C5- Enzymes

Question 1

Enzyme

General definition

Answer 1

Globular proteins that act as a biological catalyst

They catalyse reactions that affect metabolism

Lower activation energy needed for a reaction to begin

Question 2

Metabolism

Answer 2

All the chemical reaction in a cell

catabolism= breaking down
large -> small

Anabolism= Building up
small –> large

Question 3

Extracellular enzymes

Answer 3

Their effect is outside the cells that produce them

e.g. amylase

Question 4

Intracellular enzymes

Answer 4

Their effect is inside the cells that produced them

e.g. Catalase
–> catalyses hydrolysis of hydrogen
peroxide

Question 5

Lock and key hypothesis

Answer 5

enzyme has an area called the active site that is complimentary to the shape of the substrate

When bound this forms the enzyme substrate (e-s) complex

substrate then reacts and the product or products are formed

This forms the enzyme product (e-p) complex

Substrate is held in such a way by the enzyme that the right R groups are close enough to react. Temporary bonds form between enzyme and substrate, putting strain on the bonds in the substrate which helps the reaction along

Question 6

Induced fit hypothesis

Answer 6

modified version of lock and key hypothesis, where initially the substrate is not complimentary to the active site.

When the enzyme substrate (e-s) complex is formed the enzyme changes shape slightly as the substrate binds to the enzyme,

allowing the reaction to take place due to lowered activation energy

Question 7

Active site

Answer 7

part of the protein molecule with the specific 3D shape to bind to one specific complimentary substrate

Question 8

Substrate

Answer 8

A substance used or acted on by a process or enzyme