cellular + a sprinkle of lab techniques

Question 1

CDKs?

Answer 1

cell cycle regulators

constitutive and inactive

Question 2

cyclins?

Answer 2

cell cycle regulators

phase specific, activate CDKs - form complexes

Question 3

cyclin-CDK complexes?

Answer 3

phosphorylate proteins –> cell cycle progression/coordination

Question 4

tumor suppressor function?

Answer 4

p53, Rb - prevent progression from G1 to S

Question 5

which cells are “permanent” (remain in G0)?

Answer 5

neurons, mm, RBCs - regenerate from stem cells

Question 6

which cells are “stable/quiescent” (enter G1 when stimulated)?

Answer 6

hepatocytes

lymphocytes

Question 7

which cells are “labile” (no G0, divide rapidly)?

Answer 7

bone marrow, gut epithelium, skin, hair follicles, germ cells

Question 8

what happens in the RER?

Answer 8

synthesis of proteins and post-translational modification

free ribosomes –> cystosolic and organellar proteins

Question 9

what’s a Nissl body?

Answer 9

RER of neurons - makes peptide neurotransmitters

Question 10

which types of cells have a sh*t-ton of RER?

Answer 10

mucus-secreting goblet cells in SI

Ab-secreting plasma cells

Question 11

what happens in the SER?

Answer 11

steroid synthesis
detox (CYP450)

No surface ribosomes

Question 12

which types of cells have a sh*t-ton of SER?

Answer 12

liver hepatocytes

steroid-hormone producing cells (adrenal cortex and gonads)

Question 13

what happens in the nucleolus?

Answer 13

rRNA transcription

processing of ribosome assembly

Question 14

what happens in the Golgi?

Answer 14

protein/lipid distribution
asparagine N-oligosaccharide modification
ser/thr O-oligosaccharide addition
mannose-6-P added to proteins –> lysosome trafficking

Question 15

what’s an endosome?

Answer 15

sorts material from outside cell or from Golgi

sends to lysosomes, membrane, or Golgi

Question 16

coarse facial features, clouded corneas, restricted joint movement, high plasma levels of lysosomal enzymes?

Answer 16

inclusion cell disease
defect in N-acetylglucosaminyl-1-phosphotransferase
Golgi can’t add mannose6P to protein –> extracellular instead of lysosomal secretion

Question 17

what is a signal recognition particle?

Answer 17

cytosolic ribonucleoprotein
traffics proteins from ribosome to RER

** if absent: accumulation of proteins in cytosol

Question 18

what does COPI do?

Answer 18

mediates retrograde trafficking in Golgi and from cis-Golgi to ER

Question 19

what does COPII do?

Answer 19

mediates anterograde trafficking from ER to cis-Golgi

Question 20

what does clathrin do?

Answer 20

mediates:
trans-Golgi –> lysosomes
plasma membrane –> endosomes

Question 21

what happens in the peroxisome?

Answer 21

catabolism of VLCFAs, branched chain FAs, AAs

Question 22

what happens in the proteasome?

Answer 22

degradation of damaged or ubiquitinated proteins

** defects implicated in Parkinson’s

Question 23

what do microfilaments do?

Answer 23

muscle contraction

cytokinesis

Question 24

what do intermediate filaments do?

Answer 24

maintain cell structure

Question 25

what do microtubules do?

Answer 25

movement | cell division

Question 26

what does vimentin stain for?

Answer 26

connective tissue?

Question 27

what does desmin stain for?

Answer 27

muscle (desMin)

Question 28

what does cytokeratin stain for?

Answer 28

epithelial cells

Question 29

what does GFAP stain for?

Answer 29

neuroglia

Question 30

what is the structure of a microtubule?

Answer 30

alpha and beta tubulin heterodimers with 2 GTP bound dynein: retrograde transport kinesin: anterograde transport

Question 31

which drugs act on microtubules?

Answer 31

``` Microtubules Get Constructed Very Poorly: mebendazole griseofulvin colchicine vincristine/vinblastine paclitaxel ```

Question 32

what is the structure of cilia?

Answer 32

9+2 microtubulae doublet arrangement | axonemal dynein

Question 33

what does ouabain do?

Answer 33

binds K+ site on Na-K ATPase

Question 34

how does dig work?

Answer 34

direct inhib of Na-K ATPase --> indirect inhib of Na/Ca exchange --> increased Ca --> increased cardiac contractility

Question 35

where are the types of collagen found?

Answer 35

``` Be (So Totally) Cool, Read (Better) Books! type I: bone, skin, tendon type II: cartilage type III: reticulin, blood vessels typve IV: basement membrane, lens ```

Question 36

which dz involves type I collagen?

Answer 36

OI

Question 37

which dz involves type III collagen?

Answer 37

vascular type Ehlers Danlos

Question 38

which dz involves type IV collagen?

Answer 38

Alport | Goodpasture

Question 39

what are the steps of collagen synthesis?

Answer 39

1) synthesis in the RER: translation of preprocollagen (gly-pro-lys) 2) hydroxylation in RER: pro and lys, needs vit C 3) glycosylation in RER: hydroxylysine glycos, hydrogen and disulfide bond formation --> procollagen 4) exocytosis 5) proteolytic processing: cleavage of disulfide terminals --> tropocollagen 6) crosslinking: lys-hydroxylys (lysyl oxidase needs Cu) --> fibrils

Question 40

multiple fractures with minimal trauma, blue sclerae, hearing loss, dental imperfections?

Answer 40

OI - AD | decreased prod of otherwise normal type I collagen (problems forming procollagen)

Question 41

hyperextensible skin, easy bleeding, hypermobile joints, berry aneurysms, aortic aneurysms?

Answer 41

Ehlers Danlos - many inheritance types type V: classic, jt and skin type III: vascular and organ rupture

Question 42

brittle kinky hair, growth retardation, hypotonia?

Answer 42

Menkes - XLR defect in ATP7A --> defective Cu transport/absorption decreased activity of lysyl oxidase --> decreased collagen synthesis

Question 43

what is the structure of elastin?

Answer 43

nonhydroxylated proline, glycine, lysine tropoelastin + fibrillin scaffolding broken down by elastase (a1at inhibits elastase)

Question 44

where is elastin found?

Answer 44

``` skin lungs large aa ligaments vocal cords ligamentum flavum ```

Question 45

steps of PCR?

Answer 45

denaturation annealing elongation

Question 46

what's with all the f***ing blots?

Answer 46

SNoW DRoP: southern = DNA Northern = RNA Western = protein (sneaky sneaky: southwestern = DNA-binding proteins!) if we have to know any more than that, fuck it

Question 47

direct vs indirect ELISA?

Answer 47

direct: test Ab looks for specific antigen indirect: test Ab/Ag looks for specific Ab-Ag complex

Question 48

cre-lox system?

Answer 48

inducibly manipulates genes at specific developmental points