Clin relevance cell meme transport

Question 1

Integral proteins

Answer 1

span entire lipid bilayer, weave in and out, interact w internal y external environment.

Question 2

Polytopic transmembrane proteins

Answer 2

a type of integral protein: include transporters, ion channels, receptors

Question 3

Peripheral proteins

Answer 3

loosely bound through electrostatic interactions w lipids or proteins

Question 4

Lipid-anchored proteins

Answer 4

tethered to membranes via covalent attachment to a lipid

Question 5

Nieman pic disease

Answer 5

deficiency in an enzyme called Acid Sphingomyelinase (A-SMase) This leads to accumulation of of SM in lysosomes of liver, spleen, CNS and bone marrow. thereby enlargement of liver y spleen. causes neurological damage

Question 6

Acid Sphingomyelinase

Answer 6

a lysosomal enzyme that breaks down sphingomyelin into ceramide and phosphorylcholine

Question 7

Hallmark of Niemann pick disease

Answer 7

Cherry red spot in eye-on macula; enlarged liver or spleen

Question 8

Phosphatidylserine (PS) as marker for apoptosis

Answer 8

In healthy cells PS is only on innerleaflet; during programed apoptosis its transfered to outer; serves as tag/label

Question 9

Distinguish apoptosis

Answer 9

Annexin and propodium iodide. Annexin tags PS on outerleaflet, PI binds to DNA after getting in from broken down membrane

Question 10

ABO blood system

Answer 10

RBCs have ‘antigens’ called A.B or O, plasma could have Anti-A, Anti-B or both; incompatible transfusion could lead to hemolysis, renal failure y shock

Question 11

Rh factor

Answer 11

RBCs express protein antigens called Rh factor. inherited in autosomal dominant, Rh+ express D antigen, Rh- dont.

Question 12

Erythroblastosis fetalis

Answer 12

disease in which there is incompatibility betwn blood of mother and fetus, when mom is Rh- and baby Rh+ mom produces ABs which can cross fetus.

Question 13

3 factors that influence membrane fluidity

Answer 13

Temp, lipid composition, cholesterol

Question 14

cholesterol: on membrane

Answer 14

can both inc or dec membrane fluidity. if membrane too rigid Cholesterol intercalates into membrane and inc fluidity. If membrane fluid cholesterol stabilizes fluidity by fitting in gaps.

Question 15

Spur cell anemia

Answer 15

a type of hemolytic anemia associated w advanced stages of alcohol liver cirrhosis that impairs cholesterol metabolism resulting in excess free cholesterol. Elevated levels of cholesterol bound to RBC membrane dec fluidity and flexibility. RBCs membrane break as pass thru capillaries. death in months. only potential cure is liver transplant

Question 16

Spur cell anemia histology

Answer 16

RBCs with spike like projections.

Question 17

Cystinuria

Answer 17

autosomal rec. defect in transporter that uptakes dimeric AA cystine y other dibasic AAs ie: arginine, lysine, ornithine. results in formation of cystine crystals or stones in kidney. Pt’s present w renal cholic (abd pain that comes in waves and is linked to kidney stones.

Question 18

Hartnup disease

Answer 18

autosomal rec, defect in transporter for non-polar or neutral AA (alanine, threonine, leucine, tryptophan) primarily in kidneys y intestines. clinical findings: cerebellar ataxia, nystagmus, photodermatitis and photosensitivity

Question 19

HARTNUP mnemonic

Answer 19

AR = autosomal rec
T = tryptophan
NU = neutral uptake is defective
P = pellagra like dermatitis

Question 20

cardiac glycosides

Answer 20

such as ouabain y digoxin act as cardiotonic (contraction-inducing) drugs, inhibit Na/K ATPase in cardiac myosites, leading to inc. in intracellular Na+, this impairs activity of 2ndary transporter ‘sodium calcium exchanger”(NCX) this leads to inc levels of Ca in sarco-endoplasmic reticulum. ; are extremely potent -fine line use

Question 21

cystic fibrosis

Answer 21

auto rec disorder, mutation in CFTR which is a chloride ion channel that mediates active transport of Cl- from inside of cells to outside using ATP, defective causes buildup of Cl-, compensated by inc in Na which makes NaCl and water follows Na leaving surface mucous layer thereby thicker mucous layer susceptible to bacterial infections