l Which order of enzymes is correct according to their stren

l. Which order of enzymes is correct according to their strength of binding to the substrate? 0.5 ubstrate cencentrati a) A

Solution

1. Ans: A>B>C.

The Km is the substrate concentration at 1/2Vmax. It is inversely proportional to affinity. Thus lower the Km higher the affinity of enzyme towards the substrate. In this question, the white line intercepting the X axis is Km. The A has lower Km than B, and B in turn has lower Km than C.

2. The protein loses activity in acidic pH. So we can use buffer with pH > 6.5. That will make the protein negatively charged. So we can use anion exchange chromatography.

3. Under non reducing condition, the protein structure is intact , and we got 90kda and. When reducing agent was present, the disulphide bonds are broken and we got 15kda single band. This means the 90kda unit had 15kda smaller units, since 15 x 6 = 90, there are 6 smaller units. Also we got only one band of 15kda,and no other fragment, all the subunits are of same weight. Hence ans is Homohexamer.