If in m-RNA, base sequence is 5' - AUG CUA UAC CUC CUU UAU CUG UGA-3'. How many amino acid residues will make up the polypeptide corresponding to this m-RNA

Options

A. Ten
B. Seven
C. Eight
D. Eleven

Answer

To determine how many amino acid residues will make up the polypeptide corresponding to the given mRNA sequence, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the mRNA Sequence**:
The given mRNA sequence is:
\[ 5' - AUG CUA UAC CUC CUU UAU CUG UGA - 3' \]

2. **Divide the Sequence into Codons**:
mRNA is read in sets of three nucleotides called codons. We will break the sequence into codons:
- AUG
- CUA
- UAC
- CUC
- CUU
- UAU
- CUG
- UGA

3. **Count the Codons**:
We count the number of codons formed:
- Total codons = 8

4. **Identify the Amino Acids Corresponding to Each Codon**:
- AUG → Methionine (Met)
- CUA → Leucine (Leu)
- UAC → Tyrosine (Tyr)
- CUC → Leucine (Leu)
- CUU → Leucine (Leu)
- UAU → Tyrosine (Tyr)
- CUG → Leucine (Leu)
- UGA → Stop codon (termination)

5. **Determine the Number of Amino Acids**:
The UGA codon is a stop codon, which means it does not code for an amino acid. Therefore, we will not count it in the total number of amino acids.

Thus, the total number of amino acids coded by the sequence is:
- Total amino acids = 8 codons - 1 stop codon = 7 amino acids

### Final Answer:
The polypeptide corresponding to the given mRNA sequence will be made up of **7 amino acid residues**.

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