Enzymes 2.1

Question 1

What is an active site?

Answer 1

Specific shape that will only allow complementary substrate to combine

Question 2

What reaction does lactase catalyse?

Answer 2

Lactose —> glucose + galactose

Question 3

What reaction does catalase catalyse?

Answer 3

Hydrogen peroxide —> water + oxygen

Question 4

What is the name of the process when enzymes combine things?

Answer 4

Anabolic

Question 5

What is the name of the process where enzymes break things apart?

Answer 5

Catabolic

Question 6

Why is the catabolic process important in digestion?

Answer 6

Breaks down substrate so they are small enough to be absorbed into blood stream

Question 7

As humans take in ready made nutrients what are they?

Answer 7

Heterotrophs

Question 8

As plants make own nutrients what are they?

Answer 8

Autotrophs

Question 9

What is the difference between intercellular and extracellular enzymes?

Answer 9

• intra=work in cell

- extra=work outside of cell

Question 10

What type of organisms have extracellular enzymes?

Answer 10

• fungi
• secrete enzymes (hyphae) digest foods around them
• absorbs monomers

Question 11

What is meant by the term endotherm?

Answer 11

Ability to regulate internal temperature (maintain and keep it consistent)

Question 12

What is activation energy?

Answer 12

Energy required to start a reaction

Question 13

What do enzymes do to activation energy?

Answer 13

Lower it

Question 14

What are the 2 types of models of how enzymes work?

Answer 14

• lock and key

- induced fit

Question 15

What is the lock and key method (enzymes)?

Answer 15

Complimentary substrate fits exactly into active site

Question 16

What is the induced fit model?

Answer 16

• active site moulds to substrate (not exactly complementary)
• can hold subtracts so it’s not released to early
• changes shape slightly after collision with substrate

Question 17

What is meant by kinetic energy?

Answer 17

Movement of molecules

Question 18

How does increasing the kinetic energy lead to faster reactions?

Answer 18

More collisions will happen

Question 19

What happens when temperature gets too high (enzymes)?

Answer 19

• hydrogen bonds wills break
• unravel and lose shape
• denatured

Question 20

How much can enzymes speed up reactions?

Answer 20

10^12

Question 21

What are characteristics of a catalyst?

Answer 21

• speed up chemical reactions and remain unchanged (able to use again)
• small amount can catalyse lots of reactions (substrate into product)

Question 22

What is a turn over rate?

Answer 22

Number of reactions per second am enzyme can catalyse

Question 23

What is a cofactor?

Answer 23

Substance that has to be present to ensure reaction happens at appropriate rate

Question 24

What are the 2 types of co-factors?

Answer 24

• prosthetic group=part of enzyme structure

- mineral ion / organic co-enzymes= form temporary associations

Question 25

What are prosthetic groups bought by?

Answer 25

Covalent bonds

Question 26

What are 2 ways that mineral ion cofactors work?

Answer 26

- them and substrate form correct shape to bind to enzymes active site - change charge distribution on surface (of substrate or enzymes active site) to make temporary bonds between enzyme and substrate easier to form

Question 27

What happens to co-enzymes during a reaction?

Answer 27

- chemically changed | - have to be recycled to original form (sometimes by a different enzyme)