Reversible Enzyme Inhibition Flashcards Preview

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Flashcards in Reversible Enzyme Inhibition Deck (25):
1

In this type of inhibition, the inhibitor competes with the substrate for the active site of the enzyme

competitive

2

True or false? a competitive inhibitor usually has some structural similarity to the substrate

true

3

What does a competitive inhibitor bind to?

free enzyme

4

Competitive inhibition increases the "apparent" ___ of the enzyme

Km

5

The following describes what type of inhibition? By removing some of the free enzyme from the reaction, it appears to take a higher [S] to achieve 1/2 Vmax

competitive

6

What does competitive inhibition look like on lineweaver - burk plot?

X intercept is different but lines go through Y intercept at same point

7

In competitive inhibition, Vmax is unaffected. Explain why.

since by increasing [S], the inhibition can be overcome and Vmax can be achieved

8

___ are competitive inhibitors of the rate limiting enzyme of cholesterol biosynthesis

statins

9

The following version of the michaelis-menten equation describes what type of inhibition:

v = Vm[S] / Km(1+[I]/Ki)+[S]

competitive

note: only Vm[S] is on top

10

A noncompetitive inhibitor binds to either ___ or ___

E; ES

11

Do noncompetitive inhibitors bind to the active site?

no, therefore don't compete with substrate binding

12

Since a noncompetitive inhibitor doesn't compete with the S, increasing [S] will have what effect?

none, won't overcome the inhibition

13

A noncompetitive inhibitor decreases the "apparent" ___ of the enzyme

Vmax

14

The effect of a ____ inhibitor is to effectively reduce the number of active enzyme molecules, which has the appearance of reducing [Etotal]

noncompetitive

15

What does noncompetitive inhibition look like on a lineweaver-burk plot?

X intercepts are the same but lines cross at different points on Y intercept

16

The following version of the michaelis-menten equation describes what type of inhibition:

v = Vm[S]/(1+[I]/Ki)//Km+[S]

noncompetitive

note: only Km + [S] on bottom

17

Many heavy metals such as Hg and Pb interact with the -SH groups on enzymes and act via ____ inhibition

noncompetitive

18

An uncompetitive inhibitor binds only to the ___ of an enzyme

ES

19

In uncompetitive inhibition, it is proposed that substrate binding alters the enzyme structure such that...

the inhibitor may subsequently bind

20

The inhibitor does not compete with the substrate for the active site in uncompetitive inhibition. True or false?

true

21

In uncompetitive inhibition, as [S] increases, so does inhibition since ES is required for the inhibitor, there for Vmax is ____

decreased

22

What does uncompetitive inhibition look like on a line-weaver burk plot?

parallel lines

23

In the presence of an uncompetitive inhibitor, there will be an apparent Vmax ___ than the true Vmax and an apparent Km ___ than the true Km

less; less

24

The following version of the michaelis-menten equation describes what type of inhibition:

v = Vm[S]/1+[I]/Ki//Km/1+[I}/Ki + [S}

uncompetitive

note: a whole lot going on up top and on bottom

25

____ inhibitors are rare in single substrate enzymes but more common in multi-substrate enzymes

uncompetitive