| Question |
Answer |
| Three cell types with regard to cell cycle |
Permanent, Stable, Labile |
| Rough Endoplasmic Reticulum rich cells |
-Mucus-secreting goblet cells of small intestine -Antibody-secreting plasma cells (ie lost of secretory protein) |
| Cell cycle: Permanent cells |
Remain in G0. If they regenerate, they regenerate from stem cells. |
| Cell cycle: Stable cells |
Enter G1 from G0 when stimulated |
| Cell cycle: Labile cells |
Never go to G0, divide rapidly with a short G1 |
| Smooth Endoplasmic Reticulum: Functions |
-Steroid synthesis -Detoxification of drugs and poisons |
| Permanent cells: cell types |
-Neurons -Skeletal and cardiac muscle -RBCs (regenerate from stem cells) |
| Stable cells: cell types |
-Hepatocytes -Lymphocytes |
| Smooth Endoplasmic Reticulum rich cells |
-Liver hepatocytes -Steroid hormone-producing cells of the adrenal cortex |
| Labile cells: cell types |
-Bone marrow -Gut epithelium -Skin -Hair follicles (think about chemotherapy side effects) |
| Rough Endoplasmic Reticulum: Functions |
-Synthesis of secretory (exported) proteins -N-linked oligosaccharide addition to many proteins |
| Neurons: name of Rough Endoplasmic Reticulum and its function |
Nissl bodies sytnhesize enzymes (eg ChAT) and peptide neurotransmitters. |
| 6 functions of Golgi apparatus |
1. Distribution center --Input: Proteins and lipids from endoplasmic reticulum --Output: Plasma membrane, lysosomes, secretory vesicles 2. Modifies N-oligosaccharides on asparagine 3. Adds O-oligosaccharides to serine and threonine residues (o |
| I-cell disease: Presentation |
-coarse facial features -clouded corneas -restricted joint movement -high plasma levels of lysosomal enzymes -fatal in childhood |
| COPI: Function |
Retrograde Intracellular transport: cis-Golgi to RER |
| COPII: Function |
Anterograde Intracellular transport: RER to cis-Golgi |
| Clathrin: Function |
Extracellular/lysosomal transport: -lysosome: trans-Golgi to lysosome -trans-Golgi to plasma membrane to endosomes (for receptor mediated endocytosis) |
| Microtubules: Diameter |
24 nm |
| Microtubules: Structure |
13 dimers of alpha/beta tubulin per circumference (each dimer bound to GTP), repeated in helical configuration |
| Microtubules: Found in ? |
-Flagella -Cilia -Mitotic spindles -Slow neuronal axoplasmic transport |
| Microtubules: Speed of growth and collapse |
Grows slowly and collapses quickly |
| Microtubules: Affected by which drugs? |
-Mebendazole/thiabendazole (antihelminthic) -Taxol (anti-breast cancer) -Griseofulvin (anti-fungal) -Vincristine/Vinblastine (anti-cancer) -Colchicine (anti-gout) |
| Microtubule polymerization defects: Found in what syndrome |
Chediak-Higashi syndrome |
| Chediak-Higashi syndrome |
Microtubule polymerization defect resulting in decreased phagocytosis |
| Cilia: Structure |
-9+2 arrangement of microtubule doublets -The 9 peripheral doublets are linked by dynein atpase |
| Cilia: Mechanism |
The 9 peripheral doublets are linked by dynein atpase, which causes bending of cilium by differential sliding of doublets |
| Molecular motors and direction of transport in cell |
Dynein: retrograde (DIES back towards nucleus) Kinesin: anterograde (MOVES kinetically forward) |
| Kartagener's syndrome: Defect |
Dynein arm defect causing immotile cilia |
| What is phosphatidylcholine also known as? |
lecithin |
| Kartagener's syndrome: Presentation |
-Male infertility (immotile sperm) -Female infertility (immotile fallopian cilia) -Bronchiectasis and recurrent sinusitis (bacteria and particles not pushed out) -Situs inversus |
| What syndrome is situs inversus associated with? |
Kartagener's |
| Plasma membrane: composition |
-Cholesterol (~50%) -Phospholipids (~50%) -Sphingolipids -Glycolipids -Proteins |
| What is lecithin also known as? |
phosphatidylcholine |
| Plasma membrane: melting temperature association |
High cholesterol or long saturated fatty acid content means increased melting temperature |
| Where is phosphatidylcholine found? |
Major component of: 1. RBC membranes 2. myelin 3. bile 4. surfactant (DPPC- dipalmitoyl phosphatidylcholine) |
| Drugs that inhibit the sodium-potassium pump |
-Ouabain -Cardiac glycosides (digoxin, digitoxin) |
| Ouabain: Mechanism |
Inhibits Na-K atpase by binding to K site. |
| What process uses phosphatidylcholine? |
Esterification of cholesterol with LCAT (lecithin-cholesterol acyltransferase) |
| Cardiac glycosides: Mechanism |
Inhibits Na-K atpase, increasing cardiac contractility |
Buen Viaje lv.2 ch 8
