Khorana & his collegeous synthesized an RNA molecule with repeating sequence of `U G N_(2-)` bases. The RNA with "UGU GUG UGU GUG" produced at tetra peptide with alternating sequences of cystein and valine. This prove that codon for cystein & valine is

Options

A. UGG, GUU
B. UUG, GGU
C. UGU & GUG
D. GUG & UGU

Answer

To solve the question regarding the codons for cysteine and valine based on the synthesized RNA sequence, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Identify the RNA Sequence**: The synthesized RNA molecule has a repeating sequence of `UGU GUG UGU GUG`.

2. **Understand the Structure of the Tetra Peptide**: The RNA sequence produces a tetrapeptide with alternating sequences of cysteine and valine. This means that the first amino acid is cysteine, the second is valine, the third is cysteine, and the fourth is valine.

3. **Determine the Codons**:
- The codon for cysteine is represented by the sequence `UGU`.
- The codon for valine is represented by the sequence `GUG`.

4. **Confirm the Codons**:
- The sequence `UGU` corresponds to cysteine.
- The sequence `GUG` corresponds to valine.

5. **Conclusion**: Therefore, the codons for cysteine and valine are `UGU` and `GUG`, respectively.

### Final Answer:
The codon for cysteine is UGU and for valine is GUG.