6. Enzymes and Enzyme Kinetics

An enzyme catalyzes a reaction at a velocity of 10 μmol/min when all enzyme active sites are occupied with substrate. The K_m for this substrate is 1 x 10^-5 M. Assume that Michaelis-Menten kinetics are followed, calculate the initial reaction velocity (V₀) when:

A) [S] = 1 x 10^-5 M. V₀ = ___________ 

B) [S] = 1 x 10^-2 M. V₀ = ___________

A) Suppose the [S] = 10 K_m. Use the Michaelis-Menten equation to determine what percentage of the V_max will be equal to the value of V ₀.

B) Now suppose the [S] = 20 K_m. Use the Michaelis-Menten equation to determine what percentage of the V_max will be equal to the value of V ₀. What conclusion can be made from these calculations?

Which of the following statements about a V₀ vs. [S] plot for a Michaelis-Menten enzyme is false?

What is the ratio of [S] to K_m ( [S] / K_m ) when the V₀ of an enzyme-catalyzed reaction is 80% of the V_max?

An enzyme-catalyzed reaction was carried out with a [substrate] initially 1000 times greater than the Km for that enzyme. After 9 minutes, 1% of the total substrate was converted into 12 μmoles of product. If in a separate experiment, one-third as much enzyme and twice as much substrate had been combined, how long would it take for the same amount of product (12 μmoles) to be formed?