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Flashcards in Enzymes II Deck (28):
1

what is general acid base catalysis

ionizale R groups of active site serve as proteon donors and acceptors during reaction

2

What is formation of covalent intermediates

transient formation of a covalent bond between the substreate and active site R groups

3

how do metal ions paticipate in catalysis

postive charge stabilizes negatively charged intermediates
generates a nucleophile
bind to substrate

4

examples of metaloenzymes

carbonic anhydrase

5

what does carbonic anyhydrase contain

active site Zn2+ ion

6

how does carbonic anhydrase act as a catalyze

Zn2+ binds to water and reduces pKa
faciliate OH- ion formation at physiologcial pH
CO2 binds active site
OH- attacks CO2 forming bicarb

7

how does temperature affect reaction

rxn speeds up as temp incrases but at a certain point it denatures the enzyme

8

v

rate of enzyme catalyzed reaction

9

international units (U)

amoun tof enzyme required to convert 1 Mmol of substrate into product in 1 min at saturating substreate conc

10

katal (kat)

amount of enzyme required to convert 1 mol of substrate into product in one second

11

turnover number

the number of catalytic cycles that one enzyme molecule can perform in one second

12

michaelis-menten graph

measures rate of product formation by a fixed amount of enzyme at diff. concentrations of substrate

13

low Km indicates what

tight binding of substrate

14

high Km indicates what

weaker binding of substrate

15

what is late onset hyperammonemia caused by

mutations in OTCase

16

what is the mutation in OTCase

R277W, replace of arginine with glutamine

17

slope in lineweaver burk plot

Km/Vmax

18

y in lineweaker burk plot

1/max

19

when is x=1 in lineweaver burk plot

-1/Km

20

reversible inhibitor

removal of inhibitor fully resotres enzyme actiity

21

irreversible inhibotrs

remobal of inhinotr does not restore enzyme activity

22

what is the most common type of reversible inhibotr

competivte

23

how does competitive inhibor affect Km and Vmax

increases Km
doesn't affect Vmax

24

non-competitive inhibotr

bind at sites other than active site

25

how does non-competitive inhibotr affect Vmax and Km

decrase Vmax
does not affect Km

26

what are examples of competitive inhibotrs

acetaminophen, ibuprofen

27

most drugs are waht

competitive inhbitors

28

why would non-competitive inhibotors theortically make better drugs

they can inhibit enzyme acitive irrespective of substrate conc