Enzymes

Question 1

What is an anabolic reaction?

Answer 1

A reaction that uses smaller molecules to build a larger molecule

Question 2

What is a catabolic reaction?

Answer 2

A reaction that breaks down large molecules into smaller ones

Question 3

What is an interconversion?

Answer 3

It is a reversible reaction

Question 4

What is the Michaelis-Meanten model?

Answer 4

Shows the 1/2 Vmax of a enzy,e reaction.

Question 5

How does a competitive inhibitor change the rate, what does it change, Km or Vmax?

Answer 5

A competitive inhibitor increases Km, whilst Vmax stays constant

Question 6

How does a non-competitive inhibitor change the rate, what does it change, Km or Vmax?

Answer 6

A non-competitive inhibitor decreases Vmax, whilst Km remains constant.

Question 7

How can enzymes be regulated?

Answer 7

Temperature can either cause an enzyme to denature of freeze.
pH can denature a protein or can change the charge is a proton is gained or lost.

Question 8

What are the types of covalent regulation?

Answer 8

Cleavage - A zymogen (inactive enzyme) has a polypeptide chain blocking the active site. A protease cleaves the chain and activates the enzyme.

Phosphorylation - A kinase adds a phosphates to active the enzyme. A phosphatase removes the phosphate to inactive it again.

Question 9

What non-covalent regulation?

Answer 9

Allosteric enzymes have a binding site other than the active site (K type meaning it regulates the enzyme-substrate binding). Once it binds, it activates the enzyme to a higher affinity state. Alters Km

V-type changes the catalyitc step - Alters Vmax

Question 10

What is the effect of a competitive inhibitor?

Answer 10

It only affect binding, it causes a loss of binding which results in a HIGHER Km (Vmax stays constant).

Question 11

What is the effect of a non-competitive inhibitor?

Answer 11

It only affect the catalytic step, it causes a loss of catalysis which results in a LOWER Vmax (Km stays constant).