Enzyme precursors + activation

Question 1

What is the name of enzymes produced in an inactive form?

Answer 1

Inactive precursor enzymes

Question 2

What do inactive precursor enzymes prevent?

Answer 2

The enzyme carrying out its catalytic function before theyre released from cell via exocytosis

These precursor enzymes are called apoenzymes

Question 3

What happens for apoenzymes to turn into holoenzymes?

Answer 3

They bind to a cofactor and are activated

Question 4

How else can precursor enzymes be activated? And what are they called?

Answer 4

• By the action of another enzyme
• Environmental conditions that causes changes in tertiary structure

These types of precursors are called zymogens or proenzymes

Question 5

What happens in the chief cells of the stomach?

Answer 5

Pepsinogen is produced

Question 6

What happens once pepsinogen is secreted into the acidic pits of the stomach?

Answer 6

A small section is removed (removed peptide) and tertiary structure of enzyme changes

Question 7

What happens as a result of the tertiary structure of the enzyme changing?

Answer 7

Shape of active site becomes complimentary to the substrate (proteins) and pepsin becomes active

Question 8

Why are inactive precursor enzymes made?

Answer 8

So they dont break or cause damage to cell

Question 9

What is the equation for this process?

Answer 9

Inactive enzyme + cofactor -> Active enzyme