6.4.3: Enzymes

Question 1

Enzymes

Answer 1

Speed up reactions by acting as biological catalysts.

Question 2

Substrates

Answer 2

The molecules that enzymes act upon.

Question 3

Active site

Answer 3

An area of an enzyme that the substrate fits into so it can interact with the enzyme and is 3D.

Question 4

Model that explains enzyme specificity

Answer 4

the lock and key model

Question 5

Stereospecific

Answer 5

The active site of an enzyme will only work on one enantiomer of a substrate.

Question 6

Inhibitors

Answer 6

Molecules that have a similar shape to the substrate so can block the active site so no substrate can fit.

Question 7

The amount of inhibition depends on

2 factors

Answer 7

• relative concentrations of enzyme and substrate

- how strongly the inhibitor bonds to the active site

Question 8

Inhibitors can be used as

Answer 8

drugs

Question 9

How can the slow process of finding the effectiveness of drugs be sped up?

Answer 9

Use computers to the model the shape of the enzyme’s active site and predict how well potential drug molecules will interact with it.

Question 10

Why is it difficult to find drug molecules that will fit enzymes’ active sites?

Answer 10

• the active site is very specific, so need a drug that will fit it
• more difficult if the drug molecule is chiral as only one enantiomer will fit the active site

Question 11

How do antibiotics work as inhibitors?

Answer 11

Block the active site of an enzyme in bacteria that helps to make their cell walls,
causes their cell walls to weaken overtime and eventually burst