TJ Guide 4

Question 1

How are intermediate filaments important clinically?

Answer 1

Because they are specific for certain cell and tissue types they can be important in identifying different types of cancer.

Positive staining for glial fibrillary acidic protein often indicates anencephaly

Question 2

What is epidermolysis bullosa simplex?

Answer 2

-intermediate filament genetic mutation (auto. dom.) which results in sensitivity to mechanical injury and blister because of a lack of desmosomes and hemidesmosomes

Question 3

Is plectin and what is the result of diseases that cause plectin mutations?

Answer 3

• links microtubules to microfilaments

- combines epidermolysis bullosa simplex, muscular dystrophy, and neurodegeneration symptoms

Question 4

In what cells are peroxisomes prominent?

Answer 4

liver and kidney (detox functions)

Question 5

What is Zellweger syndrome?

Answer 5

• lack of functional peroxisomes due to a defect in importation of peroxisomal proteins
• defects in brain, liver, and kidney (infantile death)

Question 6

What is X-linked adrenoleukodystrophy?

Answer 6

• defective oxidation of very long chain fatty acids

- Caused by defective import of ABCD1 which prevents oxidation of the long chain fatty acids

Question 7

T or F: stop transfer signals are hydrophobic.

Answer 7

T

Question 8

T of F: the lumen of the ER = the outside of the cell?

Answer 8

T

Question 9

What proteins help to repair broken DNA replication forks?

Answer 9

BRCA1/2

• These are accessory proteins for ds-DNA breaks

Question 10

Which ANS system has terminal motor ganglia?

Answer 10

Parasympathetic

Question 11

What are the 5 key features to neurotrasmitter function that allows for them to be targeted in drug therapy?

Answer 11

1. synthesis
2. storage
3. release
4. Termination of action
5. Receptor effects (IPSPs reduce APs)

Question 12

What does calcium influx trigger in neurons?

Answer 12

1. synaptotagmin (VAMP) activated and fuses to cell membrane
2. Synaptobrevin (vSNARE) attaches to syntaxin (tSNARE) on terminal membrane

(Note: botox inhibits this process)

Question 13

T or F: co-transmitters may be in the same vesicle as the primary transmitter

Answer 13

True - these modulate the speed and effects of the neurotransmitter and also may work in feedback inhibition of nearby pathways

Question 14

What is alpha1-anti-trypsin

Answer 14

• an inhibitor of elastase
• when it gets misfolded it get sent out of the ER and degraded
• THIS IS THE MAJOR GENETIC CAUSE OF EMPHYSEMA

Question 15

What is the default pathway for vesicles exiting golgi?

Answer 15

Membrane

Question 16

What allows clathrine triskeleton baskets to pinch off of the membrane?

Answer 16

Dynamin (GTPase)

Question 17

What mediates retrieval of transmembrane ER proteins back to the ER?

Answer 17

The binding of a di-lysine sequence directly to the COPI coat

Question 18

What mediates retrieval of luminal ER proteins back to the ER?

Answer 18

KDEL on c-terminus binding to the cis-golgi and going back via COPI

Question 19

What is familial hyperproinsulinemia?

Answer 19

• in the pathways of regulated secretion, the pro-insulin doesn’t undergo cleavage to mature into insulin

Question 20

What would be the result of N-acetylgucosamine phosphotransferase inhibition?

Answer 20

• There would not be localization to lysosomes because mannose would not get phosphorylated.
• This is the cause of I-cell disease

Question 21

What disease is caused by a defect in alpha-glucosidase?

Answer 21

pompe

Question 22

What type of motor does COPII bind to?

Answer 22

Dyenin

Question 23

What type of motor does Clathrin AP1 bind to?

Answer 23

kinesin

Question 24

What is the cause of gaucher’s disease?

Answer 24

-

- glycolipid accumulates in spleen and kidney

Question 25

What is the cause of Tay Sachs?

Answer 25

-

- accumulation of GM2 ganglioside