Presentation is loading. Please wait.

Presentation is loading. Please wait.

Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. CHAPTER 3 LECTURE SLIDES To run the animations you must be.

Similar presentations

Presentation on theme: "Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. CHAPTER 3 LECTURE SLIDES To run the animations you must be."— Presentation transcript:

1 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. CHAPTER 3 LECTURE SLIDES To run the animations you must be in Slideshow View. Use the buttons on the animation to play, pause, and turn audio/text on or off. Please note: once you have used any of the animation functions (such as Play or Pause), you must first click in the white background before you advance the next slide.

2 The Chemical Building Blocks of Life Chapter 3

3 3 Carbon Framework of biological molecules consists primarily of carbon bonded to –Carbon –O, N, S, P or H Can form up to 4 covalent bonds Hydrocarbons – molecule consisting only of carbon and hydrogen –Nonpolar –Functional groups add chemical properties

4 4

5 5 Isomers Molecules with the same molecular or empirical formula –Structural isomers –Stereoisomers – differ in how groups attached Enantiomers –mirror image molecules –chiral –D-sugars and L-amino acids

6 6

7 7 Macromolecules Polymer – built by linking monomers Monomer – small, similar chemical subunits

8 8 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

9 9 Carbohydrates Molecules with a 1:2:1 ratio of carbon, hydrogen, oxygen Empirical formula (CH 2 O) n CH covalent bonds hold much energy –Carbohydrates are good energy storage molecules –Examples: sugars, starch, glucose

10 10 Monosaccharides Simplest carbohydrate 6 carbon sugars play important roles Glucose C 6 H 12 O 6 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

11 11

12 12

13 13 Disaccharides 2 monosaccharides linked together by dehydration synthesis Used for sugar transport or energy storage Examples: sucrose, lactose, maltose

14 14 Polysaccharides Long chains of monosaccharides –Linked through dehydration synthesis Energy storage –Plants use starch –Animals use glycogen Structural support –Plants use cellulose –Arthropods and fungi use chitin

15 15

16 16

17 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 17

18 18

19 19

20 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 20

21 21

22 22 Ribonucleic acid (RNA) RNA similar to DNA except –Contains ribose instead of deoxyribose –Contains uracil instead of thymine Single polynucleotide strand RNA uses information in DNA to specify sequence of amino acids in proteins

23 23

24 24 Other nucleotides ATP adenosine triphosphate –Primary energy currency of the cell NAD + and FAD + –Electron carriers for many cellular reactions

25 25 Proteins Protein functions include: 1. Enzyme catalysis 2. Defense 3. Transport 4. Support 5. Motion 6. Regulation 7. Storage

26 26 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 –Carboxyl group –Single hydrogen –Variable R group

27 27

28 28 Amino acids joined by dehydration synthesis –Peptide bond

29 29 4 Levels of structure The shape of a protein determines its function 1.Primary structure – sequence of amino acids 2.Secondary structure – interaction of groups in the peptide backbone – helix – sheet

30 4 Levels of structure 3.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 4.Quaternary structure – arrangement of individual chains (subunits) in a protein with 2 or more polypeptide chains 30

31 31

32 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 proteins function 32

33 33

34 34 Once thought newly made proteins folded spontaneously Chaperone proteins help protein fold correctly Deficiencies in chaperone proteins implicated in certain diseases –Cystic fibrosis is a hereditary disorder In some individuals, protein appears to have correct amino acid sequence but fails to fold Chaperones

35 35

36 Denaturation Protein loses structure and function Due to environmental conditions –pH –Temperature –Ionic concentration of solution 36

37 37 Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the Normal or Slide Sorter views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at

38 38 Lipids Loosely defined group of molecules with one main chemical characteristic –They are insoluble in water High proportion of nonpolar CH bonds causes the molecule to be hydrophobic Fats, oils, waxes, and even some vitamins

39 39 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 Higher melting point, animal origin –Unsaturated – 1 or more double bonds Low melting point, plant origin –Trans fats produced industrially

40 40

41 41 Phospholipids Composed of –Glycerol –2 fatty acids – nonpolar tails –A phosphate group – polar head Form all biological membranes

42 42

43 43 Micelles – lipid molecules orient with polar (hydrophilic) head toward water and nonpolar (hydrophobic) tails away from water

44 Phospholipid bilayer – more complicated structure where 2 layers form –Hydrophilic heads point outward –Hydrophobic tails point inward toward each other 44

Download ppt "Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. CHAPTER 3 LECTURE SLIDES To run the animations you must be."

Similar presentations

Ads by Google