Molecular Flashcards
DNA Ligase
-binds together Okazaki fragments on lagging strands
Leading cause of community acquired pneumonia, otitis media, and meningitis in adults
-strep pneumo
Type 1 Collagen
- dermis (skin), bone, tendons, ligaments, blood vessels, scar tissue
- dz: osteogenesis imperfecta
Type 2 Collagen
-cartilage, vitreous humor, nucleus pulposis
Type 3 Collagen
- skin, lungs, intestines, blood vessels (reticulin), bone marrow
- dz: vascular type of Ehlers-Danlos syndrome
Type 4 Collagen
-basement membranes
-alport syndrome (characterized by kidney disease, hearing loss, and eye abnormalities)
Defective in Alport Syndrome
Collagen Facts
Be So Totally Cool, Read Books Type 1: bones, skin, tendon Type 2: cartilage Type 3: reticulin (vessels) Type 4: basement membrane Glycine is most common amino acid in collagen
Tryptase
- relatively specific to mast cells
- elevated tryptase is used to support clinical dx of anaphylaxis
Birbeck Granules
- tennis racket shaped cytoplasmic organelles that are only found in Langerhans cells (dendritic cell of skin and mucosa)
- function is unclear, but helpful cell marker
Zinc Finger Domain Function
- most commonly identified DNA binding domain in humans
- bound by fat soluble hormones to alter DNA expression
- ex. estrogen, aldosterone, and cortisol
What type of bond is involved in making beta pleated sheets (and all secondary structure of proteins)?
-hydrogen bonds
Heterochromatin vs Euchromatin
- heterochromatin- condensed DNA (barr body), many deacetylated histones with low level of transcription
- euchromatin- open DNA, high level of transcription activity
Myxomatous Degeneration
-pathologic deterioration of the connective tissue
Ehler’s Danlos
- hypermobile joints, overelastic skin
- collagen synthesis disorder
- common mutations: lysyl hydroxylase and procollagen peptidase enzymes responsible for collagen synthesis
- results in impaired cleavage of terminal propeptidases in the extracellular space
Fibrillin-1 Mutation
- major component of microfibrils that form sheath around elastin
- defects cause Marfan syndrome
Enhancer/Silencer Location
- may be located upstream, downstream, or within a transcribed gene
- fxn to inc. or dec. the rate of transcription
Location of Promotor Region
-typically located 25 or 75 bases upstream from their associated genes and fxn to initiate transcription
Collagen Stucture
- triple helix
- Gly-x-y amino acid sequence
- 3 polypeptide a-chains held together by hydrogen bonds
What molecules are involved in cell adhesion?
Integrin binds to fibronectin, collagen, and laminin.
What molecules are involved in cell adhesion?
Integrin binds to fibronectin, collagen, and laminin.
SnRNPs
Small nuclear ribonucleoproteins
A collections of snRNPs forms a splicosome that helps remove introns from premRNA.
Spinal muscular atrophy is a dz characterized by mutation in SMN1 gene that causes dec. snRNPs and leads to hypotonia in infants.
PPARgamma
Peroxisome proliferator activated receptor gamma is an intracellular nuclear receptor that is activated by glitizone drugs to inc. sensitivity to insulin.
Located in nucleus.
JAK/STAT Pathway
- cell surface receptor pathway that leads to changes in gene transcription
- things that activate this pathway include the “tins” and “ters” (ie. prolactin, EPO, thrombopoeitin, leptin, interferons, interleukin) and GH
Nuclear fragments and pyknosis are part of what cell process?
Apoptosis
Baroreceptors
- stretch receptors
- inc. firing rate in response to stretch
C Reactive Protein
- released from liver
- marker of any inflammation
- acute phase protein
- inc. in response to IL-6
- activates complement and promotes phagocytosis of macrophages
AATAAA
-polyadenylation signal sequene
APO B
- binds LDL receptor
- may be dec. in familial hypercholesterolemia
- involved in non-HDL metabolism
- apoB100 is hepatic lineage
- apoB48 is intestinal lineage
APOA1
- HDL protein
- part of reverse cholesterol transport
- activates LCAT
Intrinsic Endothelial Vasodilators
- nitric oxide
- prostacyclin
- these also prevent platelet binding in healthy endothelium
Intrinsic Endothelial Vasoconstrictor
- endothelin
- thromboxane A2
Karyorrhexis
-fragmentation of pyknotic (condensed) nuclei during apoptosis
KRAS
- regulation requires balance between GTP and GDP
- active when bound to GTP
- RAS gene mutations are implicated in tumor development
Creatinine Kinase
- CK
- measure of muscle damage
- inc. with MI or muscle damage after strenuous exercise
Rb
- regulates G1 to S phase of cell cycle
- proliferation signals activate cyclin dependent kinase 4
- CDK4 phosphorylates Rb protein (CDK4 is inhibited by high levels of p27)
- hyperphsophorylated Rb is inactive and allows transition to S phase
