BIO 200 EXAM 2 UPDATED ACTUAL QUESTIONS AND
CORRECT ANSWERS
Question:
1. gene expression
Answer:
process of converting stored information into molecules that actually do things in
the cell
Question:
2. central dogma of micro-biology
Answer:
DNA->RNA->protien->work
Question:
3. supercoiling
Answer:
DNA coils back on itself, coils within coils, condenses DNA to fit it into cells.
wraps around proteins called histones
must still be open enough to "read"
Question:
4. How do you get from a genotype to a phenotype?
Answer:
DNA sequence codes for mRNA which goes to tRNA which makes amino acids
which form proteins.
Question:
5. transcription
Answer:
DNA to RNA. All types of RNA made from transcription, but not all types of RNA
make proteins. polymerization of RNA monomers by RNA polymerase. RNA has
base sequence complementary to the DNA
1) NTP monomers base pair witht he DNA template
2)RNA polymerase catalyzes a reaction that cleaves off two phosphates and
forms a phosphodiester linkage between the 3' end of the growing mRNA and the
new ribonucleoside monophosphate
3) an RNA that is complementary to the gene is synthesized in the 5' to 3'
direction
,Question:
6. translation
Answer:
ribosomes attach to mRNAs and begin synthesizing proteins.
Question:
7. initation (translation)
Answer:
1) small section of rRNA in small subunit of the ribosome binds to the RBS on the
mRNA.
2) first tRNA binds to the ribosome and the start codon (near the 5' end but not
actually at the 5' end)
3) large subunit joins the complex
Question:
8. elongation (translation)
Answer:
1) E and A sites of ribosome are empty
2) tRNA binds to the A site by complmentary base pairing between the codon and
anticodon
3) A and P sites occupied, peptide bond formation begins
4) translocation: eleongation factor moves the ribosome from 5' to 3', using GTP
for energy, moves uncharged tRNA to the E site, moves tRNA holding the growing
chain to the P site, opens up the A site
**highly dynamic, ribosome is constantly changing shape
Question:
9. termination (translation)
Answer:
release factor recognizes stop codon and fills the A site. Stops are found near the
3' end but not at the very end. release factor fits tightly into the A site because it is
similar in size and shape to tRNA but it is asctually a protein.
polypeptide and uncharged tRNAs are released from the ribosome. ribosome
separates from the mRNA and its 2 subunits separate from each other.
Question:
10. ribozyme
Answer:
ribosomes are not enzymes because their active sites are entirely RNA, not
protein. They would still function if all of the protein was removed from them.
evolutionarily speaking RNA came before DNA and protein.
, Question:
11. begin translation before transcription is complete. coupling
Answer:
polyribosomes
Question:
12. RNA polymerase
Answer:
forms phosphodiester bonds between ribonucleic acid monomers.
enzyme that uses DNA to synthesize a complementary RNA molecule
does NOT need a primer to begin transcription
exergonic and spontaneous reaction since NTPs have so much potential energy in
their phosphate groups
Question:
13. Where does energy come from to polymerize RNA
Answer:
the ribonucleic acids are triphosphates, two of the three phosphates are
"chopped off" to release energy for polymerization
Question:
14. Downstream
Answer:
after where the template and RNA and attached. Direction that RNA polymerase
moves
Question:
15. upstream
Answer:
before place where template and RNA are attached. opposite direction that RNA
polymerase moves
Question:
16. what does 5' to 3' tell you?
Answer:
directionality. Only the 3' end is reactive enough to add onto
CORRECT ANSWERS
Question:
1. gene expression
Answer:
process of converting stored information into molecules that actually do things in
the cell
Question:
2. central dogma of micro-biology
Answer:
DNA->RNA->protien->work
Question:
3. supercoiling
Answer:
DNA coils back on itself, coils within coils, condenses DNA to fit it into cells.
wraps around proteins called histones
must still be open enough to "read"
Question:
4. How do you get from a genotype to a phenotype?
Answer:
DNA sequence codes for mRNA which goes to tRNA which makes amino acids
which form proteins.
Question:
5. transcription
Answer:
DNA to RNA. All types of RNA made from transcription, but not all types of RNA
make proteins. polymerization of RNA monomers by RNA polymerase. RNA has
base sequence complementary to the DNA
1) NTP monomers base pair witht he DNA template
2)RNA polymerase catalyzes a reaction that cleaves off two phosphates and
forms a phosphodiester linkage between the 3' end of the growing mRNA and the
new ribonucleoside monophosphate
3) an RNA that is complementary to the gene is synthesized in the 5' to 3'
direction
,Question:
6. translation
Answer:
ribosomes attach to mRNAs and begin synthesizing proteins.
Question:
7. initation (translation)
Answer:
1) small section of rRNA in small subunit of the ribosome binds to the RBS on the
mRNA.
2) first tRNA binds to the ribosome and the start codon (near the 5' end but not
actually at the 5' end)
3) large subunit joins the complex
Question:
8. elongation (translation)
Answer:
1) E and A sites of ribosome are empty
2) tRNA binds to the A site by complmentary base pairing between the codon and
anticodon
3) A and P sites occupied, peptide bond formation begins
4) translocation: eleongation factor moves the ribosome from 5' to 3', using GTP
for energy, moves uncharged tRNA to the E site, moves tRNA holding the growing
chain to the P site, opens up the A site
**highly dynamic, ribosome is constantly changing shape
Question:
9. termination (translation)
Answer:
release factor recognizes stop codon and fills the A site. Stops are found near the
3' end but not at the very end. release factor fits tightly into the A site because it is
similar in size and shape to tRNA but it is asctually a protein.
polypeptide and uncharged tRNAs are released from the ribosome. ribosome
separates from the mRNA and its 2 subunits separate from each other.
Question:
10. ribozyme
Answer:
ribosomes are not enzymes because their active sites are entirely RNA, not
protein. They would still function if all of the protein was removed from them.
evolutionarily speaking RNA came before DNA and protein.
, Question:
11. begin translation before transcription is complete. coupling
Answer:
polyribosomes
Question:
12. RNA polymerase
Answer:
forms phosphodiester bonds between ribonucleic acid monomers.
enzyme that uses DNA to synthesize a complementary RNA molecule
does NOT need a primer to begin transcription
exergonic and spontaneous reaction since NTPs have so much potential energy in
their phosphate groups
Question:
13. Where does energy come from to polymerize RNA
Answer:
the ribonucleic acids are triphosphates, two of the three phosphates are
"chopped off" to release energy for polymerization
Question:
14. Downstream
Answer:
after where the template and RNA and attached. Direction that RNA polymerase
moves
Question:
15. upstream
Answer:
before place where template and RNA are attached. opposite direction that RNA
polymerase moves
Question:
16. what does 5' to 3' tell you?
Answer:
directionality. Only the 3' end is reactive enough to add onto
