Mr P bio 3 Emzymes

Question 1

what type of covalent bond is found in proteins?

Answer 1

peptide

Question 2

what elements are found in all proteins?

Answer 2

Carbon, Hydrogen, Oxygen and Nitrogen

Question 3

what are the two types of protein?

Answer 3

fibrous and globular

Question 4

what are fibrous proteins?

Answer 4

typically long and thin, insoluble and often structural functions e.g. Keratin

Question 5

what are globular proteins?

Answer 5

more spherical in shape, soluble, often biochemical functions e.g. Enzymes

Question 6

how do enzymes increase the rate of reaction?

Answer 6

by lowering the activation energy

Question 7

what are the stages of the induced fit model?

Answer 7

The substrate isn’t complementary, the substrate binds to the active site to form a enzyme-substrate complex and induces a change in the active site to make it complementary, the enzyme puts pressure on the bond of the substrate which reduces the activation energy of the reaction.

Question 8

what is the effect of temperature on rate of reaction (enzymes)?

Answer 8

as temp increases, initially, rate of reaction increases due to an increase in kinetic energy resulting in more successful collisions and enzyme-substrate complexes formed. then the rate of reaction reaches a peak at the optimum temperature before the enzyme begins to denature and can no longer form enzyme-substrate complexes and the rate of reaction rapidly decreases to zero

Question 9

which type of bond is unaffected by temperature?

Answer 9

disulphide bridges

Question 10

what does changing the pH alter the amount of?

Answer 10

H+ or OH- ions

Question 11

what happens if the change of pH is small?

Answer 11

main effect= alters the charges on amino acids that make up he active site of enzymes so the substrate can no longer bind

Question 12

what happens if the change in pH is large?

Answer 12

breaks down hydrogen and ionic bonds that maintain the active site + structure of enzyme so the enzyme is denatured

Question 13

what is the effect of pH on (enzymes) rate of reaction?

Answer 13

if the pH is at too high or low then the charges on the amino acids will be altered which breaks the ionic bonds between the R groups so the tertiary structure is changed and the shape of active site is no longer complementary to the substrate so no enzyme-substrate complexes are formed

Question 14

what is the effect of substrate concentration on (enzymes) rate of reaction?

Answer 14

as substrate concentration increases the rate of reaction also increases as more enzyme substrate complexes are formed due to more successful collisions, however when it reaches a certain concentration the enzymes become the limiting factor as there are not enough to bind to the substrate so it doesn’t have an affect on the rate of reaction.

Question 15

what are the two types of inhibitors?

Answer 15

competitive and non-competitive

Question 16

what bonds are formed in the secondary structure of proteins?

Answer 16

hydrogen bonds

Question 17

name two globular proteins

Answer 17

haemoglobin and enzymes

Question 18

what is the bond in a triglyceride?

Answer 18

ester

Question 19

what do competitive inhibitors do?

Answer 19

they are a similar shape to the substrate so binds to the active site and therefore prevents enzyme-substrate complexes from forming, this decreases the rate of reaction temporarily

Question 20

what do non-competitive inhibitors do?

Answer 20

binds to the allosteric site and changes the tertiary structure so the active site and substrate are not complementary, this is often permanent/ irreversible

Question 21

what is a competitive inhibitors affect on the rate of reaction?

Answer 21

as substrate concentration increases the rate of reaction increases but at a slower rate however ultimately reaches the same final rate of reaction as a reaction without a competitive inhibitor

Question 22

what is a non-competitive inhibitors affect on the rate of reaction?

Answer 22

as substrate concentration increases the rate of reaction increases but at a slower rate however ultimately reaches a lower final rate of reaction as a reaction without a un-competitive inhibitor

Question 23

what is the advantages of using an immobilized enzyme? (3)

Answer 23

can be reused, is a continuous process, and the temperature speed and pH is kept consistent (enzyme kept stable)