Enzymes

Question 1

1.7 Enzyme action
catalysts lower activation energy

Answer 1

sucrose+water—>glucose+fructose
S + W must collide with enough energy to alter the arrangement of atoms
free energy of products must be lower than that of substrate
catalyst reduce the minimum energy to activate the reaction
Allow reactions to occur at the low energy of the body

Question 2

Enzyme structure

Answer 2

a specific region of the enzyme-active site
-small depression within the larger enzyme
molecule on which the enzyme acts on-substrate
-form the enzyme-substrate complex
substrate attaches to enzyme through temporary bonds

Question 3

Induced fit of enzyme

Answer 3

Active site forms as the E and S interact
change in the environment of the leads to a change in the enzyme
enzyme is flexible. So moulds to the substrate shape
enzyme has a general shape but only gets the specific shape after substrate

Question 4

1.8 Factors affecting enzyme action

Answer 4

*PH
*Temperature

Question 5

Measuring enzyme-catalysed reactions (changes from catalysts)

Answer 5

changes from catalysts
-formation of the products of oxygen
-disapearence of a substrate

Question 6

explanations for enzyme activity

Answer 6

-lot of substrate and no product
-easy for substrate to come into contact with enzymes
-all active sites are filled at any given moment
-amount of substrate decreases and product is increased
-less substrate for active site filling
and products get in the way of filling active site
-longer for substrate to break and products to form. so production of production and the disappearences of substrate tail off.
-graph flatten off bcz all substrate are used up so no new products are formed

Question 7

measuring rate of change

Answer 7

tangent at point needed to measure rate of change
gradient y2-y2/x2-x1

Question 8

Effect of temperature on enzyme action

Answer 8

-rise in temp increases the kinetic energy
∴ increase in collisions between S&E
-moe effective collisions
-in a graph it shows a rising curve
-however, high temp causes the H and other bonds to break
∴ causes the proteins to change shape
hence,substrate fits less easilly
so the slope decreases
after higher temp enzyme stop working altogethor

Question 9

Denaturing

Answer 9

permanent change of enzyme shape

Question 10

Effect of PH on enzyme action

Answer 10

each enzyme has a optimum PH
PH affects in-alters charges on the active site.S can no longer be attached to A.S
could cause the bond that creats the tertiary structure to break

Question 11

Effect of enzyme concentration on the rate of reaction

Answer 11

if excess of S, increase of E will cause a increase in products
if there is a limitng number of S, INCREASE in E will not change rate of reactions as nothing is in the AS of the new enzymes

Question 12

Effects of substrate concentration on the rate of enzyme action

Answer 12

rate of reaction will increase in proportion to the concentration of the S

Question 13

1.9 Enzyme inhibition
types

Answer 13

Directly or indirectly interfere with the functioning of the active site.
∴ reduce its activity
two types
1. Competitive-bind to active site
2.Non-competitive- bind to enzyme at a position other than the active site

Question 14

Competitive Inhibitors

Answer 14

Have molecular shape similar to the specific substrate
∴ compete with the substrate for the
available active site
conc of I to conc of S determines the effectiveness
not permanently bound. another molecule takes it place after
eg; succinate (S). malnate(I)
transpeptidase (E) penicillin(I)

Question 15

Non-competitive inhibitors

Answer 15

Attach to enzyme in places other than the AS
Upon attaching the (I)alters the shape of E
∴ changer the AS.substrate cant attach