cell biology: organelles Flashcards
(38 cards)
amino acids in nuclear localization signal:
4-8 aa sequence that is part of the protein (ie histones)
recognized by nuclear pore, goes from cyto→nucleus
Proline
Arginine
Lysine
to get into “club” (NUCLEUS) need to be PALs with “bouncer”
bring POSITIVE energy (positive charged, bind to DNA)
site of steroid synthesis, detoxification of drugs + poisons
smooth ER
cells with lots of sER
hepatocytes: metabolize + detoxify drugs
adrenal cortex + gonads: steroid producing cells
site of synthesis of secretory proteins (exported) + N-linked oligosaccharide added to many proteins
rough ER
cells with lots of rER
plasma cells: secrete Abs (protein)
Nissl bodies
RER in neurons
synthesize NT to be secreted in dendrites
site of synthesis of cytosolic + organelle proteins
free ribosomes in cytosol
labile cell type properties
divide rapidly (most affected by chemo) short G1 (get to S phase quickly) never goes to Go
labile cells
BM gut epithelium skin hair follicles germ cells
stable cells
hepatocytes
lymphocytes
permanent cells
neurons
skeletal muscle, cardiac muscle
RBCs
permanent cell type properties
remain in Go (no cell divisions)
regenerate from stem cells
stable cell type properties
enter G1→Go when stimulated (on standby)
3 methods of proteolysis (protein degradation)
proteasomal degradation - use ubiquitin
lysosomal degradatoin
Ca2+ dependent enzymes
specialized sER in smooth muscle + skeletal muscle cells
stores Ca2+ which helps to regulate muscle contraction
sarcoplasmic reticulum
site of ATP production via TCA cycle + ETC here
apoptosis
self-replicate (own DNA)
mitochondria
B-oxidation of very long chain fatty acids (diet)
synthesis of plasmalogens (phospholipid in myelin)
contain oxidase + catalase to metabolize etoh (in hepatocytes esp)
peroxisome
process of proteasome degradation
degrade ubiquitin tagged proteins via ubiquitin protein ligases (in the proteasome)
what element causes:
muscle contraction
exocytosis of NE + hormones
Ca2+
assist in folding and transport of proteins in ER + golgi
chaperones
type of chaperone synthesized by stress = heat
rescue shock-stressed proteins from misfolding, adds ubiquitin which marks it for degradation
heat shock proteins (hsp70, hsp90)
another heat shock protein (ubiquitin)
no phosphotransferase (tags lysosomal enzymes with M6P to go to lysozome) → failure of golgi to add mannose-6-phosphate (no phosphorylation) to proteins (lysosomal enzymes) to be delivered to lysosome→ ↑ plasma levels of lysosomal enzymes
I-cell disease: inherited lysosomal storage disorder
clouded cornea, restricted joint movement, hepatosplenomegaly, high plasma levels of lysosomal enzymes
death by 8 yo
I-cell disease: inherited lysosomal storage disorder
vesicular trafficking protein that COATS ER and forms a vesicle which carries protein from ER → golgi (anterograde)
COPII
