Chapter 23, Problem 51A

Interpretation Introduction

Interpretation:

The number of amino acids present in protein should be calculated having molecular mass of 36, 500 g/mole.

Concept introduction:

Proteins are polymeric biomolecules which are formed by the polymerisation of amino acids. Amino acids are the organic molecules with $–{\text{NH}}_{\text{2}}$ and −COOH functional groups bonded on same carbon atom of the molecule.

They polymerise by peptide linkage to form dipeptide, oligopeptide and polypeptide molecules. Each peptide bond formation is a condensation reaction that occurs with the elimination of water molecule.

Number of amino acids is calculated as:

$\text{Number of amino acids}=\frac{\text{Molecular mass of an amino acid}}{\text{Total molecular mass}}$

Answer to Problem 51A

Number of amino acids $\simeq 332$

Explanation of Solution

The average molecular mass of an amino acid = 110 g/mole

Molecular mass of an amino acid = 36, 500 g/mole

The mathematical expression is:

$\text{Number of amino acids}=\frac{\text{Molecular mass of an amino acid}}{\text{Total molecular mass}}$

Put the values,

$\text{Number of amino acids}=\frac{\text{36, 500 g/mole}}{\text{110 g/mole}}$

= $331.81$

Number of amino acids $\simeq 332$