Translation Flashcards
Use of mRNA as a template for polypeptide production
Translation
Each amino acid contains:
-Amino terminus
-Carboxyl terminus
-R side groups
-Peptide bond linkages
Each polypeptide contains:
-Amino terminus
-Carboxy terminus
Direct relationship between the linear sequence of nucleotide bases within a gene (the DNA) and the primary structure of the protein the gene codes for
Colinearity
Unit of three nucleotide bases in mRNA that specified an amino acid
Codon
Complete set of codons; amino acid relationships found universally in living organisms
Genetic code
There are 64 codons and 20 amino acids. Therefore there is ____ within the genetic code
Redundancy
3rd codon does not necessarily attach to the tRNA, and may only be used for small variations in nucleotides
Wobble Hypothesis
The three initiation factors of translation are:
- mRNA attached by a 30s ribosome subunit
- tRNA carrying MET attaches to mRNA
- Next subunit (50s) of ribosome attaches
The ribosome shifts toward the 3’ end of the messenger RNA
Translocation
mRNA is read in the ___ direction (opposite of replication or transcription)
5’ to 3’
The ribosome pauses at a designated ___ codon, and the components which assembled during initiation dissassemble
Stop
In prokaryotes, translation begins ___ the mRNA is actually completely synthesized
Before
Heritable change in an organism’s genetic composition
Mutation
Single nucleotide mutation
Point mutation
Mutation in major portion of the chromosome
Cytogenetic Aberrations
Purine to Purine (or Pyrimidine to Pyrimidine) mutation
Transition
Purine to Pyrimidine mutation
Transversion
Due to degenerate code, no change in function
Silent
One switch with a broad range of phenotypic effects
Missense
Creation of a stop codon
Nonsense
Addition or deletion of nucleotides. Affects all codons and is detrimental to the function of the protein/phenotypic development
Frameshift
Up-promoter mutations ___ the consensus sequence, enhancing transcription
Perfect
Down-promoter mutations add ____ to the consensus sequence and reduce transcription
Irregularities
Reduces survival, short term, reduces reproductive ability
Deleterious
Is the cause of death of the organism
Lethal
Improves reproductive ability. Improved health/survival, short term
Beneficial
The effect is limited to very specific environmental conditions: i.e, a certain temperature range
Conditional
One tissue area will express this mutation, not all the cells of the organism
Mosaic Expression
Occurs in a cell that cannot produce a gamete
Somatic Cell Mutation
Occurs in the production of a gamete, or in an oogonium or spermatogonium
Germ Line mutation
The entire organism will express this mutation
Constitutional Expression
