T2.5 Enzymes

Question 1

Enzymes

Answer 1

• Globular proteins that work as catalyst
• Polypeptide that takes on a very specific 3D shape

Question 2

Substrate

Answer 2

The thing getting broken down by the enzyme

Question 3

Active site

Answer 3

Area that is designed to match the substrate

Question 4

Enzyme-substrate specificity

Answer 4

Shape and chemical properties of active site/substrate match eachother
Interaction between charges on substrate and charges in active site

Question 5

What does enzyme catalysis involve?

Answer 5

Molecular motion and the collision of substrates with the active site

Question 6

Collisions (when dealing with enzymes)

Answer 6

The coming together of an enzyme and substrate

Question 7

Why do collisions occur?

Answer 7

A result of random molecular movement (Brownian Motion)

Question 8

Activation Energy

Answer 8

The amount of energy required to start a reaction

Question 9

Denaturation

Answer 9

When enzymes lose their native structure

Question 10

What conditions/factors can cause denaturation?

Answer 10

Temperature, pH, detergents, pressure, and salinity

Question 11

How does temperature effect enzymes?

Answer 11

• Higher temperature -> more kinetic energy -> more molecular collisions -> faster reaction rate
• When enzymes denature:
• Really high temperatures -> intermolecular bonds vibrate and break -> proteins lose shape (denatures) and no longer function

Question 12

Can you draw a graph of how temperature effects enzyme’s rate of reaction?

Answer 12

Link to graph
You better

Question 13

How does the pH effect enzymes?

Answer 13

• If too acidic: Positive hydrogen ions will bond with the negative charges of the substrate or enzyme, thus changing shape and losing function
• If too basic: Negative hydroxide (OH) ions will bond with positive charges of substrate or enzyme, thus changing shape and losing function

Question 14

Can you draw/recongize a graph of optimal pH’s of enzymes?

Answer 14

Link to graph
You better

Question 15

How is enzyme rate affected by substrate concentration?

Answer 15

More substrate -> more collisions -> more reactions

Question 16

What is the limitation of substrate concentration?

Answer 16

Enzymes have a max rate
(If theres 3 workers making sandwiches, they can only make 3 sandwiches at a time. If there are 50 people waiting for sandwiches, the max rate is still only 3)

Question 17

Saturation point

Answer 17

The point where the enzymes are working as fast as it can. (Where the rate plateaus)

Question 18

Can you draw a graph for increasing substrate concentration vs rate of reaction? Including saturation point??

Answer 18

Link to graph
You better

Question 19

Immobilized enzymes

Answer 19

When the enzymes are kept from moving, making them very stable.

Question 20

Advantages of immobilized enzymes

Answer 20

• Can easily be seperated from products of the reaction (stops reaction at ideal time)
• Can be recylced, saving costs
• Do not denature
• Increases stability to temperature and pH, reducing rate of denaturation and how ofter it needs to be replaced
• Substances can be exposed to higher enzyme concentrations, speeding up reactions

Question 21

Explain the use of lactase in the production of lactose-free milk

Answer 21

Companies culture yeast to purify lactase
Milk products can be treated with lactase before consumption so lactose intolerant people can absorb milk sugars because it is already broken down while the rest of the nutrients are not effected
Kilactic yeast converts the lactose to lactic acid