Answer: Flexible base pairing at the third codon position allowing one tRNA to recognize multiple codons.
- A Mispairing that sometimes occurs between the mRNA transcript and the template DNA strand in many documented cases
- B Flexible base pairing at the third codon position allowing one tRNA to recognize multiple codons
- C Largely random, non-specific binding occurring between any codon and any anticodon according to conventional understanding
- D Lateral sliding of the ribosome along the mRNA strand without proper translocation in routine practice
Correct answer: B. Flexible base pairing at the third codon position allowing one tRNA to recognize multiple codons
Explanation: Wobble hypothesis (Crick): the third position of the codon can form non-Watson-Crick base pairs. This allows one tRNA anticodon to recognize multiple codons differing at the third position, reducing the number of tRNAs needed.
As substrate concentration rises, reaction rate increases steeply at first, then plateaus at Vmax once every enzyme molecule is working at full capacity; Km is the substrate concentration giving half-maximal rate, and a LOWER Km means the enzyme reaches that rate with less substrate (higher affinity).
Concept context
Carbohydrates, proteins, lipids, nucleic acids, and enzyme kinetics. Essential foundation for understanding metabolism.