Enzymes 1,2 and 3

Question 1

what happens inside the ATP synthase

Answer 1

the middle and lower parts rotate

Question 2

how does the middle and lower part of ATP synthase rotate

Answer 2

this happens when protons are flowing back into the mitochondria

Question 3

what does the top part of ATP synthase do

Answer 3

merge ATP and phosphate

Question 4

what is a cofactor

Answer 4

a non-protein component that is required to help the enzyme to do its job

Question 5

examples of some cofactors

Answer 5

K+, Mg2+ and Fe2+/Fe3+

Question 6

what are coenzymes

Answer 6

complex organic molecules, usually produced from a vitamin

Question 7

examples of coenzymes

Answer 7

FAD, NAD+ and Coenzyme A

Question 8

what is a prosthetic group

Answer 8

cofactor covalently bound to the enzyme or very tightly associated with the enzyme

Question 9

what is an apoenzyme

Answer 9

the protein component of an enzyme that contains a cofactor

Question 10

what is a holoenzyme

Answer 10

“whole enzyme” - the apoenzyme plus the cofactor(s)

Question 11

what is a substrate

Answer 11

molecule acted on by the enzyme

Question 12

what is an active site

Answer 12

the very point the reaction takes place

Question 13

what are the 6 types of class names for enzymes

Answer 13

oxidoreductases, transferases, hydrolases, lyases, isomerases and ligases

Question 14

what type of reaction does oxidoreductase involve

Answer 14

transfer e-

Question 15

what type of reaction does transferase involve

Answer 15

group transfers

Question 16

what type of reaction does hydrolase involve

Answer 16

hydrolysis (transfer chemical groups to water)

Question 17

what type of reaction does lyases involve

Answer 17

form or add groups to double bonds

Question 19

what is “useful” energy called

Answer 19

Gibs Free Energy (G)

Question 19

what type of reaction does ligase involve

Answer 19

formation of C-C, C-S, C-N or C-O bonds

Question 19

what type of reaction does isomerase involve

Answer 19

transfer groups within molecules (form isomer..)

Question 20

what is the energy barrier

Answer 20

the energy that is require to get to transition sate from ground state (S)

Question 21

a spontaneous reaction must have a (delta)G value of…

Answer 21

negative value (-)

Question 22

what are the 3 ways that enzymes reduce activation energy

Answer 22

entropy, desolvation and induced fit

Question 23

what types of techniques can you use to understand enzyme function

Answer 23

enzyme kinetics, mutagenesis (the ability to change individual amino acids and see how it affects the properties of the enzyme) and 3D structure

Question 24

what happens to initial rate of reaction if there is more substrate

Answer 24

there is a higher initial rate of reaction

Question 25

what can the Vmax tell us

Answer 25

it can tell us how fast a reaction is proceeding when the enzyme is saturated with substrate

Question 26

if there is two or more substrates, how do they react to the enzyme

Answer 26

random order or ordered with a ternary complex, and no ternary complex formation, order/random sequential mechanism, double displacement

Question 27

what is a ternary complex

Answer 27

a protein complex containing three different molecules that are bound together

Question 28

what do allosteric enzymes do

Answer 28

have no reaction speed at the very beginning of the [S]

Question 29

what does vmax indicate

Answer 29

how fast a reaction is proceeding when the enzyme is saturated with substrate

Question 30

what does Km depict

Answer 30

the stability of the enzyme-substrate complex (affinity)

Question 31

what does low and high Km mean

Answer 31

low Km has high substrate affinity and gets to Vmax faster
high Km is the opposite

Question 32

what is the rate limiting factor of the Michealis-Menten equation

Answer 32

the ES–>EP

Question 33

what are catalytic antibodies

Answer 33

antibodies that generated specific to a transition state molecule

Question 34

how does an inhibitor irreversibly bond to an inhibitor

Answer 34

binds to enzyme covalently and thus irreversibly

Question 35

what does the plateau demonstrates in the Michealis-Menten curve

Answer 35

demonstrates zero order kinetics

Question 36

what does the plateau on Michealis-Menten curve indicate

Answer 36

the systems or enzyme is saturated with substrate

Question 37

where is glucokinase found and what is their relation with Km and Vmax

Answer 37

mainly found in the liver and has high Km and Vmax

Question 38

where is hexokinase found and what is their relation with Km and Vmax

Answer 38

is found everywhere and has low Km and Vmax

Question 39

what happens when blood glucose goes up after a meal

Answer 39

glucokinase activity increases

Question 40

describe competitive inhibition binding and how it would appear on a michealis-meten plot

Answer 40

reaches Vmax but increases Km resulting in a right shift compared to normal binding