Exam 4 TA Made Study Guide Questions -Answer Key (1)
PP1- Chromosomes-chromatin-telomeres
•
DNA Density: The condensed state of DNA is the result of interaction with? How do
these interactions contribute to the folding of DNA?
Condensed state of DNA is the result of interactions with basic proteins because the
phosphodiester backbone is so negatively charged. Usually DNA is rigid and highly negatively
charged. It can’t fold upon itself b/c it repels, so wrap it with + charge using basic proteins
•
Which of the following has the highest density? Eukaryotes, Phages, or Bacteria.
What are their densities?
Phage T4 has highest density with 500 mg/mL; Eukaryotes 100 mg/mL; Bacteria 10mg/mL
•
The packaging ratio of the smallest human chromosome is 7,000. Interphase chromatin
has a packing ratio of 1,000-2,000. During mitosis, the packing ratio is 5,000-10,000.
Why the change between interphase and mitosis?
Interphase has the cell still expressing gene so not packed tightly while mitosis is forming
chromosomes which are tightly packed with higher packing ratio
•
What occurs when you add packaging (capsid) proteins to a headshell?
The more capsid proteins you add, it naturally begins to coil, condense, and package the
,DNA
•
Bacterial domains are ~80% DNA. Eukaryotic chromosome are ~50% DNA
•
A single bp mutation in CDE-III (CCG) is disruptive, it disrupts proper segregation of
sister chromatids. The subunit CDE-III is very sensitive to mutations.
Loops andloops Direction of
transcription is:
1. ???????? Transcription is going in
a counter-clockwise
direction from bottom of
picture to top.
2. ??????? Type of chromosome?
? Lampbrush Chromosome
1. Condensin II
, 2. Condensin I
Role of protein 1: Condensin II generates the
loops, is the base of the loops and forms
helical scaffold.
Role of protein 2: Condensin I is located in
the scaffold and creates the nested
scaffold (loops within the loops
A. What is this molecule? A Histone
H3 variant called CenH3
B. Octamer/Tetramer: What is H3 and
B what is the molecule described in A
A Alternating pattern of H3 octamer and
CenH3 tetramer
C. What is this? CenH3 nucleosomes
D. What is this? Kinetochore
E. What is this? Spindle microtubules
C
F. What is the importance of this
D configuration? The CenH3 tetramers recruit
proteins that form the kinetochore. The
location of the CenH3 tetramers seems to
E
PP1- Chromosomes-chromatin-telomeres
•
DNA Density: The condensed state of DNA is the result of interaction with? How do
these interactions contribute to the folding of DNA?
Condensed state of DNA is the result of interactions with basic proteins because the
phosphodiester backbone is so negatively charged. Usually DNA is rigid and highly negatively
charged. It can’t fold upon itself b/c it repels, so wrap it with + charge using basic proteins
•
Which of the following has the highest density? Eukaryotes, Phages, or Bacteria.
What are their densities?
Phage T4 has highest density with 500 mg/mL; Eukaryotes 100 mg/mL; Bacteria 10mg/mL
•
The packaging ratio of the smallest human chromosome is 7,000. Interphase chromatin
has a packing ratio of 1,000-2,000. During mitosis, the packing ratio is 5,000-10,000.
Why the change between interphase and mitosis?
Interphase has the cell still expressing gene so not packed tightly while mitosis is forming
chromosomes which are tightly packed with higher packing ratio
•
What occurs when you add packaging (capsid) proteins to a headshell?
The more capsid proteins you add, it naturally begins to coil, condense, and package the
,DNA
•
Bacterial domains are ~80% DNA. Eukaryotic chromosome are ~50% DNA
•
A single bp mutation in CDE-III (CCG) is disruptive, it disrupts proper segregation of
sister chromatids. The subunit CDE-III is very sensitive to mutations.
Loops andloops Direction of
transcription is:
1. ???????? Transcription is going in
a counter-clockwise
direction from bottom of
picture to top.
2. ??????? Type of chromosome?
? Lampbrush Chromosome
1. Condensin II
, 2. Condensin I
Role of protein 1: Condensin II generates the
loops, is the base of the loops and forms
helical scaffold.
Role of protein 2: Condensin I is located in
the scaffold and creates the nested
scaffold (loops within the loops
A. What is this molecule? A Histone
H3 variant called CenH3
B. Octamer/Tetramer: What is H3 and
B what is the molecule described in A
A Alternating pattern of H3 octamer and
CenH3 tetramer
C. What is this? CenH3 nucleosomes
D. What is this? Kinetochore
E. What is this? Spindle microtubules
C
F. What is the importance of this
D configuration? The CenH3 tetramers recruit
proteins that form the kinetochore. The
location of the CenH3 tetramers seems to
E
