Proteins

Question 1

functions of membrane proteins

Answer 1

1. receptor
2. binding site for hormones or neurotransmitters
3. channels for passive transport (“facilitated diffusion”)
4. pumps for active transport
5. cell adhesion
6. enzymes that are immobilized by being embedded in the membrane
7. electron transport and electron carriers

Question 2

factors that affect enzymes

Answer 2

1. collisions between enzyme/active site and substrate;
2. enzyme activity increases as temperature rises;
3. more frequent collisions at higher temperatures;
4. each enzyme has an optimum temperature / enzymes have optimal temperatures;
5. high temperatures (above optimum) denature enzymes;
6. each enzyme has an optimum pH / enzymes have optimal pHs;
7. increase or decrease from optimum pH decreases rate of reaction/activity;
8. extreme pH alters/denatures the tertiary/3D protein/enzyme structure;
9. increasing substrate concentration increases the rate of reaction;
10. higher substrate concentration increases chance of collision;
11. until plateau;
12. when all active sites are busy