Question

Which of the following is/are true regarding initial and maximal velocity of enzyme-mediated reactions?

Answer 1

Answer:

a. True

b. True

c. False

d. True

Explanation:

a). A a very low substrate concentration , $S$. Thus according to the Machaelis-Menten equation becomes

$V_0 = \frac{V_{max} \times [S]}{Km}$

Here since the $V_0$ varies directly to the substrate concentration [S], the initial velocity is lower than the maximal velocity. Thus option  (a) is true.

b). The Michaelis -Menten kinetics equation states that :

   $V_0 = \frac{V_{max} \times [S]}{Km+[S]}$

  Here the initial velocity changes directly with the substrate concentration as $V_0$ is directly proportional to [S]. But $V_{max}$ is same for any particular concentration of the enzymes. Thus, option (b) is true.

c). As the substrate concentration increases, the initial velocity also increases. Thus option (c) is false.

d). Option (d) explains the procedures to estimate the initial velocity which is correct. Thus, option (d) is true.