Factors Affecting Enzyme Reaction

Question 1

What are the factors of enzyme reaction

Answer 1

Temperature,pH,enzyme concentration,substrate concentration

Question 2

What happens in an enzyme-controlled reaction when the temperature increases

Answer 2

The rate of an enzyme controlled reaction increase

Question 3

What does more heat mean

Answer 3

More kinetic energy which results in molecules moving faster

Question 4

What are the enzymes more likely to do the faster they move

Answer 4

They are more likely to collide with the substrate molecules

Question 5

What increases with the collision apart from rate when temp. Increases

Answer 5

Energy of collision which means each collision is more likely to result in a reaction

Question 6

What happens if the energy is too high

Answer 6

The reaction stops and the enzyme denatures

Question 7

What happens to the bonds if the temperature goes above a certain point

Answer 7

The vibration of molecules breaks some of the bonds that holds the enzyme in shape

Question 8

What happens if the active site changes shape

Answer 8

The enzyme and the substrate no longer fit together

Question 9

At what point does the enzyme no longer work as a catalyst

Answer 9

When It denatures

Question 10

What pH do most human enzymes work at

Answer 10

Ph7

Question 11

What enzymes are exceptions of the average pH level

Answer 11

Pepsin,which is optimum at pH2

Question 12

Why is pepsins low pH useful

Answer 12

It can be found in the stomach

Question 13

Above and below the pH,the H+ and OH- found in acids and alkalis mess up _______

Answer 13

Ionic bonds and hydrogen bonds that hold the enzymes tertiary structure

Question 14

What happens the more enzyme molecules there are in a solution

Answer 14

The more likely a substrate molecule is to collide with one and form an enzyme substrate complex

So increasing the concentration increases the rate of reaction

Question 15

What happens if the substrate is limited

Answer 15

There comes a point when there’s more than enough enzyme molecules to deal with all the available substrate, so adding more enzyme has no further affect

Question 16

What happens the higher the substrate concentration is

Answer 16

The faster the reaction,more substrate molecules means a collision between substrate and enzyme is more likely and so more active sites will be used

Question 17

What is the saturation point

Answer 17

The point at which so many substrate molecules are present that the active sites are all full so adding more will have no effect

Question 18

Why is the initial rate if reaction the highest rate of reaction

Answer 18

As the reaction will always decrease unless substrates are added

Question 19

Enzymes can be prevented by _______

Answer 19

Enzyme inhibitors

Question 20

What are inhibitors

Answer 20

Molecules that bind to the enzyme that they inhibit .

Inhibition can be competitive or non-competitive

Question 21

What do competitive inhibitors have a similar shape to

Answer 21

Substrate molecules

Question 22

What do competitive inhibitors do?

Answer 22

They compete with the substrate molecules to bind to the active site,but no reaction takes place

Instead they block the active site,so no substrate molecules can fit in it

Question 23

What does how much the enzyme inhibits depend on

Answer 23

The relative concentrations of the inhibitor and substrate

Question 24

What happens if there’s a higher concentration of substrate

Answer 24

then the substrates chances of getting to an active site before the inhibitor increase

So increasing the concentration of substrate will increase the rate of reaction

Question 25

What happens if there’s a higher concentration of substrate

Answer 25

then the substrates chances of getting to an active site before the inhibitor increase

So increasing the concentration of substrate will increase the rate of reaction

Question 26

What are all the steps of a non-competitive inhibitor

Answer 26

1) non competitive inhibitor molecules bind to the enzyme away from its active site
2) this causes the active site to change shape so substrate molecules can no longer bind to it
3) they don’t compete with the substrate molecules to bind to the active site because they are a different shape
4) Increasing the concentration of substrate won’t make any difference to the reaction rate - enzyme activity will still be inhibited