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Flashcards in Enzymes Deck (50)
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1

Enzyme defintion

Substance that increases rate of reaction but stays same as it was b4

2

Enzyme binds ______ to substrate

Reversibly

3

Enzyme substrate complex ______forms _______

Irreversibly
Product
Regenerates catalyst

4

Active sites contain

Catalytic residues

5

Specifiticty of enzymes involve what forces

Van der Waals
Electrostatic
H-bonding
Hydrophobic interactions

6

Enzyme mechanismm

Facilitates formation of transition state

7

Cofactors

Small molecules bound to enzyme

8

Enzyme with/without cofactor

Without - apoenzyme (inactive)
With - holoenzyme (active)

9

Two groups of cofactors

Metal ions and small organic molecules

10

Coenzymes

Small organic cofactors

11

Prosthetic groups

Coenzymes tightly bound

12

_____ are often precursors to coenzymes

Vitamins

13

V

Number of moles formed per second

14

Km

Concentration of S that is 1/2 of Vmax

15

Km measures

How tightly substrate binds
Lower Km = more tightly bound = more likely to form product

16

V relationship to Vmax and Km

Proportional to Vmax
Inversely proportionalto Km

17

Line-weaver Burke improtant points

X-intercept = 1/-Km
Y-intercept = 1/Vmax
Slope = Km/Vmax

18

Reversible inhibition types

Competitive and noncompetitive

19

Competitve inhibiton

Binds active site
Overcome with more substrate
Changes Km

20

Noncompetitive inhibition

Binds other site
Cannot be overcome with substrate
Changes Vmax

21

Irreversible inhibtion typically

Involves covalently bound
Can bind anywhere

22

Kinase

Transfer of phosphate using ATP

23

Phoshorylase

Adds inorganic phosphate to substrate iwhtout ATP

24

Phosphatase

Removes phosphatre

25

Dehydrogenase

Redox

26

Hydroxylase

Add hydroxyl

27

Carboxylase

Transfers CO2

28

Mutase

Relocates functional group within a molecule

29

Feedbakc inhibition

Product regulates earlier enzyme
Common in metabolism

30

Allosteric and how is it different than noncompetitive

Has allosteric sites that can be activated or inhibited
Sigmoidal M-M kinetics