CHAPTER 17 Flashcards
The process by which DNA directs protein Synthesis
Gene Expression
2 stages of gene expression
Transcription and translation
Is the synthesis of RNA using information in DNA
Transcription
What does Transcription produce?
mRNA (Messenger RNA)
Is the synthesis of Polypeptide using information in the mRNA
Translation
Are the sites of translation
Ribosomes
What does the transcription of a protein-coding eukaryotic gene results in?
pre-mRNA
Is the initial RNA transcript from any gene prior to processing
Primary Transcript
What is the cellular COC
DNA - RNA - PROTEIN
Pries the DNA strands apart and joins together the RNA nucleotides
RNA Polymerase
The DNA sequence where RNA polymerase attaches to is called the?
Promoter
In bacteria, the sequence signaling the end of transcription is called the?
Terminator
The stretch of DNA the is transcribed is called the?
Transcription Unit
What is the Promoter Called
TATA box
Mediate the binding of RNA polymerase
Transcription Factors
What is the start point, TATA box, and Transcription factors collectively called?
Transcription initiation Complex
What modified nucleotide does a 5’ end receive?
5’ cap
What modified nucleotide does a 3’ end receive?
Poly-A tail
The noncoding regions, also called intervening sequences
Introns
Also called the other regions
Exons
Removes introns and joins exons, creating mRNA molecule with a continuous coding sequence
RNA Splicing
A cell translates an mRNA message into protein with the help of the?
tRNA (Transfer RNA)
A correct match of between tRNA and an amino acid is done by what enzyme?
aminoacyl-tRNA synthetase
Flexible pairing at the third base at a codon is called the?
Wobble
The two Ribosomal subunits are made up of proteins and?
rRNA (Ribosomal RNA)
Hold the tRNA that carries the polypeptide chain
P-site
Holds the tRNA that carries the next amino acid to be added to the chain
A-site
Is the exit site where discharged tRNA’s leaves the ribosomes
E-site
What are the 3 stages of translation
Initiation, Elongation and Termination
During elongation, amino acids are added one by one to the _______ of the growing chain
C-Terminus
Multiple Ribosomes can translate a single mRNA simultaneously forming a?
Polysome
Enables a cell to make copies of a polypeptide very quickly
Polyribosomes
Are changes of the genetic information of the cell
Mutations
Are changes in just one-nucleotide pair of genes
Point Mutations
Replaces one nucleotide and its partner with another pair of Nucleotides
Nucleotide-Pair Substitution
Have no effect on the amino acid produced by a codon because of redundancy of the genetic code
Silent Mutation
Still code for amino acid but not correct amino acid
Missense Mutation
Change an amino acid codon into a stop codon: most lead to a nonfunctional protein
Nonsense Mutation
are additions or losses on nucleotide pairs in a gene
Insertions and Deletions
Insertions or Deletions may alter the reading frame producing a what?
Frameshift Mutation
Are physical or chemical agents that can cause mutation
Mutagens
A series of Nonoverlapping , three nucleotide words
Triplet Code
