Cellular Biochemistry Flashcards
RER has two functions what are they?
*1. Site of synthesis of secretory (exported) proteins
- N-Linked oligosaccharide addition to proteins
Dendritic neurons have nissl bodies, what are they? What do they make?
Neuron RER
Peptide for neutrotransmitters for secretion
Free Ribsomes (FER) secretes?
Cytosolic and organelle proteins
Which cells have rich RER? Why is it rich?
Mucus-secreting goblet cells of the small intestine=> digestion requires alot of protein
Antibody-secreting plasma cells (Germinal Matrix)=> antibodies are made from protein
Which cells have rich SER? Why? What do they lack?
Liver Hepatocytes (for Detox)
Steroid hormone producing cells of adrenal cortex and gonads (for steriod synthesis)
Surface ribosomes
Which phase is the most variable? Shortest phase?
G1 phase (var1able);
Shortest phase (M phase; Minute phase)
p53 and Rb inhibit? Example of p53 and Rb mutation?
G1 to S progression
Li-Fraumeni syndrome
Which three tissues are permanent cell types? Do these tissue undergo hypertrophy or hyperplasia? What phase are these tissue in?
Neurons, skeletal and cardiac muscle
Hypertrophy
G0
Which two tissues are stable cell types? What phase are they allowed to go into?
Hepatocytes and Lymphocytes (Tho to Th1 or Th2)
G1 phase
Which cells are most affected by chemotherpay? Give examples of them. Why are these cells constantly regenerating?
Labile cells
Bone marrow, Gut, Skin, Hair, Germ cells
Because they never go into G0 and rapidly divide without going into G1
Stem cells of small/large bowel? Skin? Bone Marrow?
Bowel=>mucosal crypts
Skin=>stratum basale
Bone Marrow=>hematopoetic stem cells (CD34)
In I-Cell’s disease, lysosomes are?
empty
What are the presentation signs of I-Cell Disease?
clouded corneas restricted bone movement coarse facial features
I-Cell Disease is a defect in?
phototransferase failure to phosphorylate mannose residues
I-Cell Disease results in enzymes being sent?
extracellularly
LDL receptors have what kind of activity? Explain the process; the answer to the question goes from where to where?
Clathrin mediated endocytosis plasma membrane=>endosomes (i.e. LDL receptor activity)
Signal Recognition Particles transport proteins from where to where? COPI? COPII?
SRP: from the ribosome => the RER COPI: Cis golgi=>golgi (retrograde) OR Cis golgi to ER COPII: ER to cis golgi (ER TWO home)
Absent Signal Recognition Particles lead to accumulation of protein in?
cytosol (because it cannot go to the RER so it is stuck in the free ribosome)