1.4 Biological Reactions Are Regulated By Enzymes

Question 1

Enzymes are….?

Answer 1

• Biological catalysts
• Globular proteins
• Fast acting
• Affected by inhibitors
• Affected by temperature and pH
• Specific

Question 2

Enzyme structure functions

Answer 2

1. Tertiary structure
2. Hydrophilic r group ok outside of molecule
3. Enzyme are soluble
4. Have a particular sequence of amino acids
5. Each enzyme has a small area with a specific 3d shape - the active site
6. The active site shape can denature - changes shape

Question 3

What is extracellular - site of enzyme action

Answer 3

Happens outside cells
Amylase - our of glands to mouth
Serotonin fungi and bacteria - secrete enzyme on to food

Question 4

What is intracellular (in solution) - site of enzyme action

Answer 4

Breakdown of glucose in glycolysis
Storms of the chloroplasts that catalyse the synthesis of glucose

Question 5

Intercellular (membrane bound) - site of enzyme action

Answer 5

Transfer electrons and hydrogen ions in ATP formation

Question 6

Explain about the active site of the enzyme substrate complex

Answer 6

An enzyme acts on its substrate with which it makes temporary bonds, at the active site, forming an enzyme substrate complex

Question 7

What happens when the reaction is complete in the active site

Answer 7

Products are released, leaving the enzyme uncharged and the active site ready to revive another substrate

Question 8

What is the lock and key model

Answer 8

• unique shape of the active site means that an enzyme can only catalyse one type of reaction
• the substrate is imagined fitting into the active site as a key fits into a lock
• the shapes of the lock and key are specific to each other

Question 9

What is the induced fit theory

Answer 9

• Suggests the enzymes shape alters slightly to accommodate the substrate
• the active site is able to mould itself around the substrate

Question 10

What are the stages of the induced fit theory

Answer 10

1. Sugar enters groove
2. Groove closes over sugar
3. Lysosomes changes shape around sugar
4. Bond holding sugar together are hydrolysis

Question 11

What is the elements before the arrow in a chemical reaction called

Answer 11

Reactants

Question 12

What is the elements after the arrow called

Answer 12

Products

Question 13

What is the collision theory

Answer 13

For a chemical reactions to occur the reactant particles must collide with each other

Question 14

Define activation energy

Answer 14

The minimum amount of energy for a collision to be successful is called the activation energy

Question 15

What factors effect enzyme activity

Answer 15

Temperature
pH
Substrate concentration
Enzyme concentration
Inhibitors