Enzymes

Question 1

Enzyme

Answer 1

An organic molecule, typically a protein, that catalyses (speeds up) specific reactions.

Question 2

Catalyst

Answer 2

A substance capable of increasing the rate of a reaction without being used up.

Question 3

Catalyse

Answer 3

To increase the rate of a reaction

Question 4

Substrate

Answer 4

The reactant of a reaction catalysed by an enzyme.

Question 5

Reactant

Answer 5

A molecule that undergoes a transformation into a product. When enzymes are involved, the reactant is called a substrate.

Question 6

Product

Answer 6

The transformed molecule created in a reaction.

Question 7

Active site

Answer 7

The part of an enzyme where the substrate binds

Question 8

Enzyme-substrate complex

Answer 8

The structure formed when an enzyme and a substrate are bound together.

Question 9

Conformational change

Answer 9

A change in the 3D shape of macromolecules such as proteins.

Question 10

Activation energy

Answer 10

The energy required to initiate a reaction.

Question 11

Collision theory

Answer 11

Explanation of chemical reactions that states that in order to react molecules must hit one another.

Question 12

Biochemical pathway

Answer 12

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

Question 13

Optimal

Answer 13

The point at which for a given condition (e.g. temperature), the maximum function of an enzyme occurs. AKA optimum

Question 14

Denature

Answer 14

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

Question 15

Saturation point

Answer 15

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

Question 16

Limiting factor

Answer 16

A factor that prevents the rate of reaction from increasing.

Question 17

Limiting reagent

Answer 17

A reactant that prevents the rate of reaction from increasing.

Question 18

Enzyme inhibitor

Answer 18

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

Question 19

Competitive inhibition

Answer 19

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

Question 20

Non-competitive inhibitor

Answer 20

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 21

Allosteric site

Answer 21

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

Question 22

Reversible inhibition

Answer 22

Enzyme inhibition that involves weaker bonds that can be overcome.

Question 23

Irreversible inhibition

Answer 23

Enzyme inhibition that involves stronger bonds that cannot be broken.

Question 24

Cofactor

Answer 24

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

Question 25

Coenzyme

Answer 25

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

Question 26

ATP - adenosine triphosphate

Answer 26

A high energy molecule that, when broken down, provides energy for cellular processes.

Question 27

ADP - adenosine diphosphate

Answer 27

The unloaded form of ATP.