Enzyme Kinetics

Step 1: Understanding equilibrium constant.
At equilibrium, the concentration of products and reactants is related by the equilibrium constant . The reaction is: Let the initial concentration of Glu-6-P be . At equilibrium, the concentration of Glu-6-P is , and the concentration of Fru-6-P is . The equilibrium constant is given by: Step 2: Conclusion.
The equilibrium constant is 20.

Step 1: Understanding enzyme kinetics.
The Michaelis-Menten constant and the catalytic rate constant are intrinsic properties of the enzyme and do not change with enzyme concentration. However, , which represents the maximum reaction velocity, is directly proportional to enzyme concentration.
Step 2: Analyzing the options.
(A) : Incorrect — is independent of enzyme concentration.
(B) : Correct — increases when enzyme concentration is doubled.
(C) : Incorrect — is a constant that does not change with enzyme concentration.
(D) : Incorrect — is related to the equilibrium constant and does not depend on enzyme concentration.
Step 3: Conclusion.
The correct answer is (B) , as doubling the enzyme concentration increases .

Step 1: Understanding the first-order reaction equation.
For a first-order reaction, the amount of substrate remaining after time is given by: where is the concentration at time , is the initial concentration, and is the rate constant.

Step 2: Using the information given.
Given that 80% of the substrate is converted in 10 minutes, 20% remains, so: Substitute into the equation:

Step 3: Solving for .
Taking the natural logarithm of both sides: Using :

Step 4: Conclusion.
The rate constant is .