TRANSCRIPTION Flashcards
3 parts to the central dogma- All cells…
- store genetic code information in DNA
- use transcription
- use translation
Transcription
Transfer the genetic code information in DNA to an RNA molecule called a messenger RNA
Translation
Convert the genetic code information in the messenger RNA into the protein the cell needs
The genetic code consists of the
Genetic alphabet (A, C, G, T) and the genetic code words (codons)
Language of life
All species use the genetic code/set of rules to
- store genetic instructions in DNA
- use these instructions to make all the proteins they require
The linear sequence of codons, also called triplets, in the gene’s coding region determines….
Determines the linear sequence of amino acids in the protein the gene encodes
Each codon in the gene consists of
Three consecutive nucleotides that correspond to one of the 20 types of amino acids
What are the codons
The 64 “genetic code words” that form nature’s remarkable genetic langauge
Nature arranges the four nucleotides (A, C, G, T) that form DNA into all possible combinations to form
64 genetic code words
The genetic code is _______ among all life
Universal
Cells use ________ to begin accessing the genetic instructions in a gene to make the protein the gene encodes
Transcription
The cell must ______ (______) the gene when it needs the protein the gene encodes
Express (activate)
Transcription
Makes an RNA copy of the gene called a messenger RNA (mRNA) or transcript
mRNA
Is a copy of the gene’s coding strand
It contains the nucleotide sequence that determines the amino acid sequence of the protein the gene encodes
RNA polymerase synthesizes
the messenger RNA molecule during transcription
RNA Polymerase reads the
nucleotide sequence of the gene’s non-coding (template) strand
-it follows the rules of complementary base pairing when linking the ribonucleotides together
-Proof reading ability
The nucleotide uracil replaces _____ in mRNA
Thymine
RNA polymerase IV and V
Makes small RNAs in plants
How many phases in transcription
3
Initiation phase
Begins when the cell receives the signal to express (activate) the gene
-The transcription initiation complex is assembled, positioned, and activated at the promoter
-The complex is formed from the general transcription factors and RNA polymerase binding to each other and to the promoter
Elongation phase
RNA polymerase synthesizes messenger RNA at the transcription start site
-RNA polymerase bonds the ribonucleotides together to make mRNA
Termination phase
Occurs when RNA polymerase reaches the transcription stop site sequence
-RNA polymerase pauses and stops mRNA synthesis
-RNA polymerase moves ~10-35 nucleotides past the transcription stop site
-RNA polymerase releases the mRNA molecule
Termination phase is also called
Poly-Adenylation signal
Termination sequence
