Question

Questions about biochem:

1.) If the ΔG'° of the reaction A --> B is +1000 kJ/mol, under standard conditions the reaction will never reach equilibrium. True or False ?

2.) An enzyme catalyzes the reaction A↔B. The enzyme is present at a concentration of 4 nm, and the Vmax is 1.5 µM s^-1. The Km for substrate A is 10 µM. Which of the following is the initial velocity of the reaction Vo when the substrate concentration is 10 µM?

a. --> 0.25 µM

b. --> 10 µM

c. --> 0.75 µM

d. --> 3 µM

e. --> 1.5 µM

3.) Which of the statements is true regarding FAD cofactor?

I: Comprised of pteridine, p-aminobenzoate, and glutamate

II: Contains N, an adenosine moiety, and a pyrophosphate linkage

III: Transfers 1 or 2 electrons.

IV: Is found in more enzymes than NAD cofactor

A.--> I, IV

B.--> I, II, IV

C. --> II   

D.--> II, III

E.) --> I, II, III, IV

Answer 1

1- The given statement is true. If the  Delta G value is positive then the reaction is not spontaneous. It requires some external energy to carry out in forward direction.

2 - According to the Michaelis-Menten Equation

Vo = Vmax (S)/ Km + (S)

Here Vo is the initial velocity = Need to find out

Vmax is the maximum velocity = 1.5uM/s

Km = 10uM

(S) = 10uM

Vo = 1.5 * 10 / 10+10

= 15/20 = 0.75 uM/s

So Vo = 0.75uM.

So, the correct answer is option c. --> 0.75 µM

3 -

It transfers 1 or 2 electrons.

So correct answer is option  D.--> II, III

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