3B: Factors that affect enzymes

Question 1

Optimal

Answer 1

The point at which for a given condition the maximum function of an enzyme occurs.

Also known as optimum.

E.g. temperature

Question 2

Denature

Answer 2

The disruption of a molecule’s structure by an external factor such as heat.

Question 3

Conformational change

Answer 3

A change in the three-dimensional shape of macromolecules such as proteins.

Question 4

Saturation point

Answer 4

The point at which a substance (e.g. an enzyme) cannot receive more of another substance (e.g. a substrate).

Question 5

Limiting factor

Answer 5

A factor that prevents the rate of reaction from increasing.

• e.g. number of enzymes

Question 6

Enzyme inhibitor

Answer 6

A molecule that binds to and prevents an enzyme from functioning.

Question 7

Competitive inhibition

Answer 7

The hindrance of an enzyme by blocking the active site and preventing the substrate from binding.

Question 8

Non-competitive inhibition

Answer 8

The hindrance of an enzyme by binding to an allosteric site and changing the shape of the active site to prevent the substrate from binding.

Question 9

Allosteric site

Answer 9

A region on an enzyme that is not the active site.

Question 10

Biochemical pathway

Answer 10

A series of enzyme-catalysed biochemical reactions in which the product of one reaciton becomes the substrate of the next reaction. AKA the metabolic pathway.

Question 11

Cofactor

Answer 11

Any organic or inorganic molecule, such as a coenzyme or metal ion, that assists enzyme function.

Question 12

Coenzyme

Answer 12

A non-protein organic cofactor that assists enzyme function. They released energy and are recycled during a reaction.

Question 13

ATP

Answer 13

Adenosine triphosphate, a high energy molecule thatm when broken down, provides energy for cellular processes.

Question 14

ADP

Answer 14

Adenosine diphosphate, the unloaded form of ATP