Which one of the following triplet codes, is correctly matched with its specificity for an amino acid in protein synthesis or as 'start' or 'stop' codon ?

Options

A. UGU - Leucine
B. UAC- Tyrosine
C. UCG- Start
D. UUU - Stop

Explanation

To solve the question regarding the correct matching of triplet codes with their respective amino acids or functions in protein synthesis, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding Codons**: Codons are sequences of three nucleotides in mRNA that correspond to specific amino acids or signals (start/stop) during protein synthesis.

2. **Analyzing Each Option**:
- **Option 1: UGU - Leucine**:
- UGU actually codes for **Cysteine**, not Leucine. Therefore, this option is incorrect.
- **Option 2: UAC - Tyrosine**:
- UAC codes for **Tyrosine**. This option is correct.
- **Option 3: UCG - Start Codon**:
- UCG does not function as a start codon; it codes for **Serine**. The actual start codon is **AUG**, which codes for Methionine. Hence, this option is incorrect.
- **Option 4: UUU - Stop Codon**:
- UUU codes for **Phenylalanine**, not a stop codon. The stop codons are UAA, UAG, and UGA. Thus, this option is also incorrect.

3. **Conclusion**: After analyzing all options, the only correct match is **Option 2: UAC - Tyrosine**.

### Final Answer:
The correct triplet code that is matched with its specificity for an amino acid is **UAC - Tyrosine**.

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