An experiment by Khorana and his colleagues translated a synthetic mRNA containing repeats of the trinucelotide UUG.
What is the result obtained from each reading frame?

Verified step by step guidance

1. Understand the problem: The synthetic mRNA contains repeats of the trinucleotide UUG. Translation occurs in three possible reading frames, and each frame determines the sequence of codons that are read to produce amino acids.
2. Step 1: Write out the sequence of the synthetic mRNA. Since it contains repeats of UUG, the sequence can be represented as UUGUUGUUGUUG... (repeating indefinitely).
3. Step 2: Identify the codons in the first reading frame. Start reading from the first nucleotide (U) and group the sequence into codons of three nucleotides each: UUG, UUG, UUG, etc.
4. Step 3: Identify the codons in the second reading frame. Start reading from the second nucleotide (U) and group the sequence into codons of three nucleotides each: UGU, UGU, UGU, etc.
5. Step 4: Identify the codons in the third reading frame. Start reading from the third nucleotide (G) and group the sequence into codons of three nucleotides each: GUU, GUU, GUU, etc.

Key Concepts

mRNA Translation

mRNA translation is the process by which ribosomes synthesize proteins based on the sequence of nucleotides in messenger RNA (mRNA). Each set of three nucleotides, known as a codon, corresponds to a specific amino acid. Understanding this process is crucial for interpreting the results of experiments involving synthetic mRNA, as it directly affects the resulting protein structure and function.

Reading Frames

A reading frame refers to the way nucleotides in mRNA are grouped into codons during translation. There are three possible reading frames for any given mRNA sequence, depending on where translation begins. Each reading frame can produce a different sequence of amino acids, leading to distinct proteins, which is essential for analyzing the outcomes of experiments like those conducted by Khorana.

Trinucleotide Repeats

Trinucleotide repeats are sequences of three nucleotides that are repeated multiple times in a row within a DNA or RNA strand. In the context of Khorana's experiment, the synthetic mRNA containing repeats of UUG would lead to the same codon being read multiple times, affecting the resulting protein's amino acid sequence. This concept is important for understanding how specific sequences influence protein synthesis and function.