Chapter 3 Biological Molecules: The Carbon Compounds of Life PDF

at f., lo 4U m ,. al tr , -1 Su on c 4 s r o.D Bio.2...

at f., lo 4U m ,. al tr , -1 Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M er Te fes r, de 1.0 m of ro rca o 11 Chapter 3 ity t P a o M /2 u1 on.0 ni si ha ti 1 Biological Molecules: The Carbon U s b uc 31 t Su od -2 Compounds of Life r. tr L S D In IO N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  D In IO B he r. tr L A Su od -2 U s b uc 31 ni si ha ti 1 ve st N on.0 rs an S t u1 ity t P a o M /2 of ro rca o 11 Te fes r, de 1.0 xa so Ph rn u1 s r o.D Bio.2 at f., lo 4U D Ins MS gy al tr , -1 la uc M s; ti.S Su on c m ,. m Regulatory Protein and DNA er -2 4 scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Petarg/Shutterstock.com Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be  Why It Matters... at f., lo 4U m ,. al tr , -1 Using energy from sunlight, trees and other plants combine Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M water and carbon dioxide into sugars and other carbon-based er Te fes r, de 1.0 m compounds through the process of photosynthesis of ro rca o 11 ity t P a o M /2 The lives of plants and almost all other organisms depend u1 on.0 directly or indirectly on the products of photosynthesis ni si ha ti 1 U s b uc 31 t Carbon compounds form structures of living organisms, take Su od -2 r. tr L S part in all biological reactions, and serve as energy sources for D In IO N B living organisms and industry (fossil fuels) rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Organic Molecules at f., lo 4U m ,. al tr , -1 Four major classes of organic molecules are found in living Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M organisms: carbohydrates, lipids, proteins, and nucleic acids er Te fes r, de 1.0 m In organic molecules, carbon atoms bond covalently to each of ro rca o 11 ity t P a o M /2 other and to other atoms in molecules that range in size from a u1 on.0 few atoms to thousands or millions of atoms ni si ha ti 1 U s b uc 31 t Molecules consisting of carbon linked only to hydrogen atoms Su od -2 r. tr L S are called hydrocarbons D In IO N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Hydrocarbons (1 of 2) at f., lo 4U m ,. al tr , -1 Carbon has four unpaired outer electrons Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M er The simplest hydrocarbon, CH4 (methane), consists of a single Te fes r, de 1.0 m carbon atom bonded to four hydrogen atoms of ro rca o 11 ity t P a o M /2 u1 More complex hydrocarbons involve two or more carbon atoms on.0 arranged in a linear unbranched chain, a linear branched ni si ha ti 1 U s b uc 31 t chain, or a structure with one or more rings Su od -2 r. tr L S D In IO N Single and double bonds are found in linear and ring B hydrocarbons; triple bonds only in two-carbon hydrocarbons rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he Hydrocarbons (2 of 2) at f., lo 4U m ,. al tr , -1 Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M er Te fes r, de 1.0 m of ro rca o 11 ity t P a o M /2 u1 on.0 ni si ha ti 1 U s b uc 31 t Su od -2 r. tr L S D In IO N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Chemical Evolution at f., lo 4U m ,. al tr , -1 Chemical evolution resulted in the first forms of life on Earth Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M after formation of organic molecules er Te fes r, de 1.0 m Resulted from reactions involving inorganic molecules on primordial of ro rca o 11 ity t P a o M /2 Earth and conditions on the planet at that time u1 on.0 Stanley Miller and Harold Urey performed a classic set of ni si ha ti 1 U s b uc 31 t experiments in 1953 to simulation chemical evolution and Su od -2 r. tr L S formed several complex organic molecules D In IO N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Functional Groups at f., lo 4U m ,. al tr , -1 Functional groups are small, reactive groups of atoms which Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M give larger molecules specific chemical properties er Te fes r, de 1.0 m Functional groups that enter most frequently into biological of ro rca o 11 ity t P a o M /2 reactions are the hydroxyl, carbonyl, carboxyl, amino, u1 on.0 phosphate, and sulfhydryl groups ni si ha ti 1 U s b uc 31 t Functional groups are linked by covalent bonds to other atoms Su od -2 r. tr L S in biological molecules, usually carbon atoms – represented by D In IO N B the collective symbol R rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Hydroxyl and Carbonyl Groups at f., lo 4U m ,. al tr , -1 Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M er Te fes r, de 1.0 m Groups which can of ro rca o 11 donate a “Hydrogen” ion in water, acts as an Acid. ity t P a o M /2 u1 Example: Carboxyl, on.0 phosphate group. ni si ha ti 1 U s b uc 31 t Groups which can accept a “Hydrogen” ion in Su od -2 r. tr L S D In IO water, acts as a Base. N B Example: Amino group. rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he Phosphate, Sulfhydryl, at f., lo 4U m ,. al tr , -1 Su on c and Methyl 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M Groups er Te fes r, de 1.0 m of ro rca o 11 ity t P a o M /2 u1 on.0 ni si ha ti 1 U s b uc 31 t Su od -2 r. tr L S D In IO N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Isomers at f., lo 4U m ,. al tr , -1 Carbons that are linked to four different atoms or functional Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M groups are asymmetric er Te fes r, de 1.0 m Can take either of two fixed positions with respect to other carbons in a of ro rca o 11 ity t P a o M /2 chain u1 on.0 The two forms (isomers) have the same chemical formula, but ni si ha ti 1 U s b uc 31 t have different molecular structures Su od -2 r. tr L S D In IO Example: In glyceraldehyde, the —H and —OH groups can take either N B of two positions, left or right of the carbon chain rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Types of Isomers at f., lo 4U m ,. al tr , -1 Isomers that are mirror images of each other (such as glyceraldehyde) Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 are called stereoisomers xa so Ph rn u1 la uc M er Te fes r, de 1.0 m Typically, only one of the two forms (L-form or D-form) can enter into a reaction of ro rca o 11 ity t P a o M /2 Structural isomers are two molecules with the same chemical formula u1 but atoms are arranged in different ways on.0 ni si ha ti 1 U s b uc 31 Example: glucose, an aldehyde and fructose, a ketone t Su od -2 r. tr L S D In IO N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Stereoisomers (of an amino acid) at f., lo 4U m ,. al tr , -1 Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M er Te fes r, de 1.0 m of ro rca o 11 ity t P a o M /2 Most of the enzymes that Most of the enzymes that u1 catalyze the biochemical catalyze the biochemical on.0 reactions involving amino acids reactions involving sugars ni si ha ti 1 U s b uc 31 recognize the L-stereoisomer. recognize the d stereoisomer t Su od -2 r. tr L S D In IO N B rs an L isomer (L for laevus = left) ve st D isomer (D for dexter = right) A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Structural Isomers at f., lo 4U m ,. al tr , -1 Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M er Te fes r, de 1.0 m of ro rca o 11 (A)In glucose, the aldehyde isomer, the ity t P a o M /2 carbonyl group (shaded region) is located u1 at the end of the carbon chain. on.0 ni si ha ti 1 (B)In fructose, the ketone isomer, the U s b uc 31 t carbonyl group is located inside the Su od -2 carbon chain. For convenience, the r. tr L S D In IO carbons of the sugars are numbered, N B with 1 being the carbon at the end nearest the carbonyl group rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Adding and Removing Water at f., lo 4U m ,. al tr , -1 In many reactions involving Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 functional groups, the xa so Ph rn u1 la uc M er Te fes r, de 1.0 components of a water molecule m of ro rca o 11 (—H and —OH) are removed ity t P a o M /2 from or added to the groups as u1 they interact on.0 ni si ha ti 1 U s b uc 31 t When water components are Su od -2 removed, the reaction is called a r. tr L S D In IO dehydration synthesis reaction or N B condensation reaction rs an When water components are added, ve st the reaction is called hydrolysis A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Macromolecules (1 of 2) at f., lo 4U m ,. al tr , -1 Carbohydrates, lipids, proteins, and nucleic acids are large Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 polymers, assembled from subunit molecules (monomers) into la uc M er Te fes r, de 1.0 m a chain by covalent bonds of ro rca o 11 ity t P a o M /2 Polymers are assembled from monomers (polymerization) by u1 dehydration synthesis reactions on.0 ni si ha ti 1 U s b uc 31 t The breakdown of polymers into monomers occurs by hydrolysis Su od -2 r. tr L S D In IO N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Macromolecules (2 of 2) at f., lo 4U m ,. al tr , -1 Each type of polymeric biological molecule contains one type of monomer Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M er Individual monomers may be identical, or may have chemical variations, depending Te fes r, de 1.0 m on the molecule of ro rca o 11 A single polymer molecule with a mass of 1,000 daltons (Da) or more is ity t P a o M /2 u1 called a macromolecule on.0 ni si ha ti 1 U s b uc 31 Includes many carbohydrates, proteins, and nucleic acids t Su od -2 Lipids are not large enough to be classed as macromolecules r. tr L S D In IO N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  3.2 Carbohydrates at f., lo 4U m ,. al tr , -1 Carbohydrates serve many functions Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M Energy-providing carbohydrates are stored in plant cells as starch, and in animal er Te fes r, de 1.0 cells as glycogen m of ro rca o 11 Structural carbohydrates include cellulose, a primary component of plant cell walls ity t P a o M /2 Carbohydrates contain only carbon, hydrogen, and oxygen atoms in a u1 ratio of about 1C:2H:1O (CH2O) on.0 ni si ha ti 1 U s b uc 31 Monosaccharides contain three to seven carbon atoms t Su od -2 Two monosaccharides polymerize to form a disaccharide r. tr L S D In IO Carbohydrate polymers with more than 10 linked monosaccharide monomers are N B polysaccharides rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Monosaccharides (1 of 2) at f., lo 4U m ,. al tr , -1 Carbohydrates occur either as monosaccharides or as Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M polymers of monosaccharide units er Te fes r, de 1.0 m Monosaccharides (such as glucose, C6H12O6) are soluble in of ro rca o 11 ity t P a o M /2 water and sweet tasting u1 on.0 The most common monosaccharides contain three carbons ni si ha ti 1 U s b uc 31 t (trioses), five carbons (pentoses), or six carbons (hexoses) Su od -2 r. tr L S D In IO N All monosaccharides can occur in linear form B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Monosaccharides (2 of 2) at f., lo 4U m ,. al tr , -1 Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M er Te fes r, de 1.0 m of ro rca o 11 ity t P a o M /2 u1 on.0 ni si ha ti 1 U s b uc 31 t Su od -2 r. tr L S D In IO N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Ring Forms (1 of 2) at f., lo 4U m ,. al tr , -1 Monosaccharides with five or more carbons (such as glucose) Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M can fold back on themselves through a reaction between two er Te fes r, de 1.0 m functional groups to assume a ring form of ro rca o 11 ity t P a o M /2 Glucose exists as two different enantiomers u1 on.0 α-glucose, with an —OH group pointing below the plane of the ring ni si ha ti 1 U s b uc 31 t Su od -2 β-glucose, with an —OH group pointing above the plane r. tr L S D In IO N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Ring Forms (2 of 2) at f., lo 4U m ,. al tr , -1 Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M er Te fes r, de 1.0 m α of ro rca o 11 ity t P a o M /2 u1 on.0 ni si ha ti 1 U s b uc 31 t Su od -2 r. tr L S D In IO N B rs an ve st β A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Disaccharides (1 of 2) at f., lo 4U m ,. al tr , -1 Disaccharides are assembled from two monosaccharides Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M covalently joined by a dehydration synthesis reaction er Te fes r, de 1.0 m Example: Maltose is formed by a glycosidic bond linking two α- of ro rca o 11 ity t P a o M /2 glucose molecules with oxygen as a bridge between the 1 carbon of u1 the first glucose and the 4 carbon of the second glucose unit – an α on.0 ni si ha ti 1 (1→4) linkage U s b uc 31 t Su od -2 Other common disaccharides include sucrose (glucose + fructose) r. tr L S D In IO and lactose (glucose + galactose) N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Disaccharides (2 of 2) at f., lo 4U m ,. al tr , -1 Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M er Te fes r, de 1.0 m of ro rca o 11 ity t P a o M /2 A dehydration synthesis reaction u1 involving two monosaccharides on.0 produces a disaccharide. The ni si ha ti 1 U s b uc 31 components of a water molecule t Su od -2 (in blue) are removed from the r. tr L S monosaccharides as they join. D In IO N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Polysaccharides (1 of 5) at f., lo 4U m ,. al tr , -1 The most common polysaccharides (plant starches, glycogen, Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M and cellulose) are polymers of hundreds or thousands of er Te fes r, de 1.0 m glucose units of ro rca o 11 ity t P a o M /2 Chitin is assembled from glucose units modified by the addition of u1 nitrogen-containing groups on.0 ni si ha ti 1 U s b uc 31 t Polysaccharides may be linear, unbranched molecules, or they Su od -2 r. tr L S may contain one or more branches in which side chains of D In IO N B sugar units are attached to a main chain rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  D In IO B he r. tr L A Su od -2 U s b uc 31 ni si ha ti 1 ve st N on.0 rs an S t u1 ity t P a o M /2 of ro rca o 11 Te fes r, de 1.0 xa so Ph rn u1 s r o.D Bio.2 at f., lo 4U D Ins MS gy al tr , -1 la uc M s; ti.S Su on c Polysaccharides (2 of 5) m ,. m er -2 4 scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be Ed Reschke/Photolibrary/Getty Images  D In IO B he r. tr L A Su od -2 U s b uc 31 ni si ha ti 1 ve st N on.0 rs an S t u1 ity t P a o M /2 of ro rca o 11 Te fes r, de 1.0 xa so Ph rn u1 s r o.D Bio.2 at f., lo 4U D Ins MS gy al tr , -1 la uc M s; ti.S Su on c Polysaccharides (3 of 5) m ,. m er -2 4 scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Mike Rosecope/Shutterstock.com Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be  D In IO B he r. tr L A Su od -2 U s b uc 31 ni si ha ti 1 ve st N on.0 rs an S t u1 ity t P a o M /2 of ro rca o 11 Te fes r, de 1.0 xa so Ph rn u1 s r o.D Bio.2 at f., lo 4U D Ins MS gy al tr , -1 la uc M s; ti.S Su on c Polysaccharides (4 of 5) m ,. m er -2 4 scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be Biophoto Associates/Science Source  D In IO B he r. tr L A Su od -2 U s b uc 31 ni si ha ti 1 ve st N on.0 rs an S t u1 ity t P a o M /2 of ro rca o 11 Te fes r, de 1.0 xa so Ph rn u1 s r o.D Bio.2 at f., lo 4U D Ins MS gy al tr , -1 la uc M s; ti.S Su on c Polysaccharides (5 of 5) m ,. m er -2 4 scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. Carolina K. Smith MD/Shutterstock.com Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be  3.3 Lipids at f., lo 4U m ,. al tr , -1 Lipids are water-insoluble, primarily nonpolar biological Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M molecules composed mostly of hydrocarbons er Te fes r, de 1.0 m Three common types of lipid molecules: of ro rca o 11 ity t P a o M /2 u1 Neutral lipids are stored and used as an energy source on.0 ni si ha ti 1 Phospholipids form cell membranes U s b uc 31 t Su od -2 Steroids serve as hormones that regulate cellular activities r. tr L S D In IO N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Neutral Lipids at f., lo 4U m ,. al tr , -1 Neutral lipids, found in cells as energy-storage molecules, Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M have no charged groups (nonpolar) er Te fes r, de 1.0 m There are two types of neutral lipids: of ro rca o 11 ity t P a o M /2 u1 Oils are liquid at biological temperatures on.0 ni si ha ti 1 Fats are semisolid U s b uc 31 t Su od -2 A fatty acid contains a single hydrocarbon chain with a r. tr L S D In IO N carboxyl group (—COOH) at one end B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Glycerol and Triglyceride Formation at f., lo 4U m ,. al tr , -1 Triglycerides form by dehydration synthesis between three- Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M carbon glycerol (an alcohol) and three fatty acid side chains er Te fes r, de 1.0 m A covalent bond (ester linkage) forms between the -COOH group of of ro rca o 11 ity t P a o M /2 the fatty acid and the -OH group of the glycerol u1 on.0 The polar groups of glycerol are eliminated, forming a nonpolar ni si ha ti 1 U s b uc 31 triglyceride t Su od -2 r. tr L S D In IO N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Triglycerides at f., lo 4U m ,. al tr , -1 Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 (A) Formation of a xa so Ph rn u1 la uc M er triglyceride by dehydration Te fes r, de 1.0 m synthesis of glycerol with of ro rca o 11 three fatty acids. The fatty ity t P a o M /2 acid shown is palmitic acid, u1 and the triglyceride product on.0 is glyceryl palmitate. The ni si ha ti 1 U s b uc 31 components of a water t molecule (in blue) are Su od -2 r. tr L S removed from the glycerol D In IO N and fatty acids in each of B the three bonds formed. rs an (B) Spacefilling model of ve st the triglyceride, glyceryl palmitate. A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Saturated and Unsaturated Fatty Acids (1 of 2) at f., lo 4U m ,. al tr , -1 Su on c 4 s r o.D Bio.2 The most common fatty acids have chains of 14 to 22 carbons s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M er Te fes r, de 1.0 As chain length increases, fatty acids become less water-soluble and m of ro rca o 11 more oily ity t P a o M /2 u1 A saturated fatty acid binds the maximum number of hydrogen on.0 ni si ha ti 1 atoms U s b uc 31 t Su od -2 Only single bonds exist between carbon atoms r. tr L S D In IO N B Fatty acids with one double bond are monounsaturated; rs an those with more than on double bond are polyunsaturated ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Saturated and Unsaturated Fatty Acids (2 of 2) at f., lo 4U m ,. al tr , -1 Unsaturated fatty acids (such as vegetable oils) bend at a Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M double bond (called “kink”) and are more fluid at biological er Te fes r, de 1.0 m temperatures of ro rca o 11 ity t P a o M /2 Saturated fatty acids are found in solid animal fats such as u1 on.0 butter ni si ha ti 1 U s b uc 31 t Unsaturated fats are considered healthier than saturated fats in Su od -2 r. tr L S the human diet D In IO N B Plant oils are converted commercially to saturated fats by rs an ve st hydrogenation A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Fatty Acids at f., lo 4U m ,. al tr , -1 Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M er Te fes r, de 1.0 m of ro rca o 11 ity t P a o M /2 u1 on.0 ni si ha ti 1 (A) Stearic acid, a saturated fatty acid. U s b uc 31 t kink Su od -2 (B) Oleic acid, an unsaturated fatty r. tr L S D In IO acid. An arrow marks the “kink” N B introduced by the double bond. rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Functions of Triglycerides at f., lo 4U m ,. al tr , -1 Triglycerides serve as energy reserves in animals Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M er Store more than twice the calories per gram as carbohydrates Te fes r, de 1.0 m of ro rca o 11 ity t P a o M /2 u1 A layer of fatty tissue just under the skin acts as insulation in on.0 ni si ha ti 1 mammals and birds (e.g., penguins) U s b uc 31 t Su od -2 Triglycerides also help make bird feathers waterproof r. tr L S D In IO N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Focus on Research (1 of 2) at f., lo 4U m ,. al tr , -1 Atherosclerosis Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M occurs from the er Te fes r, de 1.0 m build up of of ro rca o 11 plaques in the ity t P a o M /2 u1 coronary arteries on.0 ni si ha ti 1 U s b uc 31 t Plaques form from the buildup Su od -2 r. tr L S Micrograph Louis L. Lainey D In IO N of excess B cholesterol rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Waxes at f., lo 4U m ,. al tr , -1 Fatty acids combine with long-chain alcohols or hydrocarbon Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 structures to form waxes, which are harder and less greasy la uc M er Te fes r, de 1.0 m than fats of ro rca o 11 ity t P a o M /2 u1 on.0 Waxy coatings help animals keep skin, hair, or feathers protected, ni si ha ti 1 U s b uc 31 t lubricated, and pliable Su od -2 r. tr L S D In IO N B Plants secrete waxes that form a protective exterior layer, which rs an ve st reduces water loss and resists infective agents A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Phospholipids at f., lo 4U m ,. al tr , -1 Phosphate-containing phospholipids are the primary lipids of Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M cell membranes er Te fes r, de 1.0 m The most common phospholipid has a glycerol backbone of ro rca o 11 ity t P a o M /2 linked to two fatty acid chains and a polar phosphate group, u1 on.0 which is linked to another polar group ni si ha ti 1 U s b uc 31 t The end of the molecule containing the fatty acids is nonpolar and Su od -2 r. tr L S hydrophobic, and the end with the phosphate group is polar and D In IO N B hydrophilic rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Phospholipid Bilayer at f., lo 4U m ,. al tr , -1 In watery environments, only the polar ends of phospholipid Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M molecules are exposed to water; their nonpolar ends collect er Te fes r, de 1.0 m together in a region that excludes water of ro rca o 11 ity t P a o M /2 u1 on.0 The phospholipid bilayer – a film of phospholipids two ni si ha ti 1 U s b uc 31 t molecules thick – is the structural basis of membranes Su od -2 r. tr L S D In IO N In a bilayer, the polar groups face the surrounding water molecules at B the surfaces of the bilayer – the hydrocarbon chains form a nonpolar, rs an hydrophobic region in the interior ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Phospholipid Structure at f., lo 4U m ,. al tr , -1 (A) The arrangement of Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy components in phospholipids. -2 xa so Ph rn u1 la uc M er (B) Phosphatidyl ethanolamine, a Te fes r, de 1.0 m common membrane of ro rca o 11 phospholipid. (C) Space-filling ity t P a o M /2 model of phosphatidyl u1 ethanolamine. The kink in the on.0 fatty acid chain on the right ni si ha ti 1 reflects a double bond at this U s b uc 31 t position. (D) Diagram widely used Su od -2 to depict a phospholipid molecule r. tr L S D In IO in cell membrane diagrams. The N B sphere represents the polar end of the molecule, and the zigzag rs an lines represent the nonpolar fatty ve st acid chains. (The kink in the fatty acid chain is not shown.) A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Steroids (1 of 2) at f., lo 4U m ,. al tr , -1 Steroids are lipids with structures based on a framework of Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M four carbon rings er Te fes r, de 1.0 m Sterols, the most common steroids, have a single polar OH of ro rca o 11 ity t P a o M /2 group linked to one end of the ring framework and a complex, u1 on.0 nonpolar hydrocarbon chain at the other end ni si ha ti 1 U s b uc 31 t Cholesterol is an important component of animal cell membranes Su od -2 r. tr L S D In IO Similar sterols (phytosterols) occur in plant cell membranes N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Steroids (2 of 2) at f., lo 4U m ,. al tr , -1 Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M er Te fes r, de 1.0 m of ro rca o 11 (A) Typical arrangement of four carbon rings in ity t P a o M /2 u1 a steroid molecule. on.0 ni si ha ti 1 (B) A sterol, cholesterol. Sterols have a U s b uc 31 t hydrocarbon side chain linked to the ring Su od -2 structure at one end and a single -OH group r. tr L S D In IO at the other end (boxed in red). The -OH N B group makes its end of a sterol slightly polar. The rest of the molecule is nonpolar. rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Steroid Hormones at f., lo 4U m ,. al tr , -1 Steroid hormones control development, behavior, and many Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M internal biochemical processes er Te fes r, de 1.0 m Examples: The sex hormones that control differentiation of the sexes of ro rca o 11 ity t P a o M /2 and sexual behavior u1 on.0 Estradiol (female sex hormone) has an —OH in the position where testosterone ni si ha ti 1 U s b uc 31 (male sex hormone) has an =O, and testosterone has a methyl group (—CH3) that t Su od -2 is absent from estradiol r. tr L S D In IO N B rs an Difference between Estradiol and Testosterone ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Steroid Sex Hormones at f., lo 4U m ,. al tr , -1 Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M er Te fes r, de 1.0 m The female sex hormone, of ro rca o 11 estradiol (A), and the ity t P a o M /2 male sex hormone, u1 testosterone (B), differ on.0 only in substitution of an - ni si ha ti 1 U s b uc 31 t OH group for an oxygen Su od -2 r. tr L and the absence of one S methyl group (-CH3) in the D In IO N estrogen. Although small, B these differences greatly rs an alter sexual structures and ve st behavior in animals, such as humans. A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Other Lipids at f., lo 4U m ,. al tr , -1 Several other lipid types have structures unrelated to Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M triglycerides, phospholipids, or steroids er Te fes r, de 1.0 m Chlorophylls and carotenoids are pigments that absorb light and help of ro rca o 11 ity t P a o M /2 convert it to chemical energy in plants u1 on.0 Lipid groups combine with carbohydrates to form glycolipids, and with ni si ha ti 1 U s b uc 31 proteins to form lipoproteins, which have important structural and t Su od -2 functional roles in cell membranes r. tr L S D In IO N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  3.4 Proteins at f., lo 4U m ,. al tr , -1 Proteins perform many vital functions in living organisms Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M er Structural support; enzymes; movement; transport; recognition and Te fes r, de 1.0 m receptor molecules; regulation of proteins and DNA; hormones; of ro rca o 11 antibodies; toxins and venoms ity t P a o M /2 u1 on.0 Proteins are macromolecules ni si ha ti 1 U s b uc 31 t Polymers of amino acid monomers, which contain both an amino and a Su od -2 r. tr L S carboxyl group D In IO N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he Major Protein Functions (1 of 2) at f., lo 4U m ,. al tr , -1 Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M er Te fes r, de 1.0 m of ro rca o 11 ity t P a o M /2 u1 on.0 ni si ha ti 1 U s b uc 31 t Su od -2 r. tr L S D In IO N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he Major Protein Functions (2 of 2) at f., lo 4U m ,. al tr , -1 Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M er Te fes r, de 1.0 m of ro rca o 11 ity t P a o M /2 u1 on.0 ni si ha ti 1 U s b uc 31 t Su od -2 r. tr L S D In IO N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a publicly accessible website, in whole or in part. he  Amino Acids (1 of 4) at f., lo 4U m ,. al tr , -1 All organisms use 20 different amino acids to build proteins Su on c 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M er Most have the same structural plan: a central carbon atom is Te fes r, de 1.0 m attached to an amino group, a carboxyl group, a hydrogen of ro rca o 11 ity t P a o M /2 atom, and a variable R group u1 on.0 ni si ha ti 1 U s b uc 31 t Su od -2 r. tr L S D In IO N B rs an ve st A Russell, Biology: The Dynamic Science, 5th edition. © 2021 Cengage. All Rights Reserved. May not be scanned, copied or duplicated, or posted to a pub