Cellular Physiology & Hematology Flashcards
What are integrins?
Large family of CAMs involved in cell-cell and cell-BM adhesion.
What is the IgG superfamily?
Membrane bound immunoglobulins.
What are cadherins?
Calcium dependent CAMs
What are selectins?
Lectin-like binding domains (bind sugar moieties).
What are the 2 types of intercellular connections?
1) structural connections
2) connection that permits ion/molecular transfer
What is another name for Tight Junctions?
Zonula occludens
What is a tight junction composed of?
Occludin, Claudin, JAMs and typically surrounds the apical margin of epithelial cells.
What types of molecules do tight junctions allow to pass?
Some ions and small molecule can pass between cells between tight junctions (para cellular pathway)
Tight junctions also prevent the movement of cellular proteins
-also BBB disruption, renal disorders, and dermatological conditions like psoriasis.
What is another name for zonula adherens?
Belt desmosomes
What is the function of zonula adherens?
Functions to associate cell skeletons of adjacent cells. Along with spot desmosomes, they function to structurally link cells for stability.
What is the function of hemidesmosomes?
To anchor the basal surface of cells to the basal lamina
- functions like sticky shoes
- focal adhesions are similar but they are much more dynamic
- protein assembly/disassemble regularly
- assist in cellular movement
- provide information to cell on conditions of ECM
Describe the configuration of gap junctions.
Dodecameric channels (12) Each unit is called a connexin 6 connexins = 1 connexon Allow for intercellular communication (electrical activity) and passage of ions/small molecules without entering the ECF
What are 4 types of receptors?
1) channel-linked
2) enzyme-linked receptors
3) G-protein-coupled receptors
4) intracellular receptors
What are the steps in channel linked receptor binding?
Signal binds, channel opens, ions flow across membrane
Describe the steps in enzyme linked receptor binding.
Signal binds, enzyme activated, enzyme generates product
Describe the steps in GPCR binding.
Signal binds, G protein binds, G protein gets activated
Describe the steps in intracellular receptor binding.
Signal binds, activated receptor regulates Tc
What are 4 ways of receptor regulation?
1) ligand-gated
2) phosphorylation-gated
3) voltage-gated
4) stretch or pressure-gated
Describe the steps of Ca2+ recruitment from the ER through GPCR binding.
Binding of ligand to GPCR activates PLC which hydrolyzes PIP2 to IP3 and DAG.
IP3 goes on to release Ca2+ from the ER and DAG activates PKC.
Calcium released from the ER bind to CaBP and then goes on to elicit its physiological effects.
Describe the cAMP activation system.
Ligand binds to GPCR, GP swaps put GDP for GTP on the alpha subunit which goes on to activate adenylyl cyclase. Adenylyl cyclase catalyzes the conversion of ATP to cAMP, which then activates PKA, which goes on to phosphorylate proteins and cause physiological effects
Where are most plasma proteins made?
Liver
What are the 5 main plasma points?
Albumin Fibrinogen Transferrin Ferritin Globulins
What is the function of albumin?
Carrier protein
What is the function of fibrinogen?
Clotting material
What is the function of transferrin?
Transfers iron
What is the function of ferritin?
Stores iron (mostly in liver)