Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
34 Cards in this Set
- Front
- Back
What is heterochromatin?
|
DNA that's condensed tightly.
Transcriptionally inactive. |
|
What is euchromatin?
|
loosely condensed DNA
genes can be transcribed |
|
In what direction is DNA/RNA synthesized?
|
The 5' end of the incoming nucleotide (has the triphosphate used to make the bond) binds to the 3' end of the elongating chain.
|
|
How is mRNA read?
|
It is READ in the 5' to 3' direction.
|
|
In protein synthesis, which end of the incoming amino acid adds to which end of the growing chain?
|
The N-part of the incoming AA adds to the C-part of the elongating chain.
|
|
What is the mRNA start codon?
|
AUG
|
|
What are the stop codons for mRNA
|
UGA, UAA, UAG
|
|
What does RNA pol-I do?
|
Makes ribosomal RNA (rRNA) for eukaryotes
|
|
What does RNA pol-II do?
|
Makes mRNA for eukaryotes
|
|
What does RNA pol-III do?
|
Makes tRNA for eukaryotes
|
|
How does the Golgi 'tag' proteins for distribution to the lysosome?
|
It adds mannose-6-phosphate, which 'packages' protein for delivery to lysosome.
|
|
What is clathrin?
|
Protein that directs vesicles to be sent to specific places.
If from Golgi → lysosome. If from plasma membrane → endosomes (means of receptor mediated endocytosis). |
|
Discuss structure of microtubules
|
Made of 9 + 2 polymerized alpha & beta tubulin dimers.
|
|
Dynein & Kinesin
|
Dynein: transports stuff retrograde on microtubule.
Kinesin: transports stuff forward on microtubule |
|
What is the defect assoc. with Chediak-Higashi syndrome?
|
microtubule polymerization defect
|
|
Type-I collagen
|
found in bone, skin, and tissue
|
|
type-II collagen
|
found in cartilage
|
|
type-III cartilage uses
|
skin, blood vessels, uterous, granulation tissue
defective in Ehlers-Danlos |
|
type-IV cartilage use
|
*IMPORTANT
found in basement membrane of tissue Defective in Alport's syndrome |
|
How is collagen processed?
|
In the fibroblast, it is synthesized in the RER, then hydroxylated (req. vitamin C) & glycosylated in the ER, before it's exocytosed as procollagen
Outside the fibroblast, it's proteolytically cleaved into tropocollagen before X-linked into collagen fibrils |
|
Elasting: discuss it
|
stretchy; found in lungs, large arteries, leastic ligaments, etc
lots of Pro and Gly broken down by elastase, which is inhibited by alpha1-antitrypsin Defective in Marfan's syndrome |
|
What is Southern blot?
|
DNA tagged with labeled DNA
|
|
what is Northern blot
|
RNA tagged with labeled DNA
|
|
Western Blot
|
Protein separated by gel electrophoresis and tagged with radioactive Ab
|
|
How does ELISA work?
|
Patients serum is mixed with labeled agent (to determine if pt has Ab against it) or with labeled Ab (to see if antigen is present)
|
|
What is imprinting?
|
At a single gene locus, only one allele is active.
If the active gene is deleted or mutated, this can lead to a disease state. |
|
Bohr effect
|
Deoxygenated hemoglobin accepts protons more readily than oxygenated Hg
This means that when pH is lower (i.e. increased [lactic acid] from excessive glycolysis due to exertion), the oxygen will pop off of Hg more readily. |
|
2,3 bisphosphglycerate
|
Made from an intermediate of glycolysis
2,3-BPG decreases O2 affinity to Hg (induces oxygen to come off) 2,3 BPG shifts the O2 saturation curve (relative to partial pressure of oxygen) to the right Interesting note: 2,3 BPG levels are higher in people who live at higher altitudes; likely require more oxygen to come off the RBC relative to the partial pressure |
|
Sickle Cell Anemia mutation
|
Missense mutation (Glu --> Val) at AA position 6 of beta-chain
At low oxygen saturation, HbS proteins polymerize and 'sickle' inside RBC |
|
methemoglobinemia
|
Ferrous heme (Fe2+) converts to Ferric heme (Fe3+) & loses ability to bind O2
can be from drugs or inherited conditions |
|
beta-thalassemias
|
synthesis of beta-chain decreased or gone
excess alpha-chains form precipitate, which eventually kill the RBC HbF and HbBart's build up in the system Tx - regular transfusions, which can eventually lead to hemosiderosis |
|
alpha-thalassemias
|
4 alpha genes; severity increases with number of mutations
(silent carrier, alpha-thalassemia trait, HgH, death) |
|
hydroxyproline
|
post-translational modification found in collagen
important in stabilizing triple helix structure of collagen by minimizing H-bond formation |
|
The 3 amino acids important to collagen formation
|
glycine - allows for tight helix wrapping
hydroxyproline - provides stabilization by minimizing H-bond formation hydroxylysine - stabilize molecular structure; allow for carbohydrate attachment |