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BIOCH 330 Questions and Correct Answers | Latest
Update
What is the function of RNA?
Ans: - Holds information
- Structure
- Protein synthesis
T/F: the RNA transcript is complementary to template & identical to non-
Assignment Expert
template.
Ans: True.
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What are the 4 classes of RNA?
Ans: - Messenger (mRNA)
2026
- Transfer (tRNA)
- Ribosomal (rRNA)
©
- Small nuclear (snRNA)
How does RNA pol. perform proof-reading?
Ans: By inducing the reverse of the polymerization rxn at the same
active site for forward trxn.
What are the similarities b/w repl'n and trxn?
Ans: - 5'—>3' synthesis
- Proof-reading (DNA pol. is more efficient)
What are the differences b/w repl'n and trxn?
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Ans: - Repl'n: DNA template, both strands copied, primers required,
entire chr. copied, makes dsDNA & dNTPs
- Trxn: DNA/RNA template, 1 strand at a time (synthesis can occur off
either strand), no primers required, short sequences, makes ssRNA &
rNTPs
What is the mechanism of transcription by RNA pol.?
Ans: Binds ds template to form a closed complex -> pol. II's C-terminus
is phosphorylated, shifts into open complex (initiation) -> pol. complex
dissociated from factors bound to TATA box -> promoter is cleared,
Assignment Expert
elongation occurs
What is RNA pol. footprinting?
Guru01 - Stuvia
Ans: As RNAse is applied to the trxn products, it will not cut them at the
RNA pol. complex binding areas (closed complex). When run on a gel,
there'll be a certain section of RNA sequence elements missing (footprint)
2026
in the region of the gel (promoter region).
©
How many classes of RNA pol. are there and what are their products?
Ans: - Pol I: rRNA
- Pol II: mRNA.
- Pol III: ss rRNA, tRNA
What is the role of RNA pol. II?
Ans: Recognizes promoter sequence TATAAA (TATA box) and the Inr
sequence. Involves factors like TBP (TATA-binding protein), TFIIH
(helicase, unwinds DNA at promoter, phosphorylates Pol. II within the
CTD, recruits ntd-excision repair proteins), and TFIID (TBP & TBP-
associated factors (TAFS); modulate trxn complex assembly at different
promoters).
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What is the Central Dogma and what are its amendments/elaborations?
Ans: DNA —> RNA —> Protein
- RNA has other functions like catalysis (splicing, peptidyltransferase,
RNase P), structure (ribosome, tRNAs), or interference (miRNAs).
- RNA may be the final product (tRNA, rRNA, snRNA, miRNA).
- RNA is modified before becoming a protein w/ the 5' cap,
polyadenylylation, splicing, & editing.
- Reverse trxn: RNA->DNA in retroviruses, retrotransposons, &
Assignment Expert
telomerase.
Guru01 - Stuvia
- RNA-dependent RNA polymerization can occur in some viruses.
What is the promoter region composed of?
Ans: Polymerase binding site & adjacent regulatory elements.
2026
- ex: TATAAA (TATA box).
©
What is Reverse Transcriptase (RT) and what inhibits it?
Ans: Synthesizing DNA using an RNA template. Has a sigma subunit
(specific promoters to the trxn region, cleared by RNA pol., determine the
specificity of prokaryotic RNA pol. for distinct promoters).
- AZT: chain terminator, inhibits DNA synthesis by RT. It is a substrate
for endogenous peroxidases.
What is the mechanism of rho-dependent termination?
Ans: RNA pol. stalls as the product forms -> rho (helicase) is recruited
upstream to the RNA trxn bubble (A-U rich) -> isomerizes (intra-strand
hybridization) -> NUSA binds the DNA-RNA complex -> knocks off RNA
pol. to terminate the trxn
BIOCH 330 Questions and Correct Answers | Latest
Update
What is the function of RNA?
Ans: - Holds information
- Structure
- Protein synthesis
T/F: the RNA transcript is complementary to template & identical to non-
Assignment Expert
template.
Ans: True.
Guru01 - Stuvia
What are the 4 classes of RNA?
Ans: - Messenger (mRNA)
2026
- Transfer (tRNA)
- Ribosomal (rRNA)
©
- Small nuclear (snRNA)
How does RNA pol. perform proof-reading?
Ans: By inducing the reverse of the polymerization rxn at the same
active site for forward trxn.
What are the similarities b/w repl'n and trxn?
Ans: - 5'—>3' synthesis
- Proof-reading (DNA pol. is more efficient)
What are the differences b/w repl'n and trxn?
, 2 for specific request mail
Ans: - Repl'n: DNA template, both strands copied, primers required,
entire chr. copied, makes dsDNA & dNTPs
- Trxn: DNA/RNA template, 1 strand at a time (synthesis can occur off
either strand), no primers required, short sequences, makes ssRNA &
rNTPs
What is the mechanism of transcription by RNA pol.?
Ans: Binds ds template to form a closed complex -> pol. II's C-terminus
is phosphorylated, shifts into open complex (initiation) -> pol. complex
dissociated from factors bound to TATA box -> promoter is cleared,
Assignment Expert
elongation occurs
What is RNA pol. footprinting?
Guru01 - Stuvia
Ans: As RNAse is applied to the trxn products, it will not cut them at the
RNA pol. complex binding areas (closed complex). When run on a gel,
there'll be a certain section of RNA sequence elements missing (footprint)
2026
in the region of the gel (promoter region).
©
How many classes of RNA pol. are there and what are their products?
Ans: - Pol I: rRNA
- Pol II: mRNA.
- Pol III: ss rRNA, tRNA
What is the role of RNA pol. II?
Ans: Recognizes promoter sequence TATAAA (TATA box) and the Inr
sequence. Involves factors like TBP (TATA-binding protein), TFIIH
(helicase, unwinds DNA at promoter, phosphorylates Pol. II within the
CTD, recruits ntd-excision repair proteins), and TFIID (TBP & TBP-
associated factors (TAFS); modulate trxn complex assembly at different
promoters).
, 3 for specific request mail
What is the Central Dogma and what are its amendments/elaborations?
Ans: DNA —> RNA —> Protein
- RNA has other functions like catalysis (splicing, peptidyltransferase,
RNase P), structure (ribosome, tRNAs), or interference (miRNAs).
- RNA may be the final product (tRNA, rRNA, snRNA, miRNA).
- RNA is modified before becoming a protein w/ the 5' cap,
polyadenylylation, splicing, & editing.
- Reverse trxn: RNA->DNA in retroviruses, retrotransposons, &
Assignment Expert
telomerase.
Guru01 - Stuvia
- RNA-dependent RNA polymerization can occur in some viruses.
What is the promoter region composed of?
Ans: Polymerase binding site & adjacent regulatory elements.
2026
- ex: TATAAA (TATA box).
©
What is Reverse Transcriptase (RT) and what inhibits it?
Ans: Synthesizing DNA using an RNA template. Has a sigma subunit
(specific promoters to the trxn region, cleared by RNA pol., determine the
specificity of prokaryotic RNA pol. for distinct promoters).
- AZT: chain terminator, inhibits DNA synthesis by RT. It is a substrate
for endogenous peroxidases.
What is the mechanism of rho-dependent termination?
Ans: RNA pol. stalls as the product forms -> rho (helicase) is recruited
upstream to the RNA trxn bubble (A-U rich) -> isomerizes (intra-strand
hybridization) -> NUSA binds the DNA-RNA complex -> knocks off RNA
pol. to terminate the trxn
