Question

A scientist took 8 molecules of cytosoic aldolase into an enzyme reaction mixture to study its activity. After ten minutes of enzyme reaction, 60% of its substrate was found converted into 2400 molecules of products. Then what is the TON of aldolase and number of substrate molecules left over in the reaction mixture?

• A. $30,1440$
• B. $30,960$
• C. $15,1280$
• D. $15,800$

Answer 1

Answer: (D)

$15,800$

Turnover Number = number of molecules of substrate converted to product per time by one active site.

Fructose 1,6-bisphosphate is converted by the enzyme aldolase into the triose phosphates- dihydroxyacetone phosphate and glyceraldehyde 3-phosphate.

If the total number of products after 10 minutes is 2400, the number of converted substrates is 2400/2 = 1200.

Hence turnover number = 1200/10 x 8= 15.

Here, total number of substrate = 1200 x 100/60 = 2000

So, the remaining substrate molecule is 2000-1200 = 800

Thus the correct answer is option D.