2. Chemical Reactions Process that changes set of chemicals into another set of chemicals Reactants yields Products 6CO 2 + 6H 2 0  C 6 H 12 O 6 + 6O 2 Slow Fast Metabolism: Chemical processes occurring within a living cell necessary to maintenance life Catabolism - Breaking Down molecules Anabolism – Building Molecules

3. Reaction Energy Energy is Released when chemical bonds Break Energy is Absorbed when chemical bonds Form Reactions that release energy Spontaneous Reactions that require energy Non Spontaneous

4. Energy requirements in chemical reactions Energy-Releasing Reaction Products Activation energy Reactants C 6 H 12 O 6 → CO 2 + H 2 O Burning a Log

5. Enzymes Chemical reactions in the human body require a lot of energy Enzymes serve as a CATALYST Speed up reactions that take place in cells

6. Reaction using Enzyme Candy Bar Reaction pathway without enzyme Activation energy without enzyme Activation energy with enzyme Reaction pathway with enzyme Reactants Products

7. CARBOHYDRATES

8. Characteristics of Carbohydrates Consist of carbon, hydrogen, & oxygen Energy containing molecules Some provide structure: Celulose Basic building block is a monosaccharide (CH 2 O) n ; n = 3,5,6 Two monosaccharides form a disaccharide

9. Three Monosaccharides C 6 H 12 O 6

10. Dehydration Synthesis of a Disaccharide

11. Formation of Disaccharides

12. Hydrolysis of a Disaccharide

13. Important Polysaccharides: Starch Consists of glucose subunits Plant energy storage molecule Glycogen is a very similar molecule in animals. Starch and glycogen can be digested by animals.

14. Important Polysaccharides: Cellulose Composed of glucose subunits Different bond formed than starch Structural component in plants Cannot be digested by animals

15. Important Polysaccharides: Chitin Glucose subunits Partly derived from non-sugars (nitrogen) Composes exoskeletons of insects Note similarity to cellulose.

16. LIPIDS

17. Characteristics of Lipids Composed of: Carbon, Hydrogen, and Oxygen Includes: Fats, Oils, Phospholipids, and Cholesterol Phospholipids part of cell membrane Building blocks: Fatty Acids and Glycerol. Energy storage molecules

18. Fatty Acid Structure Carboxyl group (COOH) forms the acid. “R” group is a hydrocarbon chain.

19. A Representative Fatty Acid

20. Saturated Fatty Acid Unsaturated Fatty Acid

21. Glycerol

22. Synthesis of a Fat

23. A Phospholipid

24. PROTEINS

25. Characteristics of Proteins Contain: Carbon, Hydrogen, Oxygen, Nitrogen, sulfur Function: Structural components of animals Control molecules (enzymes) Transport and messenger molecules Basic building block is the amino acid

26. Amino Acid Amine group acts like a base, tends to be positive. Carboxyl group acts like an acid, tends to be negative. “R” group is variable, from 1 atom to 20. Two amino acids join together to form a dipeptide. Adjacent carboxyl and amino groups bond together.

27. Some Amino Acids

28. Some More Amino Acids

29. Still More Amino Acids

30. Formation of a Dipeptide Dehydration synthesis

31. Amino Acid + Amino Acid --> Dipeptide Amino Acid + Dipeptide --> Tripeptide A.A. + A.A. + …..+ Tripeptide --> Polypeptide

32. A protein consists of one or more polypeptide chains.