Enzymes

Question 1

What are enzymes?

Answer 1

biological catalysts that speed up the rate of reaction and remains unchanged and reusable at the end of the reaction.

Question 2

How do enzymes increase the rate of reaction

Answer 2

They lower the activation energy of the reaction.

Question 3

What is the lock and key model?

Answer 3

proposed that each substrate is a key that only fits a specific lock or enzyme.

Question 4

What is the induced fit model?

Answer 4

See photo

the active site of the enzyme is changed slightly to better fit the substrate after the substrate binds

Question 5

How is enzyme specificity attchived?

Answer 5

due to the tertiary structure of its active site, allowing complementary binding to substrates.

Question 6

Enzymes catalyse both ______and ________reactions that determine structures and functions from cellular to whole organism level

Answer 6

intracellular extracellular

Question 7

Catalase intracellularly example

Answer 7

breaks down hydrogen peroxide into water and oxygen

Question 8

Catalase extracellularly examples (2 examples)

Answer 8

Amylase is secreted from the salivary glands and pancreas to extracellularly break down starch. Requires Cl– cofactor Trypsin is secreted from the pancreas to extracellularly break down proteins

Question 9

Some enzymes are synthesised in an inactive precursor form and need to be activated. What does this mean?

Answer 9

another enzyme removes part of the molecule in trypsin, forming the correct active site shape

Question 10

Some enzymes require a cofactor. What does this mean?

Answer 10

a substance which must be present to enable an enzyme to catalyse a reaction at the appropriate rate.

a non-protein chemical compound that tightly and loosely binds with an enzyme or other protein molecules

Question 11

Examples of cofactors?

Answer 11

A prosthetic group is permanently bound A coenzyme forms temporary associations and are derived from vitamins

Question 12

Examples of a prosthetic group

Answer 12

Zn2+ bound to carbonic anhydrase

Question 13

Factors affecting enzyme activity include:

Answer 13

pH Temperature Enzyme concentration substrate concentration Competitive & non-competitive inhibitor concentration

Question 14

Competitive & non-competitive inhibitor concentration diagrams

Answer 14

see photo

Question 15

What is the temperature coefficient (Q10)

Answer 15

theeffect of a 10°C rise in temperature on the rate of the reaction

Question 16

Q10 formula

Answer 16

see photo