Steps of Translation - Madison Public Schools
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Transcript Steps of Translation - Madison Public Schools
Steps of Translation
Honors Biology
Monkemeier
Friday, April 8, 2016
Initiation
Large subunit and small subunit of the
ribosomes come together.
When the subunits come together they
form a “stage” with 2-3 “seats”
mRNA threads itself in between the large
and small subunits.
A tRNA carrying Methionine checks its
anticodon to the codon on the mRNA. The
anticodon and codon are complementary to
each other.
Initiation – What is not shown?
Initiation Complete
Elongation
Another tRNA carrying an amino acid matches its
anticodon complementary to the codon on the mRNA.
A peptide bond is formed between methionine and the
new amino acid.
The Ribosome moves over one codon on the mRNA.
The original tRNA carrying methionine goes away.
Another tRNA carrying an amino acid comes in and
matches its anticodon complementary to the codon on
the mRNA (newly exposed)
A peptide bond forms between the two amino acids.
The ribosome moves over one codon
PROCESS CONTINUES
Elongation
Termination
A stop codon appears in the “A” site
on the ribosome.
tRNA carrying the polypeptide falls
off.
The large and small subunits of the
ribosome break apart.
A newly formed polypeptide strand is
formed.
Protein Formation
Remember that there are four levels of
protein structure.
Translation forms the first level of protein
structure – the polypeptide chain
Secondary structure involves hydrogen
boding of the chain to form alpha helix or
beta pleated sheet
Tertiary structure includes more bonding
between the chain – Ex: Sulfur bridges
Quarternary structure: several chains
together.