BCH 5413 Exam QUESTIONS WITH
|\ |\ |\ |\ |\
ANSWERS
The number of bases per turn of DNA is___________
|\ |\ |\ |\ |\ |\ |\ |\
~10.5
What does the Meselson and Stahl experiment confirm?
|\ |\ |\ |\ |\ |\ |\
DNA replication is semi-conservative
|\ |\ |\
Heavy and light strands with nitrogen isotopes prove
|\ |\ |\ |\ |\ |\ |\
True or False|\ |\
a. Most biological DNA is positively supercoiled.
|\ |\ |\ |\ |\ |\
b. Triplex DNA is pyrimidine rich
|\ |\ |\ |\ |\
c. Chargaff's rule: A=G & T=C
|\ |\ |\ |\ |\
d. A single zinc finger can recognize 10bp of DNA
|\ |\ |\ |\ |\ |\ |\ |\ |\
A. False, negatively = Left-handed. Some is right handed =
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
positive
B. True
|\
C. False A=T C=G
|\ |\ |\
D. False, 3 bp, use multiple zinc fingers in a row for more
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
sequence specificity/bp |\
,DNA is not a uniform structure, many localized variants
|\ |\ |\ |\ |\ |\ |\ |\
can substitute protein domains, alpha helix/beta hairpin, in zinc
|\ |\ |\ |\ |\ |\ |\ |\ |\
fingers to make hybrids with different binding specificities
|\ |\ |\ |\ |\ |\ |\ |\
(designated by alpha helix) for major grooves of DNA |\ |\ |\ |\ |\ |\ |\ |\
x-ray crystallography allows us to view and design custom
|\ |\ |\ |\ |\ |\ |\ |\ |\
designer DNA-binding proteins = alter gene fxn in intact cells
|\ |\ |\ |\ |\ |\ |\ |\ |\
In A & Z DNA:
|\ |\ |\ |\
a. Which is right handed helix?
|\ |\ |\ |\ |\
b. Which one has 12bp per helical turn?
|\ |\ |\ |\ |\ |\ |\
c. Which is the dehydrated form?
|\ |\ |\ |\ |\
a. A
|\
b. Z
|\
c. A
|\
primary DNA is B |\ |\ |\
Gel electrophoresis
|\
molecular separation technique |\ |\
,can separate nucleic acids or proteins
|\ |\ |\ |\ |\
make AGAROSE gel with slots
|\ |\ |\ |\
hot liquid poured with "teeth"
|\ |\ |\ |\
put DNA in slot, run electric current at neutral pH
|\ |\ |\ |\ |\ |\ |\ |\ |\
DNA = negatively charged (phosphates) = migrates towards
|\ |\ |\ |\ |\ |\ |\ |\
positive end |\
key is friction
|\ |\
DNA stained with fluorescent dye, looked at under UV
|\ |\ |\ |\ |\ |\ |\ |\
unknown DNA electrophoresed parallel with known to determine
|\ |\ |\ |\ |\ |\ |\ |\
size
distance migrated = can plot on graph with log of molecular
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
weights or number of bp |\ |\ |\ |\
ex: 20mm = 910bp
|\ |\ |\
PFGE = Pulsed Field Gel Electrophoresis
|\ |\ |\ |\ |\
for longer sequences
|\ |\
, as large as some chromosomes in yeast
|\ |\ |\ |\ |\ |\
What is PAGE? |\ |\
Polyacrylamide Gel Electrophoresis |\ |\
used for PROTEINS |\ |\
have to denature the protein = treat with detergent, SDS, sodium
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
dodecyl sulfate
|\ |\
SDS-PAGE
SDS advantages:|\
1) coats polypeptides with (-) charge
|\ |\ |\ |\ |\
2) masks natural charge so results are purely based on molecular
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
weight
|\
What is 2-D gel electrophoresis?
|\ |\ |\ |\
LESS POWER: use two different pH values to compare, pH affects
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
net charge so different rates of mobility
|\ |\ |\ |\ |\ |\
|\ |\ |\ |\ |\
ANSWERS
The number of bases per turn of DNA is___________
|\ |\ |\ |\ |\ |\ |\ |\
~10.5
What does the Meselson and Stahl experiment confirm?
|\ |\ |\ |\ |\ |\ |\
DNA replication is semi-conservative
|\ |\ |\
Heavy and light strands with nitrogen isotopes prove
|\ |\ |\ |\ |\ |\ |\
True or False|\ |\
a. Most biological DNA is positively supercoiled.
|\ |\ |\ |\ |\ |\
b. Triplex DNA is pyrimidine rich
|\ |\ |\ |\ |\
c. Chargaff's rule: A=G & T=C
|\ |\ |\ |\ |\
d. A single zinc finger can recognize 10bp of DNA
|\ |\ |\ |\ |\ |\ |\ |\ |\
A. False, negatively = Left-handed. Some is right handed =
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
positive
B. True
|\
C. False A=T C=G
|\ |\ |\
D. False, 3 bp, use multiple zinc fingers in a row for more
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
sequence specificity/bp |\
,DNA is not a uniform structure, many localized variants
|\ |\ |\ |\ |\ |\ |\ |\
can substitute protein domains, alpha helix/beta hairpin, in zinc
|\ |\ |\ |\ |\ |\ |\ |\ |\
fingers to make hybrids with different binding specificities
|\ |\ |\ |\ |\ |\ |\ |\
(designated by alpha helix) for major grooves of DNA |\ |\ |\ |\ |\ |\ |\ |\
x-ray crystallography allows us to view and design custom
|\ |\ |\ |\ |\ |\ |\ |\ |\
designer DNA-binding proteins = alter gene fxn in intact cells
|\ |\ |\ |\ |\ |\ |\ |\ |\
In A & Z DNA:
|\ |\ |\ |\
a. Which is right handed helix?
|\ |\ |\ |\ |\
b. Which one has 12bp per helical turn?
|\ |\ |\ |\ |\ |\ |\
c. Which is the dehydrated form?
|\ |\ |\ |\ |\
a. A
|\
b. Z
|\
c. A
|\
primary DNA is B |\ |\ |\
Gel electrophoresis
|\
molecular separation technique |\ |\
,can separate nucleic acids or proteins
|\ |\ |\ |\ |\
make AGAROSE gel with slots
|\ |\ |\ |\
hot liquid poured with "teeth"
|\ |\ |\ |\
put DNA in slot, run electric current at neutral pH
|\ |\ |\ |\ |\ |\ |\ |\ |\
DNA = negatively charged (phosphates) = migrates towards
|\ |\ |\ |\ |\ |\ |\ |\
positive end |\
key is friction
|\ |\
DNA stained with fluorescent dye, looked at under UV
|\ |\ |\ |\ |\ |\ |\ |\
unknown DNA electrophoresed parallel with known to determine
|\ |\ |\ |\ |\ |\ |\ |\
size
distance migrated = can plot on graph with log of molecular
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
weights or number of bp |\ |\ |\ |\
ex: 20mm = 910bp
|\ |\ |\
PFGE = Pulsed Field Gel Electrophoresis
|\ |\ |\ |\ |\
for longer sequences
|\ |\
, as large as some chromosomes in yeast
|\ |\ |\ |\ |\ |\
What is PAGE? |\ |\
Polyacrylamide Gel Electrophoresis |\ |\
used for PROTEINS |\ |\
have to denature the protein = treat with detergent, SDS, sodium
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
dodecyl sulfate
|\ |\
SDS-PAGE
SDS advantages:|\
1) coats polypeptides with (-) charge
|\ |\ |\ |\ |\
2) masks natural charge so results are purely based on molecular
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\
weight
|\
What is 2-D gel electrophoresis?
|\ |\ |\ |\
LESS POWER: use two different pH values to compare, pH affects
|\ |\ |\ |\ |\ |\ |\ |\ |\ |\ |\
net charge so different rates of mobility
|\ |\ |\ |\ |\ |\
