2. Aim: What are the building blocks of proteins?

3. Building Blocks: Amino Acids = Central Carbon

4. Amino Acids ValineAlanine Glycine Q: How are these amino acids similar? How do they differ?

5. What are proteins? Proteins ALWAYS contain the following atoms: Nitrogen (N) Carbon (C) Hydrogen (H) Oxygen (O) Note: sometimes they also contain sulfur & phosphorus Many kinds of proteins exist, each with different properties.

6. Why do we need them? Found throughout living organisms. Structural parts of cells and body tissues (bone, muscle, & cartilage). Hormones- chemical messengers that control body functions. Example: Insulin- a hormone that regulates glucose levels Found in antibodies (our defense against disease). Enzymes- “special” proteins that allow complex chemical reactions to occur faster.

7. 20 Different Amino Acids ONLY Side chains (R) differ Amino Acid Structure:

8. Dehydration Synthesis H 2 O Removed To link amino acids together.

9. Dehydration Synthesis (Another look)

10. Hydrolysis Water is added (hydro-) which breaks the peptide bond (-lyse)

11. Proteins RNA- contains the information to make proteins. Q: What kind of organic compound is RNA? The order of amino acids in a polypeptide chain determines the type of protein that is formed. Different order of amino acids = different proteins Note: Proteins are NOT really square, circular, etc. The different shapes are used to represent different amino acids.

12. Enzymes INCREASE the rate (speed) of chemical reactions within living cells. Many enzymes are proteins. By lowering the energy needed to start a chemical reaction (activation energy). They hold molecules close together and in the right orientation so molecules don’t need to rely on random collisions.

13. Many Enzymes With Specific Names End in “-ase.” The rest of the name usually comes from the name of the substrate being acted on. SubstrateEnzymeFunction Malt oseMalt ase Breaks down malt ose (disaccharide) into two glucose (monosaccharide) molecules Sucrose Sucr ase Breaks sucr ose (disaccharide) into glucose and fructose (both monosaccharides) Starch Amyl ase Breaks down starch (polysaccharide) into maltose (in saliva) Proteins Prote ase Break down proteins LipidsLip ase Break down lipids

14. Enzymes They are catalysts (speed up reactions without being changed or destroyed). Act on specific substances called substrates. Each type of enzyme has a unique 3D shape which determines the substrate it can bind to.

15. Enzymes and homeostasis Without enzymes, reactions would not happen fast enough to support life of an organism.

17. Enzyme-Substrate Complex Substrate fits into a region of a specific enzyme called the enzyme’s active site. Very specific (like a lock & key). In the active site, bonds are formed/broken in the substrate(s) to make a product.

18. Enzyme Action Q: Is a bond formed or broken to create the product seen above?

19. Enzyme Action

20. Identify the enzyme and substrate in the example below.

21. Three Factors affecting enzymes 1. Temperature 2. pH 3. Substrate concentration (amount of substrate)

22. STOP