Finals: ENZYMES

Question 1

-catalyst:

Answer 1

speed up chemical reactions

Question 2

-properties of an enzyme:

Answer 2

peed up chemical reactions, all are globular proteins, all have an active site, can be denatured by heat, substrate specific, can be used over and over, their names end in-ase, function as biological catalysts and increase the rate of a reaction without being consumed by the reaction, speeds up reaction by lowering the energy of activation barrier,

Question 3

-active site:

Answer 3

where substrate binds to enzyme, where reactions occurs, on surface of enzyme, formed by a few of amino acids,

Question 4

-denature:

Answer 4

hen globular proteins unravel, can be denatured by heat,

Question 5

why can’t enzyme work once it is denature

Answer 5

can’t bind substrates, alter specific shape and destroying function (heat), enzyme lose shape, active site changes, can’t bind substrates

Question 6

-substrate specific:

Answer 6

an only bind and create reaction with specific substrate, shape of enzyme determines which chemical reactions the enzyme catalyzes, active sites fit only specific substrate molecules

Question 7

-substrate:

Answer 7

enzyme is involved, reactants = substrates, specific reactions that can enzyme acts on

Question 8

-globular protein:

Answer 8

chain of amino acids folded into a blob

Question 9

-shape

Answer 9

is critical because it determines function (it creates docking spaces)

Question 10

-energy of activation barrier:

Answer 10

energy absorbed to contort or weaken bonds in reactant molecules so that they can break and new bonds can form

Question 11

ES complex:

Answer 11

when substrate is bound, enzyme and substrate complex bond together

Question 12

-when enzymes denature in heat:

Answer 12

temperature affects molecular motion and its optimal temperature produces highest rate of contact between reactant molecules and enzyme’s active site, higher temperature: denatured enzyme and alter specific shape and destroying function, R groups vibrate fast snf denature, interactions start to break and unravel,

Question 13

-when enzymes denature in ph:

Answer 13

outside range of 6-8, enzyme may be impaired,

Question 14

-what factors cause an enzyme to denature:

Answer 14

heat and change in Ph level

Question 15

ompetitive inhibition:

Answer 15

similarly to substrate, competition for active site

Question 16

-inhibition:

Answer 16

eversible when weak interactions bind inhibitor and enzyme, no chemical reactions occur

Question 17

-inhibitors

Answer 17

mimic substrate positions, chemical that interferes with an enzyme’s activity

Question 18

-examples of inhibitors:

Answer 18

poisons, antibiotics (work on bacterial enzymes, not humans), protease (hydrolytic enzyme, reduce proteins to amino acids) caner (chemotherpay ), HIV drugs (protease)

Question 19

non competitive inhibition:

Answer 19

non competitive blocker bonds not on active site, change shape of active site, substrate can’t bind

Question 20

-competitive inhibition

Answer 20

educes enzyme’s productivity by blocking substrates from entering active site, overcome by increasing the concentration of substrate making it more likely that a substrate molecule will be nearby when an active site become vacant

Question 21

-feed back inhibition:

Answer 21

when have enough product, don’t need to make it any more, product act as inhibitor of one of enzymes early in pathway, most important mechanism that regulate metabolism

Question 22

-cofactors:

Answer 22

nonprotein helpers, some are inorganic (ions of zinc, iron or copper

Question 23

-coenzyme:

Answer 23

cofactor is organic molecule, vitamins function as coenzymes

Question 24

indused fit

Answer 24

enzyme slightly changes it shape causing ti to mold around substrate

Question 25

product site

Answer 25

leave enzyme, enzymes can be used again

Question 26

a –> b + C

Answer 26

one substrate, two products