MLSBIO101 TRANSCRIPTION AND TRANSLATION Flashcards
What is the synthesis of single stranded RNA from a double stranded DNA template?
Transcription
What is produced in transcription?
mRNA
What is the first stage of protein biosynthesis from RNA?
Translation
In translation, what is formed by using mRNA template?
Polypeptide
In translation, where does the formation of polypeptide occur?
Ribosomes
What are the two processes that is part of gene expression?
- Transcription
- Translation
What part of the eukaryotic cell separates transcription from translation?
Nuclear Envelope
What kind of processing occurs in the nucleus?
Extensive RNA Processing
What is the synthesis of mRNA from a DNA template which occurs in the 5’ –> 3’ direction?
Transcription
What direction does transcription occur?
5’ –> 3’
In transcription, what enzyme reads the DNA sequence to produce a complementary and antiparallel RNA strand?
RNA Polymerase
In transcription, what are the two strands does the RNA polymerase produce by reading the DNA sequence?
- Complementary Strand
- Antiparallel RNA strand
What is the first step leading to gene expression?
Transcription
What do you call the stretch of DNA transcribed into an RNA molecule?
Transcription Unit
A transcription unit is encoded to?
At least one gene
What is the result of transcription?
mRNA
What is used to create proteins via the process of translation?
mRNA
What are the three stages of Transcription?
- Initiation
- Elongation
- Termination
In Initiation, what enzyme binds to specific DNA region and initiate transcription called as promoter site?
RNA Polymerase
In Initiation, what do you call the site where the RNA polymerase is bonded to a specific DNA region and initiates transcription?
Promoter Site
In Initiation, what is the enzyme responsible for transcription?
RNA Polymerase
What are the 5 units of the RNA polymerase?
- 2 a subunits
- B subunit
- B’ subunit
- w subunit
In Initiation, what do you call the position of the first synthesized base of the RNA?
Start Site
In Elongation, what moves along the DNA template and sequentially synthesizes the RNA chain?
RNA polymerase
DNA unwinds ahead of the moving polymerase and the helix is reformed behind it. How many bases are unwinded at a time?
10-20 DNA bases
In Elongation, on what direction does the RNA polymerase add nucleotides?
5’ –> 3’
In termination, what do you call the part where transcription stops when RNA polymerase reaches a section of the DNA?
Terminator
What is the terminator sequence?
AAUAAA
When the RNA strand is release, what dissociates from the DNA?
RNA Polymerase
What do you call the original transcript from the DNA?
Pre-mRNA
What type of RNA contains transcript of both introns and exons?
Pre-mRNA
What is the non-coding sections of nucleic acid found between coding regions?
Introns
What is the coding regions of nucleic acids?
Exons
T/F. Pre-mRNA never leaves the cell’s nucleus.
True
What happens to the introns to form mRNA?
Excised
What happens to exons to form mRNA?
Joined
What is the process called where introns are removed to produce mRNA?
Splicing
What do you call the process in which the formation of polypeptide by decoding mRNA produced in transcription?
Translation
Where does translation occur?
Ribosomes
T/F. Are ribosomes present in the cytoplasm?
True
T/F. Does translation begins after mRNA enters the cytoplasm?
True
What is type of RNA is the interpreter of mRNA?
tRNA
What are the four phases of translation?
- Initiation
- Elongation
- Translocation
- Termination
What does the initiation stage of translation brings together?
mRNA
In initiation, what are the two things that bears the first amino acid of the polypeptide?
tRNA and two subunits of ribosomes
What are the five components involved in the initiation of translation?
- Large and Small subunits of ribosome
- mRNA
- Initiator tRNA (Charged form)
- Three Factors (IF1, IF2, IF3)
- GTP
What do you call the tRNA that has an amino acid linked?
Charged tRNA
What factor/s are bound to free 30S subunit?
IF1 and IF2
What factor/s are complexed with GTP then bind to the small subunit?
IF3
What factor/s assist the charged initiator tRNA to bind?
IF3
How many binding sites of tRNA does the assembled ribosome have?
2 tRNA binding sites
What do you call the two tRNA binding sites assembled in the ribosome?
- A-site (Acceptor) for Aminoacyl
- P-site (Donor) for polypeptide
What site is where the incoming aminoacyl-tRNA molecules bind?
A-site
What do you call the site of the growing polypeptide chain?
P-site
What is the major outcome of initiation?
Placement of initiator tRNA in the P-site
What is the start codon?
AUG
What is the start anticodon?
UAC
On what end does the small ribosomal subunit attaches to?
5’ end of mRNA
In Elongation, what do you call where the amino acid are added one by one to the first amino acid?
Amino acid delivery
What do you call the recognition where mRNA codon in the A site forms hydrogen bond with the tRNA anticodon?
Codon Recognition
In Codon Recognition, what bond is formed by the mRNA codon and the tRNA anticodon?
Hydrogen Bonds
In peptide bond formation, what catalyzes the formation of peptide bonds between the amino acids?
Ribosome
What are the three elongation factors?
- EF-T4
- EF-T5
- EF-G
Where does the three elongation factors bind to?
GTP or GDP
What do you call the process of the tRNA with the polypeptide chain in the A site is translocated to the P site?
Translocation
Where does the tRNA at the P site moves to before leaving the ribosome?
E site
On what direction does the ribosome moves down the mRNA?
5’ –> 3’
What do you call the process where protein factors interact with the stop codons and cause release of the completed polypeptide chain?
Termination
What is the name of the protein factor involved in termination?
Release Factors
What are the three stop codons?
- UAA
- UAG
- UGA
What are the two codons recognized by RF1?
- UAA
- UAG
What are the two codons recognized by RF2?
- UAA
- UGA
What factor helps either RF1 and RF2 to carry out the reaction?
RF3
How many initiation factors do eukaryotes have?
9 IF
T/F. Eukaryotic initiator tRNA does not become formylated as in prokaryotes.
True
What are the three factors involved in elongation in eukaryotes?
- eEF1a
- eEF1b
- eEFz
How many release factors in termination do eukaryotes have?
One
What is the name of the release factor in eukaryotes?
eRF
T/F. Does the eRF recognize all the stop codons?
True