Third-base wobble allows some tRNAs to recognize more than one mRNA codon. Based on this chapter's discussion of wobble, what is the minimal number of tRNA molecules necessary to recognize the following amino acids?
Leucine

Verified step by step guidance

1. Understand the concept of wobble: Wobble refers to the flexibility in base pairing at the third position of the codon, allowing a single tRNA to recognize multiple codons. This is due to non-standard base pairing rules at the third position.
2. Identify the codons for leucine: Leucine is encoded by six codons in the genetic code: UUA, UUG, CUU, CUC, CUA, and CUG.
3. Group the codons based on wobble compatibility: The codons can be grouped based on their third-base wobble pairing. For example, UUA and UUG can be recognized by one tRNA, while CUU, CUC, CUA, and CUG can be recognized by another tRNA.
4. Determine the minimal number of tRNAs: Analyze the wobble rules and groupings to determine how many distinct tRNAs are required to recognize all six codons for leucine. Consider the base pairing flexibility at the third position.
5. Conclude the minimal number of tRNAs: Based on the grouping and wobble rules, calculate the minimal number of tRNAs necessary to recognize all leucine codons without specifying the final number.

Key Concepts

Wobble Hypothesis

The wobble hypothesis explains how the third position of a codon can pair with multiple tRNA anticodons, allowing a single tRNA to recognize more than one codon. This flexibility in base pairing is crucial for efficient protein synthesis, as it reduces the number of tRNA molecules needed to translate the genetic code.

Codons and Amino Acids

Codons are sequences of three nucleotides in mRNA that specify particular amino acids during protein synthesis. Each amino acid can be encoded by multiple codons, which is particularly true for leucine, which has six different codons. Understanding the relationship between codons and their corresponding amino acids is essential for determining the number of tRNAs required.

tRNA Molecules

Transfer RNA (tRNA) molecules are responsible for bringing the appropriate amino acids to the ribosome during translation. Each tRNA is specific to one amino acid and can recognize one or more codons due to the wobble effect. The number of distinct tRNA molecules needed depends on the number of unique codons for a given amino acid, factoring in wobble pairing.