Nucleus Transcription and Translation Flashcards
Why does the coding strand make sense?
The coding strand makes sense: aka the sense strand, the coding strand has the same sequence as the RNA, except RNA substitutes U for T.
How is gene expression initiated and regulated?
Promoter sequences upstream from a gene recruit transcription factors, which then recruit RNA polymerase II. Distal regulatory sequences—ie, enhancers and silencers—regulate expression.
What modifications occur to transform pre-mRNA into mRNA?
RNA processing in eukaryotes involves the splicing of introns, the addition of a 5’ 7-methyguanosine cap, and the addition of a 3’-poly(A) tail.
What are the three types of RNA used during translation, and what function do they serve?
Messenger RNA is the gene transcript to be translated. Ribosomal RNA, along with associated proteins, forms the ribosome that conducts translation. Transfer RNAs carry amino acids into the ribosome, using their anticodon to ensure each amino acid is incorporated in the correct order into the growing peptide chain.
When do ATP and GTP provide energy during translation?
ATP: tRNA Activation (charging)
GTP: tRNA Gripping and Going (translocation)
What are the stop codons?
- *UAA**: U Are Away
- *UGA**: U Go Away
- *UAG**: U Are Gone
tRNAs have four functional sites:
1) they bind amino acids on their 3’ end 2) an anticodon loop matches with mRNA 3) the D-arm is used by aminoacyl-tRNA synthetase to ensure correct charging 4) and the T-arm helps the tRNA enter the ribosome.
Proteins that are destined to be secreted, retained in the RER or Golgi, trafficked to the lysosome, or bound to the plasma membrane are instead translated by ribosomes bound to the ______
Ribosomal Endoplasmic Reticulum (RER)
______ don’t have proofreading ability; they rely on the accuracy of tRNA charging
Ribosomes
A biologist has identified a new chemical from a fungus that has new antibacterial effects. Exposure of bacterial cells to the chemical interrupts DNA replication and the RNA remains as Okazaki fragments. Which of the following would most likely be inhibited by the compound?
DNA polymerase I - This is the correct answer. DNA polymerase I in bacteria contains the 5’-3’ exonuclease that removes the primer from Okazaki fragments and replaces RNA with DNA, allowing the ligase to seal the fragments. TAKEAWAY: DNA polymerase I in bacteria contains the 5’-3’ exonuclease that removes the primer from Okazaki fragments and replaces RNA with DNA, allowing the ligase to seal the fragments.
