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)
Anti-Signal recognition particles are seen in what disease?
Polymyositis
What do proteasomes do?
Barrel-shaped protein complex that degrades damaged or ubiquitin-tagged proteins
Parkinson disease is probably the result in
ubiquitin-proteasome system
ubiquitin-proteasome system decreases?
cell size
What other disease uses ubiquitin-proteasome system?
CFTR
Dynein and Kinesin are together called what? Dynein transports materials to what part of the body? Microtubules in general are associated with fast or slow axoplasmic transport? Give an example of microtubules
Molecular motor proteins
Dyenin Degrades Backwards to Cell Body
Slow
i. e. #1 HSV uses anterograde mechanism to go from DRG to skin
i. e. #2 Rabies uses Retrograde mechanism to go to CNS
Drugs that act on microtubules affect what stage of the cellular cycle? Drugs that act on microtubules are?
M phase
(Microtubules Get Constructed Very Poorly):
Mebendazole (antihelminthic)
Griseofulvin (antifungal)
Colchicine (antigout)
Vincristine/Vinblastine (anticancer)
Paclitaxel (anticancer)
bronchiectasis, recurrent sinusitis, male and female infertility and situs inversus are symptoms of? What is the mechanism of this disease? What can this disease lead to and why?
Kartagener syndrome, Dyenin Arm Defect=>ATPase does not function and does not cause bending or sliding of cilia=>decreased movement;
Dysfunctional fallopian tube cilia can place the egg in an ectopic place=> increased risk for ectopic pregnancy
Plasma membrane vs Fungal membrane. What cholesterol do fungal membranes contain?
Ergosterol
How does Cardiac Glycosides affect cardiac contractility? Where does Ouabain (arrow poision) bind to? Where is the ATP site of the sodium pump located?
Cardiac glycosides inhibit Na+-K+ ATPase=>inhibits Na+/Ca2+ exchange=>increases Ca2+ and increases cardiac contractility
On the cytosolic side
What is the most abundant protein in the body? Most common cartilage? How does collagen assist the body? Mnemonic for collagen?
Collagen by organizing and strengthening extracellular matrix
Type 1
“Strong, Bloody, Slippery BM”
Give examples of type 1 collagen? Decreased Type 1 collagen is found in what disease?
Bone, Skin, Tendon, Dentin, Fascia, Cornea, Late wound repair
Osteogenesis imperfecta
Type 2 collage is? Give examples of it?
Type II: cartwolage.
Cartwolage, vitreous body and nucleus pulpous
Type 3 collage is? With what disease do you see type 3 collagen deficiency?
Fine/delicate Tissue: reticulin=>blood vessels, fetal tissue, granuation, uterus
Ehlers-Danlos syndrome (vascular type); (ThreE D)
Type 4 collage is in? In which disease, is it found?
BM, Basal Lamina, Lens. Alport Syndrome and Goodpasture syndrome.
“BM, BL, L”
Where does Collagen Synthesis, Hydroxylation, Glycosylation and Exocytosis Occur? And Synthesis, Hydroxylation and Glycosylation occur in the what organelle?
Inside the fibroblast
RER
During Synthesis, Pre-procollagen is made; pre-procollagen is made up of? What content best reflects collagen synthesis? What percentage is made up of this molecule?
Glycine-X-Y (X and Y: proline and lysine)
Glycine; “Glycine best reflects Good Collagen”
1/3
Hydroxylation interacts with what two amino acids? What disease can you get if hydroxylation is NOT done properly? Explain the clinical manifestations.
Proline and Lysine
Scurvy
Deficiency of Vit C=scurvy–>vitamin C CANNOT return the Fe to its oxidized state=>defective collagen synthesis–> weak venules and capillaries–>skin ecchymosis, perifolicular hemorrhage, bleeding gums
What is the purpose of Glycosylation? If it cannot, what disease forms?
To form Triple helix
Osteogenesis Imperfecta
Blue sclerae, Hearing Loss, dental imperfections with Fractures suggests? What genetic inheritance is this disease associated with? Why does it occur?
Osteogenesis Imperfecta
Autosomal Dominant
Defect in COLA1 and COLA2=> amino acid substitution of glycine to bulkier amino=>triple helix does NOT form=>body tries to destroy the bone=>Not enough type 1 collagen=>brittle bone
Why do Osteogenesis Imperfecta patients have blue sclerae?
the choroidal veins can be seen
With proteolytic processing, the cleavage of ____________ transforms procollagen to insoluble tropocollagen
Disulfide Rich Terminals
Cross linking allows collagen to form? How does it allow it to do that and with what enzyme? If you have problems in cross linkage, what disease do you get (2)?
Lysine-Hydroxylysine cross linkage via Copper Lysyl oxidase=> collagen fibrils
- Ehlers-Dan_LOOSE_ syndrome
- Menkes (“Kinkes”) Disease
“Cross linking requires ME”
Easy Bruising, Hyperextensible skin and joints? This disease is associated with what 4 other diseases? What is common theme among them?
Ehlers Danlos
Concept: Elastic tissues=>stretch=>burst
(i.e. Blood vessels strech=> Berry/Aortic aneurysms; Organs=>stretch=>rupture; Joints stretch=>come out of socket)
Classical type is a mutation in collagen? What is associated with? Vascular type is associated with a defect in what collagen
Collagen V like a “classical piston”; Joint and Skin problems
Collagen III defect: vascular
brittle, Colorless and “kinky” hair, growth retardation, and hypotonia (lack of muscle tone)? Why does this disease occur? What genetic component is associated with this disease?
Menkes (Kinkes) Disease
X-linked Recessive=> Defective ATP7A Menkes protein=> impaired copper absorption (does not go to Brain, Muscles, Hair, and Nervous system)=>decreased lysyl oxidase (copper is a necessary cofactor)
Elastin has lots of? Elastase breaks down elastin but elastase is normally inhibited by?
Nonhydroxylated Proline, glycine and lysine residues
AAT-1
Wrinkles of aging are due to decreased?
Collagen and elastin
