Unit 2 Metabolic Pathways

Question 1

Define metabolism:

Answer 1

Metabolism is the collective term for the many biochemical reactions that occur in a living cell

Question 2

What is a metabolic pathway?

Answer 2

Metabolic metabolic pathway is series of biochemical enzyme controlled reactions

Question 3

What are the three features of a metabolic pathway?

Answer 3

Irreversible, reversible, alternative route

Question 4

Explain why it is useful to be able to bypass steps in a metabolic pathway:

Answer 4

Alternative routes allow for fine control and prevent buildup’s and bottlenecks

Question 5

State to differences between catabolic an anabolic reactions:

Answer 5

Catabolic reactions breakdown molecules and release energy

anabolic reactions build up molecules and require energy

Question 6

Give an example of a catabolic reaction in a living thing:

Answer 6

Breakdown of pyruvate

Question 7

Give an example of an anabolic reaction in a living thing:

Answer 7

Muscle growth

Question 8

List four types of protein is found in the cell membrane:

Answer 8

Channel proteins
carrier proteins
receptors
enzymes

Question 9

What is the difference between protein pores and protein pumps?

Answer 9

Protein pores move molecules across the membrane by diffusion whereas pumps use active transport to transport molecules

Question 10

What is the name for the diagram of cells?

Answer 10

Fluid Mosaic model

Question 11

Give three reasons why enzymes are described as biological catalysts?

Answer 11

As the speeds up a chemical reaction
remain on changed by the reaction
lower activation energy

Question 12

How does an induced fit help to lower activation energy?

Answer 12

And induced fit applies pressure to the substrate due to a tight bind this tight bind that weekends chemical bonds

Question 13

Why do all living things need enzymes?

Answer 13

As to allow our fast reaction to take place it needs to happen at a high temperature cells can’t with stand high temperatures so something else is needed with enzymes reactions can happen at a low temperature therefore not denaturing the cells

Question 14

What does affinity mean?

Answer 14

Chemical attraction

Question 15

What is the difference between the affinity of the active site for the substrate and for the product?

Answer 15

Affinity of active site for the substrate is high where as the affinity of the active site for the product is low

Question 16

List three factors that can affect the rate of an enzyme controlled reaction:

Answer 16

Temperature
PH
substrate concentration

Question 17

What determines the structure of an Enzymes active site?

Answer 17

Sequence of amino acids

Question 18

Why can’t the enzymes rate of reaction increases past a certain point even so more substrate is being added?

Answer 18

Enzymes rate of reaction can’t increase as all the active site are being occupied by the substrate
by adding more you are not going to get the enzymes to work faster

Question 19

How could you increase the reaction past the rate that the enzymes work at?

Answer 19

By adding more enzymes

Question 20

Explain how metabolic pathways can be controlled by genes?

Answer 20

By switching genes on and off that control enzyme production

Question 21

Why is it useful to control pathways in this way by Switching enzyme production on an off?

Answer 21

As it allows for enzymes to operate for and backwards and prevents waste

Question 22

What is an inhibitor:

Answer 22

it reduces the rate of an enzyme controlled reaction

Question 23

What is the end product inhibition and how does it work?

Answer 23

When the pathway of the product reaches a certain concentration this then means that the end product inhibit an earlier enzyme and blocking the pathway

Question 24

What is the benefit of end product inhibition?

Answer 24

Useful as a prevents Wasteful accumulation or conversion of intermediates

Question 25

What is competitive inhibition?

Answer 25

Competitive inhibition is when it competes with the substrate for the active site

Question 26

How can you reverse competitive inhibition?

Answer 26

By increasing substrate concentration

Question 27

What is non-competitive inhibition?

Answer 27

Non-competitive inhibition is when attaches to a non-active (allosteric) site and change the shape of the enzyme molecule Indirectly altering the shape of enzymes active site so the substrate cannot bind and the rate of reaction decreases

Question 28

Can the effect of non-competitive inhibition be reversed by increasing substrate concentration?

Answer 28

No

Question 29

Activation energy:

Answer 29

The energy required for a reaction to take place