enzymes

Question 1

define catalyst

Answer 1

• substance that increases rate of a chemical reaction
• and isn’t changed by the reaction

Question 2

define enzymes

Answer 2

• proteins involved in all metabolic reactions
• where they function as biological catalysts

Question 3

Describe why enzymes are important in all living
organisms

Answer 3

Speed up biochemical reactions
- High reaction rate necessary to sustain life

Question 4

Explain enzyme-action

Answer 4

Shape of an active site of an enzyme is complementary to its substrate.
* Each enzyme is only able to act on a specific substrate (Enzyme specificity)

When the substrate is in the active site & bound to t he enzyme, the enzyme makes the substrate change into a product.
* Enzyme-substrate complex occurs.
* Product then breaks away from enzymes. Enzymes ready to bind w another substrate.

Question 5

Factors affecting enzymes
Explain the effect.

Answer 5

Temperature
* higher temp increases rate of reaction, only up to an optimum temp when enzyme is most active.
* as temp increases, enzymes have more kinetic energy, so collide w each other more & faster, there’s high frequency of effective collisions.

after optimum temp, rate of reaction decreases.
* higher temp denatures active site of enzyme; no longer complementary to substrate.
* enzyme substrate complex unable to take place.

pH
* each enzyme works at optimum pH
* pH above/below causes enzyme active site to denature; enzyme-substrate complex no longer being able to take place

Question 6

state the enzymes that catalyze the breakdown of:
1. carbohydrates
2. proteins
3. lipids
4. starch
5. maltose
6. sucrose
7. hydrogen peroxide

Answer 6

1. carbohydrases
2. proteases
3. lipases
4. amylase = to maltose
5. maltase = to glucose
6. sucrases
7. catalase = water + oxygen