Enzyme regulation

Question 1

zymogen forms

Answer 1

inactive enzyme form

Question 2

how are zymogens activated?

Answer 2

peptide bond cleavage

Question 3

thrombin is soluble or non-soluble?

Answer 3

soluble

Question 4

made from prothrombin on a membrane surface

Answer 4

thrombin

Question 5

occurs as a post-trasncriptional modification to prothrombin and its processing enzyme

Answer 5

Gamma Carboxylation

Question 6

what does calcium-dependent binding to a membrane surface requires?

Answer 6

The conversion of some glutamates in prothrombin to gamma-carboxyglutamates

Question 7

thrombin cleaves soluble _______ to yield fibrin monomers forming a ______

Answer 7

Thrombin cleaves soluble fibrinogen to yield fibrin monomers forming a clot

Question 8

vitamin K analogue

Answer 8

warfarin

Question 9

warfarin interferes with

Answer 9

the gamma-carboxylation reaction

Question 10

why is warfarin used?

Answer 10

to reduce over-clotting

Question 11

promotes formation of the thrombin-antithrombin complex

Answer 11

heparin

Question 12

associated with the loss of leastin in the lung due to overactive elastase activity

Answer 12

emphysema

Question 13

change Km but not Vmax

Answer 13

competitive inhibitors

Question 14

_____ increases with increasing amount of competitive inhibitor, because you need more substrate to get ______________

Answer 14

km increases with increasing amount of competitive inhibitor, because you need more substrate to get 1/2 of Vmax

Question 15

change Vmax, but not Km

Answer 15

noncompetitive inhibitors

Question 16

exist in “R” and “T” forms and have binding sites or effectors

Answer 16

allosteric enzymes

Question 17

allosteric enzymes are _______ regulated by _______ concentration and often control a _____ ____

Answer 17

Allosteric enzymes are highly regulated by substrate concentration and often control a reaction pathway

Question 18

a second binding site on the enzyme where the inhibitor binds

Answer 18

feedback inhibition

Question 19

Activity of some serine proteases is _____ by protein inhibitors such as antithrombin for thrombin or alpha-1-antitrypsin

Answer 19

inhibited

Question 20

type of enzyme inhibition where the immediate product of an enzyme reaction binds to the enzyme and inhibits its activity

Answer 20

product inhibition

Question 21

where is prothrombin produced?

Answer 21

by liver cells for export into the blood

Question 22

what happens when prothrombin binds to calcium?

Answer 22

associate with the membrane of different cell types