Chapter 3 The Chemical Building Blocks of Life PDF

Because learning changes everything.® Chapter 3 The Chemical Building Blocks of Life Understanding Biology Fourth Edition Kenneth A. Mason, Tod Duncan Jonathan B. Losos © McGraw Hill LLC. All rights...

Because learning changes everything.® Chapter 3 The Chemical Building Blocks of Life Understanding Biology Fourth Edition Kenneth A. Mason, Tod Duncan Jonathan B. Losos © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.  The Chemical Building Blocks of Life Deco/Alamy Stock Photo © McGraw Hill, LLC 2  Carbon Framework of biological molecules consists primarily of carbon bonded to: Carbon O, N, S, P or H Organic molecules. Can form up to 4 covalent bonds Hydrocarbons – molecule consisting only of carbon and hydrogen Nonpolar Functional groups add chemical properties © McGraw Hill, LLC 3  Figure 3.1 Access the text alternative for these images © McGraw Hill, LLC 4  Isomers Molecules with the same molecular or empirical formula but a different arrangement of atoms. Structural isomers - differ in the actual carbon structure Stereoisomers – differ in the spatial arrangement of attached groups. Enantiomers mirror image molecules chiral D-sugars and L-amino acids © McGraw Hill, LLC 5  Isomers © McGraw Hill, LLC 6  Figure 3.2 Access the text alternative for these images © McGraw Hill, LLC 7  Macromolecules 1 Four general classes Carbohydrates Proteins Nucleic acids Lipids (not polymers) Polymer – built by linking monomers Monomer – small, similar chemical subunits © McGraw Hill, LLC 8  Macromolecules 2 TABLE 3.1 Macromolecules Macromolecule Subunit Function Example CARBOHYDRATES Blank Blank Blank Starch, glycogen Glucose Energy storage Potatoes Cellulose Glucose Structural support in plant cell walls Paper; strings of celery Chitin Modified glucose Structural support Crab shells PROTEINS Blank Blank Blank Functional Amino acids Catalysis; transport Hemoglobin Structural Amino acids Support Hair; silk NUCLEIC ACIDS Blank Blank Blank DNA Nucleotides Encodes genes Chromosomes RNA Nucleotides Needed for gene expression Messenger RNA LIPIDS Blank Blank Blank Fats Glycerol and three fatty acids Energy storage Butter; corn oil; soap Phospholipids Glycerol, two fatty acids, Cell membranes Phosphatidylcholine phosphate, and polar R groups Prostaglandins Five-carbon rings with two Chemical messengers Prostaglandin E (PGE) nonpolar tails Steroids Four fused carbon rings Membranes; hormones Cholesterol; estrogen Terpenes Long carbon chains Pigments; structural support Carotene; rubber © McGraw Hill, LLC 9  Figure 3.3 Dehydration synthesis Formation of large molecules by the removal of water Monomers are joined to form polymers Hydrolysis Breakdown of large molecules by the addition of water Polymers are broken down to monomers Access the text alternative for these images © McGraw Hill, LLC 10  Carbohydrates Molecules with a 1 : 2 : 1 ratio of carbon, hydrogen, oxygen Empirical formula C—H covalent bonds hold much energy Carbohydrates are good energy storage molecules Examples: sugars, starch, glucose © McGraw Hill, LLC 11  Monosaccharides Simplest carbohydrate 6 carbon sugars play important roles Glucose Fructose is a structural isomer of glucose Galactose is a stereoisomer of glucose Enzymes that act on different sugars can distinguish structural and stereoisomers of this basic six-carbon skeleton © McGraw Hill, LLC 12  Figure 3.4 Access the text alternative for these images © McGraw Hill, LLC 13  Figure 3.5 Structure of the glucose molecule Access the text alternative for these images © McGraw Hill, LLC 14  Figure 3.6 Structural isomers and stereoisomers Access the text alternative for these images © McGraw Hill, LLC 15  Disaccharides Two monosaccharides linked together by dehydration synthesis Used for sugar transport or energy storage Examples: sucrose, lactose, maltose Access the text alternative for these images © McGraw Hill, LLC 16  Polysaccharides Long chains of monosaccharides Linked through dehydration synthesis Energy storage Plants use starch (alpha 1→4 linkage) Animals use glycogen Structural support Plants use cellulose (beta 1→4 linkage) Arthropods and fungi use chitin © McGraw Hill, LLC 17  Figure 3.8 (b): Asa Thoresen/Science Source; (c): J.L. Carson/CMSP Biology/Newscom Access the text alternative for these images © McGraw Hill, LLC 18  Figure 3.9 (b): Jim Zuckerman/age fotostock Access the text alternative for these images © McGraw Hill, LLC 19  Which of the following is a dehydration reaction? A. A + B → C + H2O A. A + H2O → B + C A. A → B + C + H2O A. A + B + H2O → C © McGraw Hill, LLC 20  Which of the following is a dehydration reaction? A. A + B → C + H2O A. A + H2O → B + C A. A → B + C + H2O A. A + B + H2O → C © McGraw Hill, LLC 21  Proteins Protein functions include: Enzyme catalysis Defense Transport Support Motion Regulation Storage © McGraw Hill, LLC 22  Amino acids Proteins are polymers Composed of 1 or more long, unbranched chains Each chain is a polypeptide Amino acids are monomers Amino acid structure Central carbon atom Amino group (NH2) Carboxyl group (acidic) Single hydrogen Variable R group © McGraw Hill, LLC 23  R Groups R groups determine the chemistry of the amino acid: Nonpolar – leucine Polar uncharged – threonine Charged – glutamic acid Aromatic – phenylalanine Unique – proline and cysteine © McGraw Hill, LLC 24  Figure 3.12 Great resources online for learning these including quizzlets, quiz apps, youtube songs! Access the text alternative for these images © McGraw Hill, LLC 25  Figure 3.11 Amino acids joined by dehydration synthesis Peptide bond Access the text alternative for these images © McGraw Hill, LLC 26  Protein structure (primary and secondary) The shape of a protein determines its function Primary structure – sequence of amino acids Secondary structure – interaction of groups in the peptide backbone α helix - coiled into a spiral structure β sheet - peptides aligned together to form a planar structure. © McGraw Hill, LLC 27  Protein structure (tertiary and quaternary) Tertiary structure – final folded shape of a globular protein Stabilized by a number of forces Final level of structure for proteins consisting of only a single polypeptide chain Quaternary structure – arrangement of individual chains (subunits) in a protein with two or more polypeptide chains © McGraw Hill, LLC 28  Figure 3.13 Access the text alternative for these images © McGraw Hill, LLC 29  Additional structural characteristics Motifs Common elements of secondary structure seen in many polypeptides Useful in determining the function of unknown proteins Domains Functional units within a larger structure Most proteins made of multiple domains that perform different parts of the protein’s function © McGraw Hill, LLC 30  Figure 3.16 Access the text alternative for these images © McGraw Hill, LLC 31  Chaperones Once thought newly made proteins folded spontaneously Chaperone proteins help protein fold correctly Studies show that defective chaperone proteins can result in other proteins failing to fold properly © McGraw Hill, LLC 32  Figure 3.17 Access the text alternative for these images © McGraw Hill, LLC 33  Denaturation Protein loses structure and function Due to environmental conditions pH Temperature Ionic concentration of solution © McGraw Hill, LLC 34  Luke sprained his ankle, tearing some of the collagen protein that forms his ligaments. Some types of collagen consist of three polypeptide chains twisted together to form a rope-like strand. What level of protein structure does this rope-like strand represent? A. Primary A. Secondary A. Quaternary A. Tertiary © McGraw Hill, LLC 35  Luke sprained his ankle, tearing some of the collagen protein that forms his ligaments. Some types of collagen consist of three polypeptide chains twisted together to form a rope-like strand. What level of protein structure does this rope-like strand represent? A. Primary A. Secondary A. Quaternary A. Tertiary © McGraw Hill, LLC 36  Nucleic acids Polymer – nucleic acids Monomers – nucleotides sugar + phosphate + nitrogenous base sugar is deoxyribose in DNA or ribose in RNA Nitrogenous bases include Purines: adenine and guanine Pyrimidines: thymine, cytosine, uracil Nucleotides connected by phosphodiester bonds © McGraw Hill, LLC 37  Figure 3.21 Access the text alternative for these images © McGraw Hill, LLC 38  Figure 3.22 Access the text alternative for these images © McGraw Hill, LLC 39  Figures 3.23 Moves 5’ → 3’ Access the text alternative for these images © McGraw Hill, LLC 40  Figure 3.20 DNA versus RNA DNA forms a double helix, uses deoxyribose, and uses thymine among its nitrogenous bases RNA is usually single- stranded, uses ribose, and uses uracil in place of thymine Access the text alternative for these images © McGraw Hill, LLC 41  Deoxyribonucleic acid (DNA) Encodes information for amino acid sequence of proteins Sequence of bases Double helix – 2 polynucleotide strands connected by hydrogen bonds Base-pairing rules A with T (or U in RNA) C with G Purine → Pyrimidine © McGraw Hill, LLC 42  Figure 3.24 Access the text alternative for these images © McGraw Hill, LLC 43  Ribonucleic acid (RNA) RNA similar to DNA except Contains ribose instead of deoxyribose Contains uracil instead of thymine Usually a single polynucleotide strand RNA uses information in DNA to specify sequence of amino acids in proteins mRNA, rRNA, tRNA Other RNA varieties as well © McGraw Hill, LLC 44  Other nucleotides ATP – adenosine triphosphate Primary energy currency of the cell Electron carriers for many cellular reactions Access the text alternative for these images © McGraw Hill, LLC 45  The nitrogenous base that is only found in RNA and not DNA is __________blank. A. Uracil A. Cytosine A. Thymine A. Guanine A. None. They have identical bases. © McGraw Hill, LLC 46  The nitrogenous base that is only found in RNA and not DNA is __________blank. A. Uracil A. Cytosine A. Thymine A. Guanine A. None. They have identical bases. © McGraw Hill, LLC 47  Lipids Hydrophobic lipids form fats and membranes Loosely defined group of molecules with one main chemical characteristic They are insoluble in water High proportion of nonpolar C—H bonds causes the molecule to be hydrophobic Fats, oils, waxes, some vitamins, etc. © McGraw Hill, LLC 48  Fats Triglycerides Composed of 1 glycerol and 3 fatty acids Fatty acids Need not be identical!!! Chain length varies Saturated – no double bonds between carbon atoms Unsaturated – 1 or more double bonds Trans fats produced industrially - double bonds on the opposite side. © McGraw Hill, LLC 49  Figure 3.26 Access the text alternative for these images © McGraw Hill, LLC 50  Phospholipids Composed of Glycerol - 3 carbon alcohol. 2 fatty acids – nonpolar “tails” A phosphate group – polar “head” Form all biological membranes © McGraw Hill, LLC 51  Figure 3.28 Access the text alternative for these images © McGraw Hill, LLC 52  Figure 3.29a Micelles – lipid molecules orient with polar (hydrophilic) head toward water and nonpolar (hydrophobic) tails away from water Access the text alternative for these images © McGraw Hill, LLC 53  Figure 3.29b Phospholipid bilayer – more complicated structure where 2 layers form Hydrophilic heads point outward Hydrophobic tails point inward toward each other Access the text alternative for these images © McGraw Hill, LLC 54  Figure 3.27 Other kinds of lipids a. Terpenes are found in biological pigments, such as chlorophyll and retinal b. Steroids play important roles in membranes and as hormones involved in chemical signaling Access the text alternative for these images © McGraw Hill, LLC 55  The biological macromolecule that is least soluble in water is a/an __________blank. A. Enzyme A. Protein A. Carbohydrate A. Nucleic Acid A. Lipid © McGraw Hill, LLC 56  The biological macromolecule that is least soluble in water is a/an __________blank. A. Enzyme A. Protein A. Carbohydrate A. Nucleic Acid A. Lipid © McGraw Hill, LLC 57 Because learning changes everything. ® www.mheducation.com © McGraw Hill LLC. All rights reserved. No reproduction or distribution without the prior written consent of McGraw Hill LLC.