Chapter 14- Gene Expression Flashcards
Transcription
Synthesis of RNA using information in the DNA
Gene Express
The process in which DNA directs the synthesis of proteins
mRNA
Strand of RNA that carries genetic message from DNA to protein synthesizing part of cell
Translation
Synthesis of a polypeptide using the information in mRNA
Ribosome
Complex of particles that facilitate the orderly linking of amino acids to polypeptide chains
Primary Transcipt
The initial part of RNA that is not translated into a protein
Triplet Code
Genetic instruction for a polypeptide chai written in three nucleotide words
Template strands
Provides pattern or template for the sequence of nucleotides in a RNA transcript
Codon
mRNA nucleotide triplet
Reading frame
The triplet grouping of ribonucleotides used by translation machinery
RNA polymerase
Pries apart the stand of DNA and makes RNA form free floating nucleotides, complementary to DNA
Promoter
DNA sequence where RNA polymerase attaches and begins its thing
Terminator
The part of RNA that ends the transcription
Transcription unit
Stretch of DNA that is transcribed into a RNA molecule
Transcription factors
Collection of proteins that mediate the binding of RNA polymerase and initiation of transcription
Transcription initiation complex
Complex of RNA polymerase and transcription factors bound the promoter
TATA box
In forming the initiation at complex at a eukaryotic promoter
Poly-A tail
At the 3’ end, an enzyme adds 50-250 adds adenine nucleotides
RNA processing
Both ends of primary transcripts are altered by enzymes in Eukaryotes before the genetic messages are dispatch to the cytoplasm
5’ cap
A modified form of guanine nucleotide added I tot the 5’ end after transcription of first 20-49 nucleotides
RNA splicing
A cut and paste job of a large removal of RNA molecules that is originally synthesized
Introns
The noncoding segments of nucleic acid that lies between coding regions
Exons
The coding regions of the DNA that is expressed
Alternative RNA Splicing
Genes that give rise to two or more different polypeptide depending on which segments are treated as exons during RNA processing
Spliceosome
A large complex of proteins and small RNA that remove introns
Ribozymes
RNA molecules that function as enzymes
tRNA
The function of tRNA is to transfer amino acids from the cytoplasmic pool of amino acids
Anticodon
The particular nucleotide triplet that base pairs to a specific mRNA codon
Aminoacyl-tRNA synthetases
The correct matching up if tRNA and amino acids is carried out ha family of related enzymes
Wobble
Flexible base pairing at the 5’ end of tRNA anticodon can pair with either a or g at the Thrid position
rRNA
What the anti codons are made out of
P site
Where the amino acid binds to polypeptide
A site
Point where the tRNA is added
E site
Exit site
Signal peptide
The polypeptides of proteins that are destined for the endomembrane
Signal recognition particle
Functions as an escort that brings ribosome to receptor in er membrane
Point mutations
Change in a single nucleotide pair of gene
Nucleotide pair substitution
Replacement of one nucleotide and its partner
Silent mutations
No effect on the phenotype
Missesne mutations
Change one amino acid to another and have little effects on the protein
Nonsense mutations
Causes translations to be canceled and stops the polypeptide and make the
Insertions
Addition of nucleotide
Deletion
Loss of nucleotide
Frame shift mutation
When the points where the codon are placed are moved
Mutagen
Interact with DNA and cause mutations
