Question

A student has taken 6000 molecules of fructose 1, 6-bisphosphate and 2 molecules of aldolase into an enzyme reaction mixture to determine its activity. After 5 minutes, 50% substrate was found converted into products. Then, what is the TON of aldolase and the total number of trioses formed by the enzyme action at the end of 5 minutes?

• A. 300, 3000
• B. 300, 6000
• C. 600, 3000
• D. 30, 6000

Answer 1

Answer: (B)

300, 6000

Turnover number is equivalent to the number of substrate molecules converted to product in a given unit of time on a single enzyme molecule, when a enzyme is saturated by substrate. Aldolase converted one substrate molecule to one product molecule.
If the total number of product after 5 minutes is (3000*2) = 6000.
So, the TON = 3000/(5*2) = 300
The total number of trioses formed by the enzyme action at the end of 5 minutes is 6000 (as one aldolase converts fructose bis phosphate into 2 triose phosphate).