Chapter 3 Biological Processes PDF

Why It Matters... at f., lo 4U m ,. al tr , -1 Su on c Using energy from sunlig...

Why It Matters... at f., lo 4U m ,. al tr , -1 Su on c Using energy from sunlight, trees and other plants combine 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 D In IO part in all biological reactions, and serve as energy sources for 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 Su on c Four major classes of organic molecules are found in living 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 of ro rca o 11 In organic molecules, carbon atoms bond covalently to each 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 D In IO are called hydrocarbons 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 Su on c Carbon has four unpaired outer electrons 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 of ro rca o 11 carbon atom bonded to four hydrogen atoms ity t P a o M /2 u1 More complex hydrocarbons involve two or more carbon atoms on.0 ni si ha ti 1 arranged in a linear unbranched chain, a linear branched 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 rs an hydrocarbons; triple bonds only in two-carbon hydrocarbons 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 Su on c Chemical evolution resulted in the first forms of life on Earth 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 of ro rca o 11 Resulted from reactions involving inorganic molecules on primordial 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 Su on c Functional groups are small, reactive groups of atoms which 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 of ro rca o 11 Functional groups that enter most frequently into biological 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 D In IO in biological molecules, usually carbon atoms – represented by 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 ity t P a o M /2 in water, acts as an Acid. 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 er Groups 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 Su on c Carbons that are linked to four different atoms or functional 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 of ro rca o 11 Can take either of two fixed positions with respect to other carbons in a 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 Su on c Isomers that are mirror images of each other (such as glyceraldehyde) 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 are called stereoisomers 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 t Example: glucose, an aldehyde and fructose, a ketone 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 t recognize the L-stereoisomer. recognize the d stereoisomer 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 rs an ve st nearest the carbonyl group 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 xa so Ph rn u1 functional groups, the 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 Su on c Carbohydrates, lipids, proteins, and nucleic acids are large 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M polymers, assembled from subunit molecules (monomers) into 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 Su on c Each type of polymeric biological molecule contains one type of monomer 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 ity t P a o M /2 A single polymer molecule with a mass of 1,000 daltons (Da) or more is 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 Su on c Carbohydrates serve many functions 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 m cells as glycogen 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 on.0 ratio of about 1C:2H:1O (CH2O) 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 Su on c Carbohydrates occur either as monosaccharides or as 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 of ro rca o 11 Monosaccharides (such as glucose, C6H12O6) are soluble in ity t P a o M /2 water and sweet tasting u1 on.0 ni si ha ti 1 The most common monosaccharides contain three carbons 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 Su on c Monosaccharides with five or more carbons (such as glucose) 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 ni si ha ti 1 α-glucose, with an —OH group pointing below the plane of the ring 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 Su on c Disaccharides are assembled from two monosaccharides 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 of ro rca o 11 Example: Maltose is formed by a glycosidic bond linking two α- 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 t components of a water molecule 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 Su on c The most common polysaccharides (plant starches, glycogen, 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 Su on c Lipids are water-insoluble, primarily nonpolar biological 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 of ro rca o 11 Three common types of lipid molecules: 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 Su on c Neutral lipids, found in cells as energy-storage molecules, 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 of ro rca o 11 There are two types of neutral lipids: 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 Su on c Triglycerides form by dehydration synthesis between three- 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 of ro rca o 11 A covalent bond (ester linkage) forms between the -COOH group of 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 t triglyceride 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 Su od -2 r. tr L molecule (in blue) are 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 s; ti.S The most common fatty acids have chains of 14 to 22 carbons D Ins MS gy -2 xa so Ph rn u1 la uc M er Te fes r, de 1.0 m As chain length increases, fatty acids become less water-soluble and 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 Su on c Unsaturated fatty acids (such as vegetable oils) bend at a 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 D In IO the human diet N B rs an Plant oils are converted commercially to saturated fats by 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 Su on c Triglycerides serve as energy reserves in animals 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 Su on c Atherosclerosis 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 Su od -2 r. tr L from the buildup 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 Su on c Fatty acids combine with long-chain alcohols or hydrocarbon 4 s r o.D Bio.2 s; ti.S D Ins MS gy -2 xa so Ph rn u1 la uc M structures to form waxes, which are harder and less greasy 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 ni si ha ti 1 Waxy coatings help animals keep skin, hair, or feathers protected, U s b uc 31 t lubricated, and pliable Su od -2 r. tr L S D In IO N B rs an Plants secrete waxes that form a protective exterior layer, which 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 Su on c Phosphate-containing phospholipids are the primary lipids of 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 of ro rca o 11 The most common phospholipid has a glycerol backbone 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 Su on c In watery environments, only the polar ends of phospholipid 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 ni si ha ti 1 The phospholipid bilayer – a film of phospholipids two 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 ve st hydrophobic region in the interior 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 -2 components in phospholipids. 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 rs an ve st of the molecule, and the zigzag lines represent the nonpolar fatty acid chains. (The kink in the fatty A acid chain is not shown.) 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 Su on c Steroids are lipids with structures based on a framework of 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 of ro rca o 11 Sterols, the most common steroids, have a single polar OH 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 N Similar sterols (phytosterols) occur in plant cell membranes 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 ity t P a o M /2 (A) Typical arrangement of four carbon rings in 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 rs an ve st polar. The rest of the molecule is nonpolar. 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 Su on c Steroid hormones control development, behavior, and many 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 of ro rca o 11 Examples: The sex hormones that control differentiation of the sexes 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 Su on c Several other lipid types have structures unrelated to 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 of ro rca o 11 Chlorophylls and carotenoids are pigments that absorb light and help 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 t proteins to form lipoproteins, which have important structural and 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 Su on c Proteins perform many vital functions in living organisms 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 ity t P a o M /2 antibodies; toxins and venoms 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