enzymes

Question 1

what is an enzyme

Answer 1

a biological catalyst that speeds up the rate of reaction without being used up itself

Question 2

lock & key enzyme method:

Answer 2

1. the substrate collides with the active site and forms enzyme substrate complex
2. the enzyme catalyses the substrate
3. products are released from the active site
4. enzyme remains unchanged so can be reused

Question 3

four factors that affect the activity rate of enzymes:

Answer 3

1. temperature
2. pH
3. substrate concentration
4. enzyme concentration

Question 4

what happens as enzymes and substrates are heated?

Answer 4

• rate of reaction increases
• molecules have more kinetic energy, so move faster
• more collisions

Question 5

what happens when enzymes are heated past their optimum temp?

Answer 5

they denature
- heat causes the amino acids in the enzyme to unfold so it changes its structure
- the substrate molecules can no longer fit in the active site

Question 6

optimum pH in the stomach

Answer 6

pH2

Question 7

optimum pH in the small intestine

Answer 7

pH7

Question 8

what happens if the enzyme/substrate concentration becomes too high

Answer 8

will become saturated so ROR will plateau