FMS Summative Exam 1: Main Material

Question 1

tight junctions

Answer 1

seals the gap between epithelial cells. Apical side. Use claudins and occludins.

Question 2

adherens junctions

Answer 2

connects actin filament bundles of adjacent cells. Made cadhedrins and catenins. Ca2+ dependent.

Question 3

desmosomes

Answer 3

same as adherens but instead connects intermediate filaments. P. vulgaris= desmosomes

Question 4

gap junctions

Answer 4

allow the passage of small water soluble molecules from one cell to the next. Key protein= connexin. not found in muscle.

Question 5

JAK/STAT Pathway

Answer 5

JAK=> autophos. STAT=> phos. Dimerization => Activate TF in nucleus. Deals with hematopoetic cell proliferation.

Question 6

RAS/MAPK

Answer 6

TyrK receptor => Associated proteins => Ras => Rak => MEK=> ERK => TFs. Cell growth and proliferation.

Question 7

PI3K/ AKT

Answer 7

TyrK receptor, binds to peptide hormones,=> IRS=> PIP2=> PIP3=> PDK1=> AKT

Question 8

cAMP/ PKA

Answer 8

7transm receptor=> Gprotein=> adenylate cyclase=> cAMP=> PKA

Question 9

IP3/PKC

Answer 9

7transm receptor=> Gprotein=> Phospholipase C=> IP3+DAG=> Smooth ER=> Ca2+=> PKC

Question 10

Difference between channels and pumps

Answer 10

Channels are mechanisms of passive diffusion. Pumps indicate active transport against concentration gradients.

Question 11

ABC transporters and cancer

Answer 11

ATP Binding Cassette (ABC) Transporters use ATP and hydrolysis to move ligands from inside the cell out to the extracellular space and are one major cause of tumor resistance to chemotherapeutic agents.

Question 12

Transport path from a mRNA to plasma membrane protein.

Answer 12

Integral+ secreted proteins synthesized on ER bound ribosomes. growing peptide has signal peptide. Signal recognition peptide binds and guides to receptor near translocon on RER. completed polypeptide pooped into RER cisterna.

Question 13

Describe the effect of insulin on blood glucose level and how each organ responds.

Answer 13

Fed state receptor. Produced by beta cells in pancreas. Glut2 receptors on pancreas take in glucose which causes Ca2+ into cell and depolarization. This releases insulin. In muscle cells AKT pathway cascades to allow Glut4 to arrive on the surface of cells and intake glucose. This in turn drops glucose levels.

Question 14

Glucagon

Answer 14

Fasting state receptor. produced by the liver when senses low blood glucose. initiates the dumping of glucose stores into blood stream. raise bgl

Question 15

What are the repair pathways?

Answer 15

mismatch, BER, NER, homologous repair, end-joining.