Nonsense codons

Definition

Nonsense codons are sequences of DNA that signal the termination of protein synthesis. They do not encode amino acids and cause translation to stop.

5 Must Know Facts For Your Next Test

1. Nonsense codons are also known as stop codons.
2. The three nonsense codons in the genetic code are UAA, UAG, and UGA.
3. These codons do not correspond to any tRNA molecules.
4. Nonsense codons are crucial for defining the end of mRNA translation.
5. A mutation that introduces a premature nonsense codon can result in a truncated, nonfunctional protein.

Review Questions

• What are the three nonsense codons?
• Why are nonsense codons important in protein synthesis?
• What happens if a premature nonsense codon is introduced into a gene sequence?

Related terms

Codon: A set of three nucleotides on mRNA that codes for a specific amino acid or signals termination.

Translation: The process by which ribosomes synthesize proteins using mRNA as a template.

Mutation: A change in the DNA sequence that can alter genetic information and potentially affect protein function.