Enzyme action 2.1.4 (a,b,c)

Question 1

what are enzymes?

Answer 1

biological catalysts

Question 2

what are the properties of enzymes?

Answer 2

globular proteins with a specific 3D shape

Question 3

what do enzymes do?

Answer 3

lower the activation energy needed for a substrate to react

allows substrates to react at a faster rate

Question 4

what are anabolic reactions?

Answer 4

reactions which are required for growth

catalysed by enzymes

Question 5

what are catabolic reactions?

Answer 5

reactions which are required for breaking down

catalysed by enzymes

Question 6

what effects enzyme activity?

Answer 6

temperature
pH
pressure

Question 7

what is the Vmax?

Answer 7

the maximum rate of an enzyme-controlled reaction

Question 8

how does a reaction work?

Answer 8

molecules collide with each other at the right energy level for it to be a successful collision

Question 9

what is the activation energy?

Answer 9

the energy required for a reaction to start

Question 10

why do enzymes lower the activation energy?

Answer 10

they bind to reacting molecules to help them collide successfully

Question 11

what are the two hypotheses for enzyme action?

Answer 11

lock and key hypothesis
induced-fit hypothesis

Question 12

outline the lock and key hypothesis

Answer 12

the tertiary structure of an enzyme produces a shape which is complimentary to a specific substrate molecule - called the active site

the specific substrate binds to the active site to form an enzyme-substrate complex

the substrates then react and the products formed form an enzyme-product complex

the products leave and the enzyme is able to take another substrate

Question 13

what is the active site?

Answer 13

area of a protein which has a shape similar to the substrate

Question 14

outline the induced-fit hypothesis

Answer 14

the active site of an enzyme changes shape when it interacts with a substrate

the interactions lead to a change in the enzyme’s tertiary structure which increases the binding and puts further strain on the substrate

this leads to the bonds being weakened and thus lowering the activation energy

Question 15

what are the two types of enzyme?

Answer 15

intracellular
extracellular

Question 16

what are intracellular enzymes?

Answer 16

enzymes which work within a cell

Question 17

example of intracellular enzymes?

Answer 17

catalase

Question 18

what does catalase do?

Answer 18

breaks down hydrogen peroxide into oxygen and water

prevents it’s toxic accumulation

Question 19

what are extracellular enzymes?

Answer 19

enzymes which work outside of a cell

Question 20

why are extracellular enzymes important?

Answer 20

large polymers need to be broken down into smaller groups before they can enter a cell

Question 21

examples of extracellular enzymes?

Answer 21

amylase
trypsin

both used in digestion

Question 22

what is trypsin?

Answer 22

it is a protease which breaks down proteins into smaller peptides which are later broken down into amino acid

Question 23

where is trypsin released from?

Answer 23

the pancreas

Question 24

how is starch digested?

Answer 24

amylase breaks starch into maltose

maltase breaks maltose into glucose which is then absorbed into the blood stream