The first translated codon in any mRNA binds to an anticodon is

Options

A. 3. UAC 5.
B. 5. UAC 3.
C. 3. UAU 5.
D. 5. CAU 3.

Answer

To solve the question regarding the first translated codon in any mRNA that binds to an anticodon, we can follow these steps:

### Step-by-Step Solution:

1. **Identify the Start Codon**:
The first codon in mRNA that is translated is known as the start codon. The universal start codon is AUG, which codes for the amino acid Methionine.

2. **Understand Codon-Anticodon Pairing**:
Codons are sequences of three nucleotides in mRNA that correspond to specific amino acids. Anticodons are complementary sequences found on tRNA that pair with the codons during translation.

3. **Determine the Directionality**:
mRNA is read in the 5' to 3' direction. Therefore, the start codon AUG will also be oriented in this direction. The corresponding anticodon will be complementary and oriented in the 3' to 5' direction.

4. **Find the Anticodon for AUG**:
The anticodon that pairs with the start codon AUG can be determined by finding the complementary bases:
- A (Adenine) pairs with U (Uracil)
- U (Uracil) pairs with A (Adenine)
- G (Guanine) pairs with C (Cytosine)

Therefore, the anticodon for AUG is UAC.

5. **Consider the Orientation of the Anticodon**:
Since the anticodon is complementary to the codon, it will be written in the 3' to 5' direction. Thus, the anticodon UAC will be oriented as 3'-UAC-5'.

6. **Select the Correct Option**:
Among the provided options, we need to choose the one that correctly represents the anticodon UAC in the 3' to 5' orientation.

### Final Answer:
The first translated codon in any mRNA binds to the anticodon **3'-UAC-5'**.