Khorana and his colleagues sythesized RNA molecule with repeating sequences of `UG N_(2)`-base the RNA with `"UGU" "GUG" "UGU" "GUG"` produced a tetrapeptide with alternating sequence of cystein and valine, this prove that codon for cystein and valine is

Options

A. (a) UGG & GUU
B. (b) UUG & GGU
C. (c) UGU & GUG
D. (d) GUG & UGU

Answer

To solve the question regarding the codons for cysteine and valine based on the RNA sequence synthesized by Khorana and his colleagues, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the RNA Sequence**: The RNA molecule synthesized has a repeating sequence of "UG" which leads to the formation of codons. The specific sequence given is "UGU GUG UGU GUG".

2. **Identify the Codons**: Break down the RNA sequence into codons (groups of three nucleotides):
- First codon: UGU
- Second codon: GUG
- Third codon: UGU
- Fourth codon: GUG

3. **Refer to the Codon Chart**: Use a codon chart to determine which amino acids correspond to the codons identified:
- UGU codes for Cysteine (Cys)
- GUG codes for Valine (Val)

4. **Recognize the Pattern**: The sequence alternates between UGU (Cysteine) and GUG (Valine), confirming that the synthesized RNA produces a tetrapeptide with alternating sequences of these two amino acids.

5. **Conclude the Codons**: Based on the analysis, the codons for Cysteine and Valine are UGU and GUG, respectively.

### Final Answer:
The codons for Cysteine and Valine are **UGU and GUG**.

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