1.6

Question 1

What are Metabolic pathways

Answer 1

Metabolic pathways are integrated and controlled pathways of enzyme-catalysed reactions within a cell.
Metabolic pathways can have reversible steps, irreversible steps and alternative routes.
They fall under 2 categories:
Catabolic pathways
Anabolic pathways

Question 2

What are Catabolic Pathways

Answer 2

Catabolic pathways breakdown complex molecules into simpler ones, usually involving the release of energy - aerobic respiration

Question 3

What are Anabolic Pathways

Answer 3

Anabolic pathways involve the build up of complex molecules from simple molecules, this usually requires energy - protein synthesis

Question 4

What is meant by Induced Fit

Answer 4

Induced fit occurs when the active site changes shape to better fit the substrate after the substrate binds
The substrate molecule(s) have a high affinity for the active site and the products have a low affinity allowing them to leave the site.

Question 5

What are Competitive Inhibitors

Answer 5

Competitive inhibitors bind at the active site preventing the substrate from binding
Competitive inhibition can be reversed by increasing substrate concentration

Question 6

What are Non-competitive Inhibitors

Answer 6

Non-competitive inhibitors bind away from the active site but change the shape of the active site preventing the substrate from binding. Non-competitive inhibition cannot be reversed by increasing substrate concentration.

Question 7

What is Feedback Inhibition

Answer 7

Feedback inhibition occurs when the endproduct in the metabolic pathway reaches a critical concentration. The end-product then inhibits an earlier enzyme, blocking the pathway, and so prevents further synthesis of the end-product.