Chymotrypsin - Enzyme Kinetics

Question 1

What type of residues does Chymotrypsin cleave?

Answer 1

aromatic residues, it cleaves their carboxyl groups

Question 2

What is the Michaelis Constant (Km)?

Answer 2

concentration of substrate at which a particular enzyme works at half its maximal velocity

Question 3

What is the rate of reaction denoted by in an enzyme kinetics graph?

Answer 3

V for velocity

Question 4

What does a low Km value indicate?

Answer 4

very tight binding between the substrate and the enzyme (high substrate affinity to enzyme,)
if we are getting half Vmax at a low substrate concentration that means all the substrate is being useful to the enzyme

Question 5

What does a high Km value indicate?

Answer 5

weak binding between the substrate and the enzyme (low affinity), ie more substrate is needed to achieve Vmax

Question 6

What is the reaction’s steady state and when does it happen?

Answer 6

when the enzyme-substrate complex is being formed at the same rate it is being consumed, reaction velocity is constant

the initial rate of reaction (velocity) = steady state

Question 7

What is the lineweaver-burk plot?

Which intercepts can u find the Km & Vo constants?

What is the slope in terms of Km and Vo?

Answer 7

a double reciprocal plot with 1/Vo (1/initial velocity) over 1/[S] (1/substrate conc.)

x-intercept= -1/Km
y-intercept= 1/Vmax

m= Km/Vmax