Enzyme Test

Question 1

What are enzymes

Answer 1

Special proteins that control chemical reactions in living systems
Biological catalysts
Allow reactions to occur with less activation energy

Question 2

How do enzymes work?

Answer 2

Use a lock and key mechanism
Enzymes are substrate specific
Are not consumed and can be reused

Question 3

What are two types of reactions

Answer 3

Catabolic

Anabolic

Question 4

What is a catabolic

Answer 4

Breakdown
Large molecules broken into smaller molecules
Usually exothermic

Question 5

What does exothermic mean

Answer 5

Release energy

Question 6

What does Anabolic do

Answer 6

Building
Small molecules are combined
Usually endothermic

Question 7

What does endothermic mean

Answer 7

Brings in energy

Question 8

What is metabolism

Answer 8

Sum of energy related reactions in a living system

In humans metabolism overall produces heat

Question 9

What is Thyroxin

Answer 9

A hormone from the thyroid gland that is used to regulate overall metabolism

Question 10

What is iodine

Answer 10

Required to make Thyroxin

Question 11

What are 4 factors that affect enzyme activity

Answer 11

1) temperature
2) pH
3) Concentration
4) Inhibitors

Question 12

At what temperature does enzymes do their thing

Answer 12

0-38 enzyme activity increases with temperature as the molecules are moving faster with more energy
38-40 maximum temp for enzyme activity
44+ protein enzymes begins to denature

Question 13

pH

Answer 13

Each enzyme has a specific pH where it works best (optimum)
Most enzymes work over a narrow range of pH
Small changes in pH can denature enzyme

Question 14

What are buffers

Answer 14

Used to maintain a constant pH

Question 15

Concentration

Answer 15

More enzyme=more reactions (unlimited substrate)=straight line upwards

Substrate
Adding substrate increases enzyme activity
At Saturation Point all enzymes are working at maximum rate (graph levels off)

Question 16

What is Saturation Point

Answer 16

All enzyme molecules are working at maximum speed so adding more substrate makes no difference

Question 17

Inhibitors

Answer 17

Only found in organic chemistry
On and off switches
Molecules that prevent substrate joining with the enzyme at the active site

Question 18

What are the 3 types of inhibitors

Answer 18

1) competitive
2) noncompetitive
3) reversible

Question 19

Competitive

Answer 19

Join to active site and block the substrate

Question 20

Noncompetitive

Answer 20

Inhibitor attaches to a different part of the enzyme (not the active site)

Question 21

Reversible

Answer 21

Does not attach permanently to enzyme
Enzyme function is slowed down not stopped
Often used in living systems
Product of a reaction often act as inhibitors
Negative feedback

Question 22

What does Negative Feedback when talking about Reversible Inhibitors

Answer 22

Keeps level of product constant

Question 23

What are metabolic pathways

Answer 23

Most enzymes do not work alone

Enzymes work together in sequence the product of one reaction becomes the substrate of the next