Video Transcript
What is the purpose of tRNA in the
process of translation? (A) To provide the site within a
eukaryotic cell for translation to take place. (B) To carry amino acids to the
mRNA molecule being translated to form a polypeptide chain. (C) To catalyze the formation of
peptide bonds between amino acids in a polypeptide chain. Or (D) to provide the sequence of
nucleotides that determine the sequence of amino acids.
This question is asking us about
the purpose of tRNA during translation. To answer this question, let’s
first clear the answer choices so we have more room to work with. In order for a gene in our DNA to
be expressed and its protein made, it must first be transcribed or copied to form
mRNA. This process is called
transcription. This mRNA can then be translated to
form a protein. This process is called translation,
and it involves a few key components, namely, mRNA, a special organelle called the
ribosome, and tRNA. Let’s look at these in a little bit
more detail.
mRNA is a copy of a gene that’s
being expressed. It contains a nucleotide sequence
that contains the information needed for building a protein. Groups of three nucleotides, called
codons, can be decoded or translated to their corresponding amino acid. So the codon CGG corresponds to the
amino acid arginine. These nucleotides, when organized
into codons, can code for any amino acid in a protein. These amino acids are held together
by peptide bonds. The resulting polypeptide can then
fold into a protein.
mRNA can be translated in a special
complex called the ribosome. This molecular machine is able to
match the nucleotide sequence of mRNA with the corresponding amino acid. The ribosome can then form peptide
bonds between these amino acids and form the polypeptide. Finally, tRNA, or transfer RNA, is
a special adapter molecule that brings amino acids to the ribosome. Here, they’re matched to their
corresponding nucleotide sequence.
Therefore, the purpose of tRNA in
the process of translation is to carry amino acids to the mRNA molecule being
translated to form a polypeptide chain.
