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Translation Notes
4a. The general pathway by which
ribosomes synthesize proteins, using
tRNAs to translate genetic information
in mRNA.
Objectives
• Identify the three kinds of RNA and their
functions.
• Describe how mRNA codons are
translated into amino acids.
• Summarize the process of protein
synthesis.
Vocabulary
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Translation
Codon
Ribosomal RNA (rRNA)
Transfer RNA (tRNA)
Anticodon
Amino acids are coded by mRNA base
sequences.
Translation
• Process that converts, or translates, an
mRNA message into a polypeptide.
Codon
• Three-nucleotide sequence that codes for
an amino acid.
The genetic code matches each mRNA
codon with its amino acid or function.
Codons are read as a series of three
nonoverlapping nucleotides. A change in
the reading frame changes the resulting
protein.
(Figure on board)
Amino acids are linked to become a protein.
Ribosomal RNA (rRNA)
• Forms part of ribosomes, a cell’s protein
factories.
Ribosomes – The large and small ribosomal
subunits pull mRNA through the ribosome,
reading it one codon at a time.
(Figure on board)
Transfer RNA (tRNA)
• Brings amino acids from the cytoplasm to
a ribosome to help make the growing
protein.
tRNA – One end of the tRNA has an
anticodon that recognizes an mRNA
codon. The other end is attached to an
amino acid.
(Figure on board)
Anticodon
• Set of three nucleotides that is
complimentary to an mRNA codon.
Translation converts an mRNA transcript into
a polypeptide. The process consists of
three repeating steps.
(Figure on board)