Genetic Code
Terms
Amino Acid
-
The building block of proteins.
Codon
-
A three-nucleotide sequence in an mRNA sequence. Used to specify an amino
acid.
Degenerate
-
Term used to describe the genetic code. Means that more than one codon can
specify for a single amino acid.
Extragenic supression
-
A type of mutation that occurs outside of the genetic code, but has an
effect on the amino acid sequence that is translated from the genetic code.
Frameshift mutation
-
One class of genetic code mutation that results from the insertion or
deletion of a nucleotide to an mRNA sequence. Results in a new reading
frame.
Genetic Code
-
The series of codons that make up an organism's DNA.
Intragenic suppression
-
A type of mutation that occurs within the genetic code to suppress a
different mutation.
Missense mutation
-
One class of genetic code mutation that results from the substitution of one
base group for another in a codon. Results in the change of the amino acid
for which the codon specifies.
Mutation
-
An error in the genetic code caused most often by a the incorrect substitution,
insertion, or deletion of a nucleotide.
Nonsense mutation
-
One class of genetic code mutation that results from the substitution of one
base group for another in a codon. Results in a stop codon, a codon
that can no longer be recognized by tRNA molecules.
Reading frame
-
One of three possible ways of grouping an mRNA sequence by threes to yield an
amino acid sequence.
Silent Mutation
-
A substitution base mutation that changes a codon, but because of degeneracy does not change the amino acid that codon specifies.
Stop codon
-
A codon that is not recognized by a tRNA molecule. One of three codons:
UAA, UAG, or UGA. Signals the termination of DNA
translation.
Suppressor mutation
-
A type of genetic code mutation that alters the result of a different
mutation. Can be either extragenic or intragenic.
Synonyms
-
Codons that code for the same amino acid.
True reversion
-
One type of suppression mutation that leads to the restoration of the
natural genetic code sequence.
