Lab 5 - Enzyme Kinetics

Question 1

variables

Answer 1

independent: pH
dependent: Km and Vmax

Question 2

enzyme

Answer 2

sorbitol dehydrogenase

Question 3

enzyme’s substrates

Answer 3

sorbitol and NAD

Question 4

product

Answer 4

NADH

Question 5

Km

Answer 5

• -the concentration of substrate that gives half maximal activity
• -calculation: solve for x-intercept, take the inverse, change its sign
• -unit: mmol/L

Question 6

Vmax

Answer 6

• -maximum activity
• -calculation: inverse of y-intercept
• -unit: nmol NADH/ ml min

Question 7

Michaelis-Menten plot showing saturation

Answer 7

the relationship between reaction rate (nmol NADH/ml min) and [sorbitol] (mmol/L)

Question 8

Lineweaver-Burke plot

Answer 8

double reciprocal showing 1/reaction rate (nmol NADH/ml min) and 1/[sorbitol] (mmol/L)

Question 9

non-competitive inhibitor

Answer 9

reduces Vmax

Question 10

competitive inhibitor

Answer 10

raises Km –> higher substrate concentrations are needed to approach Vmax