If the molecular mass of an amino acid is 150 daltons, the molecular mass of a tripeptide will be

Options

A. 414
B. 486
C. 504
D. 450

Answer

To find the molecular mass of a tripeptide formed from amino acids, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Molecular Mass of One Amino Acid:**
- Given that the molecular mass of one amino acid is 150 daltons.

2. **Calculate the Total Molecular Mass of Three Amino Acids:**
- Since a tripeptide consists of three amino acids, we can calculate the total mass of these three amino acids:
\[ \text{Total mass of 3 amino acids} = 3 \times 150 \text{ daltons} = 450 \text{ daltons} \]

3. **Account for Water Molecules Released:**
- When forming a peptide bond, a molecule of water (H₂O) is released. In the formation of a tripeptide, two peptide bonds are formed (one between each pair of amino acids), resulting in the release of two water molecules.
- The molecular mass of one water molecule is approximately 18 daltons. Therefore, the total mass of the two water molecules released is:
\[ \text{Mass of 2 H₂O} = 2 \times 18 \text{ daltons} = 36 \text{ daltons} \]

4. **Calculate the Molecular Mass of the Tripeptide:**
- To find the molecular mass of the tripeptide, we subtract the mass of the water molecules released from the total mass of the three amino acids:
\[ \text{Molecular mass of tripeptide} = \text{Total mass of 3 amino acids} - \text{Mass of 2 H₂O} \]
\[ \text{Molecular mass of tripeptide} = 450 \text{ daltons} - 36 \text{ daltons} = 414 \text{ daltons} \]

5. **Final Answer:**
- The molecular mass of the tripeptide is **414 daltons**.