Transmission of Genetic Information Flashcards
1
Q
What is the Central Dogma?
The 2 strands of DNA?
When does protein synthesis occur in the cell cycle?
A
- Process of DNA to Protein
- • Sense strand; same sequence as the mRNA
• Antisense strand; opposite strand used to form mRNA - Interphase (so everything except mitosis and cytokenesis)
2
Q
Transcription:
What’s the 1st stage? Function?
What’s the 2nd stage? Function?
Enzyme used in stage 2?
What’s the 3rd stage?
A
- Capping at 5’ end with methyl-guanosine residue; Protects 5’ end from degradation, Helps move it into cytoplasm, Enchances translation
- Polyadenylated at 3’ end with 50-250 A’s; Protects 3’ end from degradation
- Polyadenylation Polymerase
- Splicing to remove introns and join exons together to form Mature mRNA
o Spliceosomes cleave strand at 5’ end of intron, which then attaches to the branching site on the strand
o 3’ end of the intron is then cleaved, and the remaining exons are joined together
3
Q
Features of RNA?
What does Translation need to occur?
A
- Degenerate, Open Reading Frame (same sequence can be used differently)
- tRNA, Initiation factors, Elongation factors
4
Q
Translation:
What’s the 1st stage?
What’s the 2nd stage?
What’s the 3rd stage?
What’s the 4thstage?
What’s the 5th stage?
What’s the 6th stage?
A
- Initiator tRNA binds to start codon using an anticodon; this tRNA carries a Methionine AA, so is the start of every protein
- Once it binds, large subunit of the ribosome binds
- The 1st tRNA begins in the P (Peptidyl site) and the next tRNA enters the A site; AA in P site breaks off from its tRNA and
attaches to the AA in the A site - Translocation; mRNA is moved along by Elongation factors to shift the tRNA molecules along, therefore leaving the A site empty once again
- mRNA moved along again to remove the tRNA from the E site and ribosome entirely
- Termination; Release factor binds to stop codon and breaks the bond between the P site tRNA and protein
