Translation is the process by which a cell decodes the nucleotide sequence of messenger RNA (mRNA) to build a polypeptide. This lesson introduces the molecules that make translation possible and explains how the genetic code connects mRNA codons to amino acids.
Translation requires an mRNA template, ribosomes, tRNAs, and various enzymatic factors. Although the precise composition of these components can differ among species, their general roles are similar across organisms.
All flashcards
What is translation?
Translation is the process of decoding an mRNA sequence to assemble amino acids into a polypeptide.
What are the main roles of the ribosomal subunits?
The small subunit binds the mRNA template. The large subunit coordinates tRNAs and contributes to forming the polypeptide.
What does a tRNA do?
A tRNA acts as an adaptor: it recognizes an mRNA codon and brings the corresponding amino acid to the ribosome.
What does it mean for a tRNA to be charged?
A charged tRNA has been bonded to its correct amino acid and is ready to deliver it during translation.
Which codons signal the start and end of translation?
AUG commonly serves as the start codon and specifies methionine. UAA, UAG, and UGA are stop codons.
Quiz questions
What is the primary role of the small ribosomal subunit during translation?Answer: It binds the mRNA template.
Which ribosomal site accepts an incoming charged tRNA during elongation?Answer: The A site.
What happens when a stop codon enters the ribosome's decoding position?Answer: It triggers release of the completed polypeptide.
What role does GTP play in translation?Answer: It provides energy for steps in the process.
Why can different codons specify the same amino acid?Answer: There are more possible codons than commonly occurring amino acids.
Based on Concepts of Biology by Samantha Fowler, Rebecca Roush, James Wise (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.