Enzyme Kinetics Flashcards Preview

MCAT biochemistry > Enzyme Kinetics > Flashcards

Flashcards in Enzyme Kinetics Deck (16):
1

enzyme kinetics is the study of

the rate of formation of products from substrates in the presence of an enzyme

2

the reaction rate value is equal to

V = velocity
amount of product formed per unit time, in moles per seconds (mol/s), which depends on the concentration of substrate and enzyme

3

does the substrate or enzyme concentration fluctuate more in a reaction?

substrate concentration does

4

the reaction rate, V, is directly proportional to the substrate added when...

there is little substrate originally present
when there is so much substrate the active sites of enzyme are occupied thus addition of substrate does not affect the reaction rate

5

the term saturated refers to

when there’s so much substrate that every active site is continuously occupied and adding more doesn’t effect reaction rate and this is denoted as Vmax

6

michaelis constant (Km) indicates the substrate concentration when

the reaction rate is 1/2 of Vmax

7

a low Km of an enzyme-substrate means that

not very much substrate is require to get the reaction rate to half the maximum rate
thus enzyme has a high affinity for particular substrate
vice versa with high Km

8

cooperativity is a type of substrate binding to

multiple active site enzymes, in which the binding of one substrate molecule changes the binding of subsequent substrate molecule

9

when the binding of a substrate to one subunit increases the affinity of the other subunits of the substrate, this is

positive cooperativity

10

when the binding of a substrate to one subunit reduces the affinity of the other subunits for substrate, this is

negative cooperativity

11

zero order reaction rate means

there is not effect

12

first order reaction rate means

the concentration is double and the rate is doubled

13

second order reaction rate means

the concentration is double and the rate is quadrupled

14

rate law expression is

rate = k[A]'[B]'

15

in an enzyme-catalyzed reaction, the substate is

a reactant

16

line-weaver burk plot is a

double reciprocal plot that can determine Vmax and Km