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Question 1

What are metabolic pathways?

Answer 1

They are integrated and controlled pathways of enzyme-catalysed reaction within a cell.

Question 2

Do metabolic pathways have reversible steps?

Answer 2

They can have reversible steps, irreversible steps and alternative routes.

Question 3

How are metabolic pathways helpful by having reversible/irreversible steps and alternative routes?

Answer 3

They help make sure a steady supply of products or make sure that too many products are not produced.

Question 4

What is an anabolic reaction?

Answer 4

Build up large molecules from small molecules, require energy.

Question 5

What is a catabolic reaction?

Answer 5

Break down large molecules into smaller molecules, release energy.

Question 6

What is needed to carry out any enzyme reaction?

Answer 6

energy input.

Question 7

What is the energy required for a reaction to occur known as?

Answer 7

activation energy.

Question 8

What happens when enzymes lower activation energy?

Answer 8

making it more likely a reaction will occur, increasing reaction rate.

Question 9

What is an induced fit?

Answer 9

when a complementary substrate enters the active site of an enzyme, the active site changes shape to better fit the substrate.

Question 10

What does an induced fit do to the reaction?

Answer 10

Lowers the activation energy for the reaction to occur.

Question 11

Substrates have ______ for the active site of an enzyme, meaning ______

Answer 11

high affinity, meaning that they move easily into the active site.

Question 12

Products have _____ for the active site, meaning _______

Answer 12

low affinity, meaning that they move out of the active site, freeing it up for more reaction to occur.

Question 13

What is enzyme activity affected by?

Answer 13

temperature, pH, substrate concentration and product concentration.

Question 14

What happens when low concentration of substrate is present?

Answer 14

Enzyme activity is low due to the low number of interactions betweens substrates and enzymes. Both substrate concentration and enzyme activity increase due to increasing interaction between enzymes and substrates. Enzyme activity stops increasing due to enzyme active sites being occupied, no longer being able to carry out a faster reaction.

Question 15

How do enzymes [prevent over-production of a product?

Answer 15

some enzymes work in reverse direction if product concentration is far too high.

Question 16

Are enzymes affected by product concentration?

Answer 16

Yes, as product concentration increases, enzymes activity decreases.

Question 17

What are enzyme inhibitors?

Answer 17

They are inhibitors that block or reduce the action go enzymes.

Question 18

What are the three types of enzyme inhibitors?

Answer 18

competitive inhibitors, non-competitive inhibitors and feedback inhibitors.

Question 19

How do competitive inhibitors block or reduce the action of enzymes?

Answer 19

by binding at the active site preventing the substrated from binding.

Question 20

Can competitive inhibitors be reversed?

Answer 20

yes, by increasing substrate concentration.

Question 21

How do non-competitive inhibitors block or reduce the action fo enzymes?

Answer 21

by binding away from the active site but change the shape of the active site preventing substrate from binding.

Question 22

Is non-competitive inhibition reversable?

Answer 22

no, cannot be reversed by increasing substrate concentration.