An analysis of the hydrolysis products of salmine, a polypeptide from salmon gave following result of weights of amino acidsd in gram per 109.66g of salmine
`{:(Ie :,"Isoleusine : 1.31","Alanine : 0.89","Serine : 7.35","Argemine : 86.40"),(,"valine : 3.51","Glycine : 3.0","Proline : 6.90",):}`
`{:("molecular weight of salmine is : 10, 966","molecular weight of Serine : 105"),("molecular weight of alanine is : 89","molecular weight of Argenine : 174"),("molecular weight of Isoleucine : 131","molecular weight of Protine : 115"),("molecular weight of Valine : 117","molecular weight of Glycine : 75"):}`
Singly present amino acids in the salmine are

Options

A. Serine & valine
B. Isoleucine & proline
C. Alanine & Glycine
D. Alanine & Isoleucine

Explanation

To determine the singly present amino acids in salmine, we need to analyze the given data regarding the weights of amino acids obtained from the hydrolysis of salmine. Here’s a step-by-step solution:

### Step 1: List the Amino Acids and Their Weights
We have the following amino acids and their respective weights (in grams per 109.66 g of salmine):

- Isoleucine: 1.31 g
- Alanine: 0.89 g
- Serine: 7.35 g
- Arginine: 86.40 g
- Valine: 3.51 g
- Glycine: 3.0 g
- Proline: 6.90 g

### Step 2: Identify the Molecular Weights of Each Amino Acid
The molecular weights of the amino acids are provided as follows:

- Molecular weight of Serine: 105 g/mol
- Molecular weight of Alanine: 89 g/mol
- Molecular weight of Arginine: 174 g/mol
- Molecular weight of Isoleucine: 131 g/mol
- Molecular weight of Proline: 115 g/mol
- Molecular weight of Valine: 117 g/mol
- Molecular weight of Glycine: 75 g/mol

### Step 3: Determine the Presence of Each Amino Acid
To find out which amino acids are singly present, we need to check the weights of each amino acid. A singly present amino acid would typically have a weight that indicates it appears only once in the polypeptide chain.

### Step 4: Analyze the Weights
From the given weights:
- Isoleucine: 1.31 g
- Alanine: 0.89 g
- Serine: 7.35 g (appears multiple times)
- Arginine: 86.40 g (appears multiple times)
- Valine: 3.51 g (appears multiple times)
- Glycine: 3.0 g (appears multiple times)
- Proline: 6.90 g (appears multiple times)

### Step 5: Identify the Singly Present Amino Acids
From the analysis, we can see that:
- Isoleucine and Alanine are the only amino acids that have lower weights compared to others, suggesting they are present singly.

### Conclusion
The singly present amino acids in salmine are:
- **Isoleucine**
- **Alanine**