The Chemical Building Blocks of Life

1. The Chemical BuildingBlocks of Life Lecture #3

2. Biochemicals • These chemicals are known as organic molecules. • Molecules – substances comprised of atoms. • Organic molecules – substances comprised mainly of carbon atoms. • Carbon atoms form the backbone of organic molecules.

3. Functional Groups • Various groups of molecules that attach to the carbon backbone • Hydroxyl • Carboxyl • Amino • Phosphate • Methyl

4. Major Classes ofOrganic Molecules Functional groups + carbon backbone = four major classes of organic molecules 1. Carbohydrates 2. Lipids 3. Proteins 4. Nucleic Acids

5. 1. Carbohydrates • Molecules that contain carbon (C), hydrogen (H) and oxygen (O) • CHO occurs in a ratio of 1:2:1 3. Glucose is a good example C6H12O6

6. Glucose

7. Same Formula – Different Molecule? • Other sugars have the same formula (C6H12O6) as glucose. • We call these molecules isomers. • Examples of isomers are fructose and galactose.

9. Sugars – Simple & Complex • Simple sugars (glucose) occur as single molecules called monosaccharides. • Simple sugar + simple sugar = disaccharide • Long chain of simple sugars = polysaccharide

10. Disaccharideglucose + fructose = sucrose

11. How do we link organicmolecules together?

12. How do we break apartcomplex organic molecules?

13. Polysaccharides

14. Function of Carbohydrates • Store energy – C-H bonds • Form structures

15. 2. Lipids 1.Lipids (fats) comprised of 2 components • Glycerol – 3 carbon backbone (C-C-C) • Fatty acids

17. Fatty Acids (Two Types)Saturated vs Unsaturated

18. Fatty Acids • All animal fats are saturated. • Most plant fats are unsaturated. • Fats serve the following purposes: A. Energy storage B. Cell membrane structure

19. 3. Proteins • Proteins are comprised of amino acids. AA—AA—AA—AA—AA—AA • There are 20 “common” amino acids. • All amino acids have the same formula: R H2N – C – C – OH H O

20. R-Groups

21. R-Groups (cont.)

22. How do we make proteinsfrom amino acids?

23. How do proteins differ? • Length – 100 to 6,000 AA long • Composition – ratio of the 20 AA • Sequence – order of the AA GLU—HIS—PRO HIS—PRO—GLU PRO—GLU—HIS

24. Roles of Proteins • Enzymes • Structural • Antibodies • Transport • Cell Recognition • Hormones

25. Protein Structure • Primary -- sequence of amino acids (AA) • Secondary -- interactions between AA • Beta-pleated sheets • Alpha helix

27. Protein Structure • Tertiary – folding of the protein • Quaternary – combining 2 proteins together

30. 4. Nucleic Acids • Information storage devices of the cell • They can replicate themselves. • They are hereditary molecules. • There are two types of nucleic acids: • DNA– double stranded • RNA – single stranded

31. Composition of Nucleic Acids 1. Long strands of subunits called nucleotides

34. Composition of a Nucleotide • Nucleotide – three components 1. Phosphate group

37. Composition of a Nucleotide • Nucleotide – three components 1. Phosphate group 2. A 5-carbon sugar

40. 5-Carbon Sugar • Two kinds of sugar 1. Deoxyribose -- found in DNA 2. Ribose – found in RNA

43. Composition of a Nucleotide • Phosphate radical • A 5-carbon sugar • A nitrogenous base

46. Two Types of Bases • Purines Adenine (A) and Guanine (G) Double Ringed • Pyrimidines Cytosine (C) Thymine (T) Uracil (U) Single Ringed

47. Purines and Pyrimidines

48. Base Distribution DNARNA Adenine + + Guanine + + Cytosine + + Thymine + -- Uracil -- +

49. DNA – double stranded • Base pairs A – T C – G • T – A – C – G – A – C • A – T – G – C – T – G