Bio 200 EXAM QUESTIONS WITH COMPLETE
SOLUTIONS!!/GRADE A+ GUARANTEED
SATISFACTION
Packed chromosomes separate into daughter cells in... - ANSWER-anaphase
M phase - ANSWER-Anaphase, prophase, metaphase and telophase:
S phase - ANSWER-DNA replication
DNA polymerase III, helicase, topoisomerase and the sliding clamp are active
cyclin - ANSWER-proteins that are typified by their concentrations rhythmically change throughout cell
cycles
cyclin dependent Kinase - ANSWER-only active when bound to cyclin, (part of MPF) initiates M phase,
catalyzes phosphorylation of other proteins to start M phase
phosphorylation of one site of Cdk activates it, the second site inhibits it. Both sites phosphorylated
after cyclin binds. Concentrations of dimer can change without inducing M phase.
late in G2 an enzyme removes the inhibitory phosphate and turns on Cdk
during anaphase an enzyme degrades MPF's cyclin. MPF is turned off by a product of mitosis, or is
tagged by ubiquitin and destroyed by the proteasome
MPF - ANSWER-bound combination of two proteins
chaperone proteins - ANSWER-assist protein folding
ubiquitin ligase - ANSWER-adds ubiqu tags
,microRNA - ANSWER-base pairs to RNA that is being held in the RISC complex, single miRNA can regulate
may different mRNAs, single mRNA can be regualted by many different miRNAs
no start or stop codons, very short sequence, very hard to find/study, wraps into hairpins, mature
miRNA is 2 single strands
possible uses:
Need to fight infection by viruses with DNA genomes
Need to fight infection by viruses with RNA genomes
Need to decrease overall levels of a particular protein
Need to decrease overall levels of a particular mRNA
Need to increase phosphorylation of a particular protein
not good use:
Need to remove any mRNAs with random mutations
RISC complex - ANSWER-*golbal regulation, decreases all translation, translation is energy intensive
holds and cuts specific RNA
decreases gene expression
defense against foreign RNA
miRNA completmentary to target RNA (about 20 base pairs long)
RNA interference: miRNA matches tageret mRNA and holds it for destruction if perfect match, and
blocks translation if not perfect match
, 1) RNA pol transcribes genes coding for RNAs that form hair pins
2)single stranded 5' and 3' ends trimmed off of hair pin
3)miRNA transported to cytoplasm, trim off loop
4) double stranded miRNA unwound by helicase
5) one strand degraded, other strand to RISC
6) miRNA binds to completmentary mRNA
7) perfect match=cutting, close match= blocking translation
post-translational modifications - ANSWER-*changes the protein after its made*
Ubiquitination (targeted for destruction)
Phosphates (Addition: kinase, Removal: phosphorylase)
Acetylation (add or subtract acetyl groups)
Addition of carbohydrates (not amino acids)
Cleavage by proteases (not reversible)
*very fase, not efficient*
increasing RNA 1/2 life - ANSWER--5' cap (protects the 5' end of the strand of mRNA)
-poly A tail (protects the 3' end by adding a long sequence of only A's, not coded for, post
transcriptional)
gene expression in eukaryotes vs. prokaryotes - ANSWER-DNA packing: default of eukaryotes=off,
prokaryotes=on, negative control that doesn't exist in prokaryotes
SOLUTIONS!!/GRADE A+ GUARANTEED
SATISFACTION
Packed chromosomes separate into daughter cells in... - ANSWER-anaphase
M phase - ANSWER-Anaphase, prophase, metaphase and telophase:
S phase - ANSWER-DNA replication
DNA polymerase III, helicase, topoisomerase and the sliding clamp are active
cyclin - ANSWER-proteins that are typified by their concentrations rhythmically change throughout cell
cycles
cyclin dependent Kinase - ANSWER-only active when bound to cyclin, (part of MPF) initiates M phase,
catalyzes phosphorylation of other proteins to start M phase
phosphorylation of one site of Cdk activates it, the second site inhibits it. Both sites phosphorylated
after cyclin binds. Concentrations of dimer can change without inducing M phase.
late in G2 an enzyme removes the inhibitory phosphate and turns on Cdk
during anaphase an enzyme degrades MPF's cyclin. MPF is turned off by a product of mitosis, or is
tagged by ubiquitin and destroyed by the proteasome
MPF - ANSWER-bound combination of two proteins
chaperone proteins - ANSWER-assist protein folding
ubiquitin ligase - ANSWER-adds ubiqu tags
,microRNA - ANSWER-base pairs to RNA that is being held in the RISC complex, single miRNA can regulate
may different mRNAs, single mRNA can be regualted by many different miRNAs
no start or stop codons, very short sequence, very hard to find/study, wraps into hairpins, mature
miRNA is 2 single strands
possible uses:
Need to fight infection by viruses with DNA genomes
Need to fight infection by viruses with RNA genomes
Need to decrease overall levels of a particular protein
Need to decrease overall levels of a particular mRNA
Need to increase phosphorylation of a particular protein
not good use:
Need to remove any mRNAs with random mutations
RISC complex - ANSWER-*golbal regulation, decreases all translation, translation is energy intensive
holds and cuts specific RNA
decreases gene expression
defense against foreign RNA
miRNA completmentary to target RNA (about 20 base pairs long)
RNA interference: miRNA matches tageret mRNA and holds it for destruction if perfect match, and
blocks translation if not perfect match
, 1) RNA pol transcribes genes coding for RNAs that form hair pins
2)single stranded 5' and 3' ends trimmed off of hair pin
3)miRNA transported to cytoplasm, trim off loop
4) double stranded miRNA unwound by helicase
5) one strand degraded, other strand to RISC
6) miRNA binds to completmentary mRNA
7) perfect match=cutting, close match= blocking translation
post-translational modifications - ANSWER-*changes the protein after its made*
Ubiquitination (targeted for destruction)
Phosphates (Addition: kinase, Removal: phosphorylase)
Acetylation (add or subtract acetyl groups)
Addition of carbohydrates (not amino acids)
Cleavage by proteases (not reversible)
*very fase, not efficient*
increasing RNA 1/2 life - ANSWER--5' cap (protects the 5' end of the strand of mRNA)
-poly A tail (protects the 3' end by adding a long sequence of only A's, not coded for, post
transcriptional)
gene expression in eukaryotes vs. prokaryotes - ANSWER-DNA packing: default of eukaryotes=off,
prokaryotes=on, negative control that doesn't exist in prokaryotes
