Term
| What is the Philadelphia Chromosome? |
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Definition
| Modified chromosome 22 (22 has a BCR). Mechanism: translocation of ABL gene to BCR site of 22. Clinical consequences: unregulated ABL resulting in acute leukemia |
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Term
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Definition
| Break control region in a chromosome. Area with a high potential to break |
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Term
| How many base pairs per turn of B-DNA? |
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Definition
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Term
| The strands of DNA are ________ |
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Definition
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Term
| What is the difference in Hydrogen bonding in nucleotides, and why is this significant? |
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Definition
A forms 2H bonds with T
and
C forms 3H bonds with G
Implications: CG rich strands will require higher temp to denature
High replication activity on AT rich regions (often ORI tend to appear there)
low activity in regions rich with CG |
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Term
| How is DNA packaged in Eukaryotic organisms? Prokaryotic? |
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Definition
Eukaryotic DNA is packaged in a nucleus
Prokaryotic DNA: no nucleus, linear or circular DNA |
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Term
| What is the distinguishing characteristic of A form DNA? |
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Definition
| 11 bp per turn as opposed to the 10 bp per turn of classic B-DNA |
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Term
| What are the characteristics of Z-form DNA? |
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Definition
-left handed helix
-rich in CG islands
-higher tendency to break |
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Term
| What is negative supercoiling? What enzyme causes it to happen? |
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Definition
Enzyme: Topoisomerase II (DNA Gyrase)
Negative supercoiling is the action of putting coils in a circular (bacterial) DNA. This serves 2 functions. 1. Storage. 2.When the DNA is unzipped by helicase positive supercoiling is less of an issue.
Clinical correlation: drugs like Cipro inhibit DNA Gyrase action and cause cell apoptosis |
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Term
[image]
Identify the structure |
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Definition
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Term
[image]
Identify the structure |
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Definition
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Term
[image]
Identify the structures |
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Definition
1. Minor Groove of DNA
2. Major Groove of DNA |
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Term
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Definition
very highly condensed and packed (like the centromere and telomere of DNA)
High Me covalent modification of histones
Tends to silence genes |
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Term
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Definition
Highly active sites for gene expression
Genes are less compressed
high Ac of histone site |
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Term
| What is the ORI? How is it different for human cells compared to bacterial cells? |
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Definition
ORI: Origin of Replication of DNA
Tend to be AT rich site on the chromosome
Humans have multiple ORI sites while Bacteria tend to have one. |
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Term
| Typical Human somatic cells contain __ pairs of chromosomes? |
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Definition
| 23 pairs, for a total of 46 chromosomes |
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Term
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Definition
| Variations from normal chromosomal count within a cell |
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Term
| Sickle Cell Anemia is caused by a point mutation of what gene? |
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Definition
HBB gene which is on chromosome 11
11p15.5 |
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Term
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Definition
| Site on chromosome for mitotic spindle attachment |
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Term
| What is the structure and function of nucleosomes? |
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Definition
Structure
octomeric core nucleosome
(H2A,H2B,H3,H4)2
H1 serves as connection between linker DNA while the nucleosome core is used to wrap DNA segments (~200 nucleotides) |
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Term
| How many nucleotides per nucleosome? |
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Definition
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Term
| What is the significance of the histone fold? |
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Definition
| The histone fold allows histones to "handshake" this makes the formation of the nucleosome core more energetically favorable |
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Term
| Nucleosome bind with DNA along the? |
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Definition
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Term
| What enzyme catalyzes Histone acetylation? |
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Definition
HAT
Histone acetlytransferase |
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Term
| What enzyme catalyzes Histone deacetylation? |
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Definition
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Term
| What enzyme catalyses Histone methylation? |
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Definition
Slides: Hmet
Histone Methylase?
Wikipedia: HMT
Histone methyltransferase |
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Term
| What enzyme catalyzes Histone demethylation? |
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Definition
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Term
| What is the function of insulator DNA? |
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Definition
| organizes coding DNA into loops for easier replication |
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Term
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Definition
Laminum are the proteins of the nucleus.
Clinical correlation: Laminopathies can cause rapid aging in children |
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