Enzymes!!

Question 1

define an enzyme

Answer 1

globular protein
biological catalysts
speed up a rate of a reaction

Question 2

define anabolic

Answer 2

this type of pathway requires energy and is used to build up large molecules from smaller ones

Question 3

define catabolic

Answer 3

this type of pathway releases energy and is used to break down large molecules into smaller ones

Question 4

define activation energy

Answer 4

energy needs to be supplies to start a reaction

Question 5

describe and explain the lock and key hypothesis

Answer 5

the substrate binds to the active site forming an enzyme-substrate complex
the substrate then reacts and the products are formed in an enzyme-product complex
substrate has complementary shape to its active site

Question 6

describe and explain the induced fit hypothesis

Answer 6

when the substrate binds to the active site, the tertiary structure of the enzyme slightly changes this is due to the weak interactions between the enzyme and substrate
this strengthens binding putting a strain on the substrate molecule

Question 7

what are the two types on enzymes

Answer 7

intracellular

extracellular

Question 8

describe and explain intracellular

Answer 8

enzymes that act within cells are called intracellular enzymes
hydrolytic enzymes

Question 9

describe and explain extracellular

Answer 9

enzymes that work outside the cell

Question 10

what are coenzymes

Answer 10

Coenzymes are organic cofactors which do not bind permanently. They facilitate the
binding of substrate to enzyme. Many coenzymes are vitamin derived, examples include
NAD derived from niacin, which acts as a hydrogen acceptor.

Question 11

what are coefactors

Answer 11

A cofactor is a non-protein compound required for the enzyme’s activity to occur. There
are three types of cofactors: coenzymes, activators and prosthetic groups.

Question 12

what are activators

Answer 12

Activators are inorganic metal ions which temporarily binds to the enzyme and alters its
active site, making the reaction more feasible. For instance, magnesium ion is an important
activator which is involved in processes such as shielding negative charge.

Question 13

what are prosthetic groups

Answer 13

Prosthetic groups are permanently attached to the enzyme. For instance, haemoglobin
contains a prosthetic haem group which contains iron, permanently bound to the molecule,
which serves as a means of binding oxygen.

Question 14

what is the precursor before and after the enzyme reaction

Answer 14

it is called an apoenzyme and after the coefactor and the enzyme is activated is added it is called a halo-enzyme

Question 15

what happens when the enzyme has been denatured

Answer 15

vibrations increase until the bonds strain and then break
tertiary structure of the enzyme changes
active site is no longer complementary to the substrate
enzyme will no longer function as a catalyst

Question 16

what is renaturation

Answer 16

when the pH returns to the optimum then protein will resume its normal shape and catalyse the reaction