Enzymes

Question 1

What are enzymes?

Answer 1

Large, globular proteins which act as Catalysts in metabolism

Question 2

What 2 theories are used to explain how enzymes work?

Answer 2

Lock and key
Induced fit

Question 3

What does induced fit suggest about the active site of an enzymes?

Answer 3

The active site alters its shape to be complement to the substrate

Question 4

What is an enzyme substrate complex?

Answer 4

When the tertiary structure of the active site successfully binds to the substrate

Question 5

How many reactions can an enzyme catalise and why?

Answer 5

Many as they are not permenantly damaged

Question 6

What are intracellular enzymes? Give an example

Answer 6

Enzymes that work inside cells.
Catalase breaks down into hydrogen peroxide and water in the liver

Question 7

What are extra cellular enzymes? Give an example

Answer 7

Enzymes that work outside of cells.
Trypsin breaks down proteins in the small intestine

Question 8

How does temperature effect enzyme reactivity?

Answer 8

Enzymes and substrates gain kinetic energy and so collide more creating more enzyme substrate complexes

Question 9

What happens if the temperature is above optimum on enzymes?

Answer 9

The enzymes tertiary structure denatures

Question 10

What is the temperature coefficient and what is the equation?

Answer 10

The increase in rate of reaction as a result of increasing the temperature by 10 degrees celsius.

Q10 = R2 ÷ R1

Question 11

What graph shape is made during enzyme reactions?

Answer 11

Bell curve

Question 12

Describe the effect of PH on enzyme reactivity

Answer 12

Any movement away from optimum PH causes their to be an unbalanced level of H+ ions which causes the tertiary structure of the active site to denature

Question 13

What is the PH of HCl

Answer 13

1 or 2

Question 14

What does pepsin break down?

Answer 14

Large proteins in the stomach

Question 15

What does pancreatic juice contain?

Answer 15

Trypsin madd in the gall bladder is alkali of 7.8

Question 16

What is a limiting factor?

Answer 16

Something which prevents a reaction from continuing

Question 17

What does inhibition mean?

Answer 17

Stop / prevent

Question 18

What does inhibition mean?

Answer 18

Stop / prevent

Question 19

What is a competitive inhibitor?

Answer 19

Something that is also complementary to the active site but is not the substrate. They slow reactions but eventually reach v-max

Question 20

What is a non competitive inhibitor?

Answer 20

Something which binds to an alloseric site on the enzyme altering the shape of the active site so it is no longer complementary to the substrate. Doesn’t reach v-max

Question 21

What is end product inhibition?

Answer 21

When the product can stop or enhance production based on how much has already been produced

Question 22

What is a cofactor, coenzyme and prosthetic group?

Answer 22

Cofactor: inorganic protein bound to substrate

Coenzyme: organic protein bound to substrate

Prosthetic group: can be co factors or co enzymes

Question 23

What is a holoenzyme?

Answer 23

An enzyme containing a co factor or co enzymes

Question 24

What is a holoenzyme?

Answer 24

An enzyme containing a co factor or co enzymes