Cell Membrane

Question 1

What phospholipids are on the outer leaflet?

Answer 1

Phosphatidylcholine and sphingomyelin

Question 2

What phospholipids are on the inner membrane?

Answer 2

phosphatidylserine and phosphatidylethanolamine

Question 3

Where are phospholipids synthesized? How are they distributed out of the cell?

Answer 3

In outer (Cytsolic) leaflet of the smooth ER where they are transported out by flipase, flopase, and scramblase.

Question 4

Mitochondria

Answer 4

Location of ATP synthesis, has two membranes : outer membrane is smooth w/ porins and inner membrane has folds called CRISTAE and ETC occurs here. The intermembrane space contains enzymes.

Question 5

Peroxisomes

Answer 5

make H2O2 using catalase, detoxifies chemicals, breaks down long fatty acids, synthesizes lipids (plasmalogens) and lysine

Question 6

Rough ER

Answer 6

protein assembly and modification

Question 7

Smooth ER

Answer 7

Synthesis of phospholipids, Ca storage, detoxification

Question 8

Golgi Apparatus

Answer 8

Produce enzymes/sort secretory vesicles after packing proteins and lipids and modifying. Can add mannose-6-phosphate tag on lysosomal acid hydrolases

Question 9

Lysosome

Answer 9

very acidic due to acid hydrolases which allows degradation of molecules and control of metabolism

Question 10

Tay Sachs Disease

Answer 10

issue w/ hexosaminidase A resulting in a buildup of ganglioside GM2= result in buildup of lysosomes leading to neurological issues such as blindness/muscle weakness/red spot in macula/death

Question 11

Cytoskeleton

Answer 11

cell movement, cell support/structure, shape
All non-membranous organelles: include microtubules, microfilaments, intermediate filaments

Question 12

Microtubules

Answer 12

composed of alpha/beta tubulin, arranged around a centrosome, important for intracellular transport via dynein and kinesin plus towing of chromosomes during mitosis

Question 13

Microfilaments

Answer 13

composed of actin, work w/ thick myosin beneath the plasma membrane and help w/ myosin to cleave mitotic cells

Question 14

Intermediate Filaments

Answer 14

Ropelike- neurofilaments that anchor nucleus in place
-Malfunction= Alzheimer’s

Question 15

Nucleolus

Answer 15

ribosome synthesis/assembly

Question 16

Alzheimer’s/Autism

Answer 16

occurs w/ errors involving plasma membrane rafts= sites of protein signaling that when impaired change cholesterol stability = neuronal membrane disorder

Question 17

Huntington’s and hypercholesterolemia

Answer 17

clathrin coated pits don’t function=
HD: leads to nerve cells wasting away leading to uncontrolled movements, LOB, loss of mobility/energy
hypercholesterolemia: can’t bind LDL results in excess LDL build up leading to atherosclerosis/ risk for MI/stroke

Question 18

Cervical Cancer

Answer 18

dysregulated ubiquitin- leads to HPV protein E6 promotes ubiquitination= suppressor of p53 removed leads to cervical cancer

Question 19

Sickle cell anemia and Duchenne’s Muscular dystrophy

Answer 19

cytoskeleton issues
Sickle cell- defective hemoglobin leads to lack of plasticity that is locked in by actin/myosin = sickle shape/obstruct microcirculation
DMD- abnormal dystrophin prevents normal anchoring and actin can’t grab cytoskeletal structure leading to muscle cells rupturing creating weakness/loss of mobility/death

Question 20

What are zona occludens? What is there purpose?

Answer 20

Zona occludens form TIGHT Junctions to control passing of fluid between the cells. They are composed of occludin and claudin.

Connection: Cholera toxin breaks them down resulting in fluid living the body= RICE water diarrea