Bio 2B03 final questions with
complete solutions
CAM (cell adhesion molecule) - ANS ✔✔transmembrane protein that spans the cell
tight junctions - ANS ✔✔zona occludes. cnct adjacent epi cells, seal off space between surfaces
gap junctions - ANS ✔✔directly link cytosol of 1 cell to cytosol of another
-6 connexin protein subunits comprise a hexagonal connexin hemichannel in each cell
membrane
plasmodesamata - ANS ✔✔like gap junction but in plants, connect sieve- tube elements
(inactive, specialized cells, provided ATP by companion cells) in phloem (circ system)
desmosomes - ANS ✔✔2 cells together
hemidesmosome - ANS ✔✔1 cell with ECM
adherens junction - ANS ✔✔cnct actin cytoskeleton with neighbouring cells
cadherins - ANS ✔✔critical cell adhesion molecules of adherens
-CA2+ dependent
-mediate epi cell-cell adhesions
catenin - ANS ✔✔mediates adhesion by anchoring cadherin to the actin cytoskeleton
, granulocytes - ANS ✔✔target pathogens, neutrophils, eosoniphils, basophils
-neutrophils: highest in number, target bacterial infection, extravasation
monocytes - ANS ✔✔differentiation into macrophages which engulf invading bacteria through
phagocytosis. capable of extravasation
lymphocytes - ANS ✔✔natural killer and t/b cells: extravasation, lyse virally infected cells,
antibodies as immune response
extravasation - ANS ✔✔1. signal by infection 2. transient association 3. rolling 4. slow rolling 5.
firm adhesion 6. transmigration
1. signal by infection - ANS ✔✔cytokines release at site of infection, secretory vesicles transport
p- selectin in vesicle to interact with ligand on surface of leukocyte
2. transient association - ANS ✔✔neutrophils still pushed by flow of blood
3. rolling - ANS ✔✔adhesion of neutrophil to endothelial cell slows neutrophil movement
4. slow rolling - ANS ✔✔as neutrophil gets closer to site of infection, density of selectins
increase= more connections between selectins and ligands
5. firm adhesions - ANS ✔✔PAF (platelet activating factor) can interact with PAF receptor on
neutrophil- this connection activates signalling pathway: integrins connect with their receptor,
ICAMs (change shape to open binding spot) - very strong cnxn
6. transmigration - ANS ✔✔neutrophil stopped at site of infection and crawls between endo.
cells
complete solutions
CAM (cell adhesion molecule) - ANS ✔✔transmembrane protein that spans the cell
tight junctions - ANS ✔✔zona occludes. cnct adjacent epi cells, seal off space between surfaces
gap junctions - ANS ✔✔directly link cytosol of 1 cell to cytosol of another
-6 connexin protein subunits comprise a hexagonal connexin hemichannel in each cell
membrane
plasmodesamata - ANS ✔✔like gap junction but in plants, connect sieve- tube elements
(inactive, specialized cells, provided ATP by companion cells) in phloem (circ system)
desmosomes - ANS ✔✔2 cells together
hemidesmosome - ANS ✔✔1 cell with ECM
adherens junction - ANS ✔✔cnct actin cytoskeleton with neighbouring cells
cadherins - ANS ✔✔critical cell adhesion molecules of adherens
-CA2+ dependent
-mediate epi cell-cell adhesions
catenin - ANS ✔✔mediates adhesion by anchoring cadherin to the actin cytoskeleton
, granulocytes - ANS ✔✔target pathogens, neutrophils, eosoniphils, basophils
-neutrophils: highest in number, target bacterial infection, extravasation
monocytes - ANS ✔✔differentiation into macrophages which engulf invading bacteria through
phagocytosis. capable of extravasation
lymphocytes - ANS ✔✔natural killer and t/b cells: extravasation, lyse virally infected cells,
antibodies as immune response
extravasation - ANS ✔✔1. signal by infection 2. transient association 3. rolling 4. slow rolling 5.
firm adhesion 6. transmigration
1. signal by infection - ANS ✔✔cytokines release at site of infection, secretory vesicles transport
p- selectin in vesicle to interact with ligand on surface of leukocyte
2. transient association - ANS ✔✔neutrophils still pushed by flow of blood
3. rolling - ANS ✔✔adhesion of neutrophil to endothelial cell slows neutrophil movement
4. slow rolling - ANS ✔✔as neutrophil gets closer to site of infection, density of selectins
increase= more connections between selectins and ligands
5. firm adhesions - ANS ✔✔PAF (platelet activating factor) can interact with PAF receptor on
neutrophil- this connection activates signalling pathway: integrins connect with their receptor,
ICAMs (change shape to open binding spot) - very strong cnxn
6. transmigration - ANS ✔✔neutrophil stopped at site of infection and crawls between endo.
cells
