(L2) Clinical Relevance of Cell Membranes and Transport Flashcards Preview

SFM - Biochem - Quiz 1 > (L2) Clinical Relevance of Cell Membranes and Transport > Flashcards

Flashcards in (L2) Clinical Relevance of Cell Membranes and Transport Deck (14)
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1
Q

What is the cause of Niemann-Pick Disease?

L2 S11 LO1

A

Deficiency in acid sphingomyelniase (A-SMase)

Lysosomal enzyme that breaks down sphingomyelin into:

  • ceramide
  • phosphorylcholine

Deficiency results in build up in lysosomes in liver, spleen, CNS, and bone marrow.

2
Q

What are the clinical indications of Niemann-Pick disease?

L2 S11 LO1

A

-“cherry red spot” in eye (slide 14)

  • hepatomegaly
  • spleenomegaly
  • neurological damage
3
Q

What is the significance of the membrane asymmetry of phosphatidylserine?

L2 S17 LO1

A

Normally found only in the inner leaflet of healthy cells.

Cells undergoing apoptosis present it on the outer leaflet as a signal for phagocytes.

4
Q

How can apoptotic cells be distinguished from necrotic cells under the microscope?

L2 S18

A

Propidium iodide can be absorbed into necrotic cells but not apoptotic cells.

6
Q

What is the molecular basis of ABO blood typing?

L2 S21-22 LO2

A

Variable carbohydrate structure of glycoproteins/lipids of the cell membrane of RBCs.

7
Q

What is the molecular basis of Rh typing?

L2 S24 LO2

A

Presence or absence of the D antigen.

8
Q

What is the cause of spur cell anemia?

L2 S30 LO3

A

Elevated cholesterol levels resulting in decreased membrane fluidity.

Results in hemolytic anemia (RBCs lyse when passing through capillaries.

Typically caused by liver dysfunction resulting in decreased cholesterol metabolism

9
Q

What are the cytologic indications of spur cell anemia?

L2 S30 LO3

A

Presence of RBCs with thorny projection; acanthocytes

10
Q

What is cystinuria?

L2 S33 LO4

A

Autosomal recessive, defect in transported for dimeric cystine.

Results in cystine crystals in the kidney.

11
Q

What is Hartnup disease?

L2 S35 LO4

A

Autosomal recessive defect in transporter for non-polar AAs (such as tryptophan)

Tryptophan required for producing of serotonin, melatonin, and niacin (NAD+).

12
Q

What are the clinical findings and exacerbating factors of Hartnup disease?

L2 S35 LO4

A
  • cerebellar ataxia
  • photodermatitis/photosensitivity

Triggered by sunlight and fever

Typically follows period of poor nutrition

13
Q

What are cardiotonic drugs and what do they do?

L2 S37-38 LO4

A

Ouabain and digoxin

Inhibit Na+/K+-ATPase of cardiomyocytes resulting in increase intracellular Na+

Increased Na+ impairs sodium calcium exchanger (NCX) resulting in increased Ca+

Increased Ca+ increases contractile force of cardiomyocytes

14
Q

What is the clinical significance of cardiotonic drugs?

L2 S38 LO4

A

Treatment of:

  • CHF
  • AFIB
  • dysrhythmias
15
Q

How does cystic fibrosis relate to cell membranes?

L2 S41-42 LO4

A

Autosomal recessive defect in cystic fibrosis transmembrane conductance regulator (CFTR), a Cl- active transporter.

Results in increased Cl- of cells in airway creating thick mucous