A purified pepsin was subjected to amino acid analysis. The amino acid present in smallest amount was lysine, `C_(6)H_(14)N_(2)O_(2)` and the amount of lysine was found to be 0.43 g per 100 g of protein. The minimum molecular mass of protein is

Options

A. `3400 u`
B. `34,000 u`
C. `340,000 u`
D. `340 u`

Answer

B

Explanation

Molecular mass of lysine `C_(6)H_(14)N_(2)O_(2)=146 u`
Mass of lysine (minor component) per gram of macromolecule `=(0.43)/(100)=0.0043g`
Minimum molecular mass
`=("Molecular mass of lysine")/("Mass of lysine per gram of macromolecule")`
`=(146u)/(0.0043)=34,000`