2.5

Question 1

what is the active site

Answer 1

the special area on the enzyme were the actual catalytic reaction takes place

Question 2

what is the interaction between the substrate and active site like

Answer 2

very specific

only one type of substrate fits into the active site

enzyme-substrate specificity

Question 3

what is the active site a result of

Answer 3

the folding of the polypeptide chain, resulting in a 3d shape formed b the polypeptide chain frost the active site where the substrate interacts with the enzyme.

Question 4

what happens when the substrate enters the enzymes active site

Answer 4

the enzyme changes shape slightly, induced fit results in tighter binding of the substrate to the active site

Question 5

what are enzymes

Answer 5

biological catalyst, globular proteins that can speed up a biochemical reaction

Question 6

what is the induced fit model

Answer 6

suggests that when the substrate enters the active site, it triggers a change in the three dimensional shape of the enzyme that allows a tighter fit, called an induced fit. this is possible because of the flexibility of the protein molecules that make up thhe enzyme

when they fit together tightly, the enzyme induces the weakening of bonds within the molecules of the substrate, thus reducing the activation energy needed for the reaction.

Question 7

what theory did the induced fit model replace

Answer 7

the lock and key theory

Question 8

what did the lock and key hypothesis

Answer 8

enzyme functions as a lock while the substrate functions as a key, there is a perfect match

the induced fit model suggests that a substrate is capable of inducing a change

Question 9

there are three steps of the induced fit model

Answer 9

attraction - substrate enters the enzyme

reaction - substrate enzyme complex, conformational change

release - products of the reaction are released, enzyme reverts to original shape

Question 10

what is the active site

Answer 10

the sequence of amino acids responsible for the catalytic activity of enzymes

Question 11

what is activation energy

Answer 11

the minimum energy required that reacting particles should possess in order for a reaction to occur

Question 12

how do enzymes affect the activation energy

Answer 12

the activation energy is lowered

Question 13

what is a catalytic reaction

Answer 13

when an enzyme converts the substance into products such as when amylase hydrolyses starch to produce di and monosaccharides

Question 14

what does enzyme catalysis involve

Answer 14

molecular motion and collision of substrates

Question 15

what is an exothermic or exergonic reaction

Answer 15

a reaction where product formation is associated with release of energy

Question 16

what is an endothermic/endergonic reaction

Answer 16

a reaction where product formation is associated with absorption of energy

Question 17

what factors can affect the catalytic properties of enzymes

Answer 17

temperature, pH, substrate concentration and enzyme concentration

Question 18

how does temperature affect enzymes

Answer 18

low - enzymes move slowly, low chance of collision

optimum temp - rate of enzymatic reaction is the highest

too high - enzyme can denature

graph - slow increase, peak, rapid decrease straight line down

Question 19

how does substrate concentration affect enzymes

Answer 19

low - more enzymes than substrate, rate of reaction is low

increasing - more substrates, more chances of collision, enzymatic reaction rises gradually

increase is halted when all active sites are occupied by substrate molecules after this point, adding more substrate does not affect the rate of reaction.Vmax

Question 20

how does pH affect enzymes

Answer 20

enzymes have their own optimum pH which differs, extreme values can denature an enzyme by altering the three dimensional structure of its active site however, if the pH is just a little lower of higher than the optimal, the rate of reaction gradually decreases

Question 21

when is denaturing irreversible

Answer 21

in extreme conditions, such as in eggs, usually it is reversible

Question 22

what does denaturation do to an enzyme

Answer 22

it destroys the tertiary or quaternary conformation of a protein. when the temperature is high enough or the pH is extreme, the secondary structure of a protein can be altered

Question 23

what happens If the change in temperature and pH is only minor

Answer 23

some proteins may still be reversible

Question 24

different uses of industrial enzymes

Answer 24

industry

environment
agriculture

Question 25

uses of enzymes in the industry

Answer 25

protein hydrolysis 
detergent 
food processing 
chemical 
leather tanning 
biofuel

Question 26

uses of enzymes in the environment

Answer 26

degradation of residual wate

detoxification of toxic substace

Question 27

use of enzymes in agriculture

Answer 27

feed proccessing
animal feed additive
agroprocessinf

Question 28

what does milk consist of

Answer 28

lactose which is made up of glucose and galactose

Question 29

what is lactase

Answer 29

an enzyme that breaks down lactose into glucose and galactose

Question 30

advantages of lactose free milk

Answer 30

sweeter tasting
no ill effects after consumption

quicker fermentation

Question 31

how is lactose free milk made

Answer 31

by adding the enzyme lactase to milk which breaks it down into glucose and galactose.

alternatively, lactase can be immobilized in alginate beads while the milk is allowed to flow past.

Question 32

how can you investigate catalase

Answer 32

substrate - hydrogen peroxide

product - oxygen

Question 33

how can you investigate lipase

Answer 33

substrate - lipids

product - fatty acids

Question 34

how can you investigate pepsin

Answer 34

substrate - protein

product - amino acid and short peptides

Question 35

how can you investigate amylase

Answer 35

substrate - starch

product - maltose