Cellular biology

Question 1

What protein is involved in transporting an endocytosed vesicle from the plasma membrane to the endosome?

Answer 1

Clathrin

Question 2

What molecule targets proteins in the endoplasmic reticulum for lysosome?

Answer 2

Mannose 6 phosphate

Question 3

What drugs act on microtubules?

Answer 3

Bendazoles, Paclitaxol, griseofulvin, vincristine, vinblastine, colchicine

Question 4

What findings are a/w Ehlers-Danlos syndrome?

Answer 4

Hyperextensible skin, skin bleeding, hypermobile joints, berry aneurysms

Question 5

Which arachidonic acid product causes increased bronchial tone?

Answer 5

Leukotrienes, thromboxane

Question 6

Which arachidonic acid product causes decreased bronchial tone?

Answer 6

Prostacyclin, prostaglandins

Question 7

Which arachidonic acid product causes increased platelet aggregation?

Answer 7

Thromboxane

Question 8

Which arachidonic acid product causes decreased platelet aggregation?

Answer 8

Prostacyclin

Question 9

Which arachidonic acid product causes increased uterine tone?

Answer 9

Prostaglandin

Question 10

Which arachidonic acid product causes decreased uterine tone?

Answer 10

Prostacyclin

Question 11

Which arachidonic acid product causes increased vascular tone?

Answer 11

Thromboxane

Question 12

Which arachidonic acid product causes decreased vascular tone?

Answer 12

Prostaglandin, Prostacyclin

Question 13

What are the two most abundant substances in plasma membranes?

Answer 13

Cholesterol and phospholipids

Question 14

What provides the structural framework for DNA and the nuclear envelope?

Answer 14

Nuclear laminins A B and C

Question 15

What drugs act on the arachidonic acid product pathway? What enzymes do they affect?

Answer 15

Corticosteroids inhibit phospholipase A2. NSAIDs, aspirin and acetaminophen inhibit COX. Zileuton inhibits lipoxygenase. Zafirlukast and montelukast inhibit leukotriene receptors.

Question 16

In trying to determine the genomic location of genes x, y and z, you cut multiple copies of the gene with a variety of endonucleases. The following proteins are expressed x, xz, y and z. What are the most likely locations of genes x, y, and z?

Answer 16

X and Z are expressed with each other so it means that these genes are located close together. Y is only expressed by itself and not with X or Z therefore it is located far away from those two genes.

Question 17

Describe the process of leukocyte extravasation

Answer 17

Rolling mediated by selectins, tight binding mediated by integrins, diapedesis mediated by PECAM, migration is mediated by chemotactic factors (CILK -> C5a, IL-8, LTB4, Kallikrein)

Question 18

How are molecules transported into the nucleus?

Answer 18

Nuclear localization signals that are rich in arginine, lysine, and proline.

Question 19

What histologic features are seen in apoptotic cells?

Answer 19

Cell shrinkage, nuclear shrinkage (pyknosis), basophhilia, membrane blebbing, nuclear fragmentation (karyorrhexis), formation of apoptotic bodies

Question 20

What are the signaling pathway effects of activating Gq? What are the effects of activating Gs?

Answer 20

Gq activates PLC-> IP3 (elevates intracellular calcium) and DAG (activates PKC)

Gs stimulated AC to make ATP into cAMP -> activates PKA