICF) \u00a0\u00a0or\u00a0 25 x 0.66= 16.5 L (ICF)<\/p>\n<p>25 L x 1\/3=8.25 L (ECF)\u00a0 or\u00a0\u00a0 25 x 0.33= 8.25 L (ECF)<\/p>\n<p>8.25 L x 4\/5= 6.6 L (interstitial fluid)\u00a0 or\u00a0 8.25 x 0.8= 6.6 L (interstitial fluid)<\/p>\n<p>8.25 L x 1\/5= 1.65 L (plasma)\u00a0 or\u00a0 8.25 x 0.2 = 1.65 L (plasma)<\/p>\n<p>Now let us consider a male who weighs 75 kilograms. In this case, we multiply his body weight by 0.6. This gives us a TBW of 45 litres. Two thirds (0.66x) 45 litres gives 29.7 litres of intracellular fluid. One third times (0.33x) 45 litres gives 14.85 litres of extracellular fluid. Of these 14.85 litres, interstitial fluid makes up 11.8 litres and blood plasma makes up 2.97 litres.<\/p>\n<p>75 kg x 0.6= 45 L (TBW)<\/p>\n<p>45 L x 2\/3= 29.7 L (ICF) \u00a0\u00a0\u00a0\u00a0\u00a0or \u00a0\u00a0\u00a0\u00a045 L x 0.66= 29.7 L (ICF)<\/p>\n<p>45 L x 1\/3=14.85 L (ECF)\u00a0\u00a0 \u00a0or \u00a0\u00a0\u00a0\u00a045 L x 0.33= 14.85 L (ECF)<\/p>\n<p>14.85 L x 4\/5= 11.9 L\u00a0\u00a0\u00a0 (interstitial fluid) or 14.85 L x 0.8= 11.9 L (interstitial fluid)<\/p>\n<p>14.85 L x 1\/5= 2.97 L (plasma)\u00a0 \u00a0or \u00a0\u00a014.85L \u00a0x 0.2 = 2.97 L (plasma)<\/p>\n<p><img loading=\"lazy\" decoding=\"async\" style=\"color: #373d3f;font-weight: bold;font-size: 1em\" src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image5-2.png\" alt=\"image\" width=\"146\" height=\"142\" \/><\/p>\n<div class=\"unit-2:-the-chemistry-of-water\">\n<p>Watch <a href=\"https:\/\/youtu.be\/3jwAGWky98c\">this Amoeba Sisters\u2019 video<\/a> to learn more about the properties of water! Direct link:\u00a0<a href=\"https:\/\/youtu.be\/3jwAGWky98c\">https:\/\/youtu.be\/3jwAGWky98c<\/a><\/p>\n<figure style=\"width: 146px\" class=\"wp-caption alignnone\"><img loading=\"lazy\" decoding=\"async\" src=\"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-content\/uploads\/sites\/750\/2019\/07\/image6-2.png\" alt=\"image\" width=\"146\" height=\"146\" \/><figcaption class=\"wp-caption-text\">Watch <a href=\"https:\/\/youtu.be\/HVT3Y3_gHGg\">this CrashCourse video<\/a> to learn more about the importance of water and its chemical properties. Direct link:\u00a0<a href=\"https:\/\/youtu.be\/HVT3Y3_gHGg\">https:\/\/youtu.be\/HVT3Y3_gHGg<\/a><\/figcaption><\/figure>\n<div class=\"textbox textbox--exercises\">\n<header class=\"textbox__header\">\n<p class=\"textbox__title\">Practice Questions<\/p>\n<\/header>\n<div class=\"textbox__content\">\n<p><strong>Part 1.<\/strong> <strong>Biological importance of water<\/strong><\/p>\n<div id=\"h5p-102\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-102\" class=\"h5p-iframe\" data-content-id=\"102\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"2-2\"><\/iframe><\/div>\n<\/div>\n<div id=\"h5p-103\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-103\" class=\"h5p-iframe\" data-content-id=\"103\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"2-3\"><\/iframe><\/div>\n<\/div>\n<p><strong>Part 2.<\/strong> <strong>Fluid compartments in the human body<\/strong><\/p>\n<div id=\"h5p-101\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-101\" class=\"h5p-iframe\" data-content-id=\"101\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"2-1\"><\/iframe><\/div>\n<\/div>\n<\/div>\n<\/div>\n<p>&nbsp;<\/p>\n<\/div>\n<div class=\"glossary\"><span class=\"screen-reader-text\" id=\"definition\">definition<\/span><template id=\"term_1248_2107\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2107\"><div tabindex=\"-1\"><p>Thick, lubricating fluid that fills the interior of a synovial joint.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2108\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2108\"><div tabindex=\"-1\"><p>Substance that acts as a lubricant for the visceral and parietal layers of the pleura during the movement of breathing.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2109\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2109\"><div tabindex=\"-1\"><p>Scatter or break up.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2103\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2103\"><div tabindex=\"-1\"><p>Dipole-dipole bond in which a hydrogen atom covalently bonded to an electronegative atom is weakly attracted to a second electronegative atom.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2063\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2063\"><div tabindex=\"-1\"><p>A substance composed of two or more different elements joined by chemical bonds.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2110\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2110\"><div tabindex=\"-1\"><p>In chemistry, a homogeneous liquid mixture in which a solute is dissolved into molecules within a solvent.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2111\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2111\"><div tabindex=\"-1\"><p>Component of a solution, the substance that dissolves the solute.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2112\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2112\"><div tabindex=\"-1\"><p>Component of a solution, the substance dissolved in a solvent.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2113\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2113\"><div tabindex=\"-1\"><p>Condition in which solute molecules are distributed equally in a solution.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2114\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2114\"><div tabindex=\"-1\"><p>Chemical reaction in which reactants combine to form a new compound, with one reactant gives up an atom of hydrogen and another reactant gives up a hydroxyl group (OH).<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2125\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2125\"><div tabindex=\"-1\"><p>A functional group, OH, present in many organic compounds including alcohols.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2115\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2115\"><div tabindex=\"-1\"><p>Chemical reaction in which a molecule water is split into H and OPH, thereby breaking a bond and severing a compound.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2126\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2126\"><div tabindex=\"-1\"><p>Fluid inside cells.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2127\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2127\"><div tabindex=\"-1\"><p>Fluid outside cells (plasma or interstitial fluid).<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2128\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2128\"><div tabindex=\"-1\"><p>An extracellular fluid, the fluid component of blood.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2129\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2129\"><div tabindex=\"-1\"><p>Extracellular fluid in the small spaces between cells not contained within blood vessels.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2130\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2130\"><div tabindex=\"-1\"><p>Clear, semi-fluid medium of the cytoplasm, made up mostly of water.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2131\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2131\"><div tabindex=\"-1\"><p>Internal material between the cell membrane and nucleus of a cell, mainly consisting of a water-based fluid called cytosol, within which are all the other organelles and cellular solute and suspended materials.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2132\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2132\"><div tabindex=\"-1\"><p>(Also, coagulation factors) group of 12 identified substances active in coagulation.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2133\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2133\"><div tabindex=\"-1\"><p>(Also, immunoglobulin) antigen-specific protein secreted by plasma cells.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2134\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2134\"><div tabindex=\"-1\"><p>A solution containing ions; sometimes referring to ions themselves.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2135\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2135\"><div tabindex=\"-1\"><p>Smallest of the blood vessels where physical exchange occurs between the blood and tissue cells surrounded by interstitial fluid.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2136\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2136\"><div tabindex=\"-1\"><p>Feature of any barrier that allows certain substances to cross but excludes others.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2137\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2137\"><div tabindex=\"-1\"><p>Circulatory medium within the CNS that is produced by ependymal cells in the choroid plexus filtering the blood.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2138\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2138\"><div tabindex=\"-1\"><p>Fluid contained within the lymphatic system, consisting of interstitial fluid, leukocytes (white blood cells), proteins (including antibodies) and fats.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2139\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2139\"><div tabindex=\"-1\"><p>The space between the visceral and parietal pleurae.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2141\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2141\"><div tabindex=\"-1\"><p>Fluid found in the pericardium.<\/p>\n<\/div><button><span aria-hidden=\"true\">&times;<\/span><span class=\"screen-reader-text\">Close definition<\/span><\/button><\/div><\/template><template id=\"term_1248_2140\"><div class=\"glossary__definition\" role=\"dialog\" data-id=\"term_1248_2140\"><div tabindex=\"-1\"><p>Cavity surrounding the heart filled with a lubricating serous fluid that reduces friction as the heart contracts (also, pericardial cavity or cardiac sac).<\/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":10,"menu_order":2,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-1248","chapter","type-chapter","status-publish","hentry"],"part":19,"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/pressbooks\/v2\/chapters\/1248","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/wp\/v2\/users\/10"}],"version-history":[{"count":25,"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/pressbooks\/v2\/chapters\/1248\/revisions"}],"predecessor-version":[{"id":3279,"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/pressbooks\/v2\/chapters\/1248\/revisions\/3279"}],"part":[{"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/pressbooks\/v2\/parts\/19"}],"metadata":[{"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/pressbooks\/v2\/chapters\/1248\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/wp\/v2\/media?parent=1248"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/pressbooks\/v2\/chapter-type?post=1248"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/wp\/v2\/contributor?post=1248"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/dcbiol110311092nded\/wp-json\/wp\/v2\/license?post=1248"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}