CHAPTER 13 Translation of mRNA
3’– Untranslated Region 3’–UTR; the region of an mRNA that is downstream
from the stop codon, follows the codons thar are
translated into an amino acid sequence within a
polypeptide
5’– Untranslated Region 5’–UTR; the region at the 5’ end that precedes the
codons that are translated into an amino acid sequence
within a polypeptide
A-Site Aminoacyl site of a translation tRNA and mRNA unit
Adaptor Hypothesis The position of an amino acid within a polypeptide is
determined by the binding between the mRNA and an
adaptor molecule (tRNA) carrying a specific amino acid
Aminoacyl-tRNA Synthesase Enzyme that catalyzes the attachment of a specific
amino acid to the correct tRNA
Amino-Terminus N-Terminus; first amino acid of the polypeptide. An
amino group (NH3⁺) is found at this site; there is a
nitrogen atom present. The first amino acid is specified
by a codon that is near the 5’ end of the mRNA
Antibiotic Any substance produced by a microorganism that
inhibits the growth of other microorganisms, such as
pathogenic bacteria
Anticodon Three nucleotide sequences that are complementary to
codons in mRNA
Carboxyl-Terminus C-Terminus; last amino acid in a completed
polypeptide. A carboxyl group (COO−) is always found
at this site in the polypeptide. The last amino acid is
specified by a codon near the 3’ end of the mRNA
Cell-Free Translation System Experimental mixture that can synthesize polypeptides
Charged tRNA A tRNA that has an amino acid attached to its 3’ end by
a covalent bond
Degeneracy More than one codon specifies the same amino acid
E Site Exit site of a translation tRNA and mRNA unit
, Inborn Error of Metabolism Genetic disease, involves defects in a metabolic enzyme
Isoacceptor tRNAs Two or more tRNAs that differ at the wobble position
but can recognize the same codon
One-Gene/One-Enzyme
The idea that one gene encodes one enzyme
Hypothesis
P Site Peptidyl site of a translation tRNA and mRNA unit
Peptide Bond
Bond between the carboxyl group in the last amino acid
of the polypeptide and the amino group in the amino
acid being added. This happens via a condensation
reaction that releases a water molecule
Peptidyl Transferase Complex that functions during translation to catalyze
the formation of a peptide bond between the amino acid
in the ribosomal A-site and the growing polypeptide
Polypeptide Synthesis during Polypeptides can elongate at a rate of 15–20 amino
Elongation acids per second in bacteria or 2–6 amino acids per
second in eukaryotes. There are three stages:
1) charged tRNA binding to A site
2) Peptidyl transfer reaction
3) Translocation
Polyribosome/Polysome An mRNA transcript that has many bound ribosomes in
the act of translation
Primary Structure The linear sequence of amino acids that forms a
polypeptide
Protein Functional unit that can be composed of one or more
polypeptides
Quaternary Structure Two or more polypeptides that associate with each
other. The individual polypeptides are called subunits
and each has their own tertiary structure
3’– Untranslated Region 3’–UTR; the region of an mRNA that is downstream
from the stop codon, follows the codons thar are
translated into an amino acid sequence within a
polypeptide
5’– Untranslated Region 5’–UTR; the region at the 5’ end that precedes the
codons that are translated into an amino acid sequence
within a polypeptide
A-Site Aminoacyl site of a translation tRNA and mRNA unit
Adaptor Hypothesis The position of an amino acid within a polypeptide is
determined by the binding between the mRNA and an
adaptor molecule (tRNA) carrying a specific amino acid
Aminoacyl-tRNA Synthesase Enzyme that catalyzes the attachment of a specific
amino acid to the correct tRNA
Amino-Terminus N-Terminus; first amino acid of the polypeptide. An
amino group (NH3⁺) is found at this site; there is a
nitrogen atom present. The first amino acid is specified
by a codon that is near the 5’ end of the mRNA
Antibiotic Any substance produced by a microorganism that
inhibits the growth of other microorganisms, such as
pathogenic bacteria
Anticodon Three nucleotide sequences that are complementary to
codons in mRNA
Carboxyl-Terminus C-Terminus; last amino acid in a completed
polypeptide. A carboxyl group (COO−) is always found
at this site in the polypeptide. The last amino acid is
specified by a codon near the 3’ end of the mRNA
Cell-Free Translation System Experimental mixture that can synthesize polypeptides
Charged tRNA A tRNA that has an amino acid attached to its 3’ end by
a covalent bond
Degeneracy More than one codon specifies the same amino acid
E Site Exit site of a translation tRNA and mRNA unit
, Inborn Error of Metabolism Genetic disease, involves defects in a metabolic enzyme
Isoacceptor tRNAs Two or more tRNAs that differ at the wobble position
but can recognize the same codon
One-Gene/One-Enzyme
The idea that one gene encodes one enzyme
Hypothesis
P Site Peptidyl site of a translation tRNA and mRNA unit
Peptide Bond
Bond between the carboxyl group in the last amino acid
of the polypeptide and the amino group in the amino
acid being added. This happens via a condensation
reaction that releases a water molecule
Peptidyl Transferase Complex that functions during translation to catalyze
the formation of a peptide bond between the amino acid
in the ribosomal A-site and the growing polypeptide
Polypeptide Synthesis during Polypeptides can elongate at a rate of 15–20 amino
Elongation acids per second in bacteria or 2–6 amino acids per
second in eukaryotes. There are three stages:
1) charged tRNA binding to A site
2) Peptidyl transfer reaction
3) Translocation
Polyribosome/Polysome An mRNA transcript that has many bound ribosomes in
the act of translation
Primary Structure The linear sequence of amino acids that forms a
polypeptide
Protein Functional unit that can be composed of one or more
polypeptides
Quaternary Structure Two or more polypeptides that associate with each
other. The individual polypeptides are called subunits
and each has their own tertiary structure
