Etc. Exam 2 Flashcards
Intermediate filaments
Tensile strength due to rope-like property.
Give structure to the cytoplasm.
Form the nuclear lamina.
Can be further stabilized by accessory proteins.
Cytoplasmic (3) and Nuclear (1) intermediate filaments
Cytoplasmic: Keratin (epithelial cells) Vimentin (CT, muscle, glia) Neurofilaments (nerve cells) Nuclear: Nuclear lamina.
Microtubules
Organization main role.
Rapid assembly/disassembly.
Extend from centrosome to periphery to form tracks for vesicles, organelles, etc.
Form mitotic spindle, cilia, flagella.
+ and - end of microtubules
+ grows faster
- nucleating site
Drugs affecting microtubules and their affect (3)
Taxol: binds and stabilizes microtubules.
Colchicine and Vinblastin: bind tubulin dimers and prevent polymerization.
Microfilaments
Acting filaments.
In all cells.
Unstable.
Essesntial for cell movement.
Drugs affecting actin filaments (3)
Phalloidin: binds and stabilizes filaments.
Cytochalasin: Caps filament plus ends, stopping poymerization.
Latrunculin: Binds monomers and prevents polymerization.
ECM and basal lamina (3)
- Their components produced intracellularly and secreted and aggregate.
- Interacts with cels/tissues via transmembrane proteins.
- Composition and properties controlled and vary depending on location.
Collagen (3)
- Main structural protein in ECM/connective tissues/basal lamina.
- Trimeric protein and form triple helix.
- Can associate as fibers, sheets or transmembrane structures.
Synthesis of collagen (4)
- RER: procollagen synthesized, secreted into lumen of ER.
- Hydroxylation and glycosylation occurs in lumen.
- Self-assembly of tropocollagen and synthesis of triple helix in lumen of ER and golgi.
- Procollagen secreted from cell and is cleaved to become collagen in ECM.
Cell junctions/connections (4) AOCS
Anchored: cells anchored to each other and ECM. Strcuture main role.
Occulding: seals the space between cells of an epithelium in such a way that it creates a barrier.
Channel-forming: allow passage of molecules.
Signal-relayaing: relay a message (action potential).
Cadherins
Ca2+ dependent adhesion molecule. Important in forming junction between cells. Homophilic interactions. Interacts with actin. (E, N, VE, LI cadherins)
Ig Superfamily
Ca2+ independent transmembrane glycoproteins.
Immune cell intercations.
Homo and heterophilic binding.
Involved in recognition, binding, or adhesion processes of cells.
EMT and Cadherin switching
Epithelia to Mesenchymal Transition.
Increase in N cadherin and decrease in E cahderin.
Increased invasiveness of tumor and metastatic potential.
Selectins
Ca2+ dependent glycoprotein.
Binds to EC carbs.
Low affinity for WBC allows to slow them (rolling affect).
E, L, P selectins.
Integrins
Couple ECM to cytoskeleton.
Can activate signaling pathways (RTKs, regulating cell growth, etc.)
Adhere to WBCs via B2 family to aid in transmigration.
Laminin
Fibrous protein in basal lamina. Cell attachment, differentiation, movement, etc.
Fibronectin
Aids in blood clots. Has adhesion, growth,migration and differentiation roles as well.
Elastin
Allows tissues to resume shaped.
Proteoglycans
“Filler”. Large size facilitates movement of thins through the ECM.
Transit amplifying cells
Cells that are committed to become a certain tissue type. They divide often and “transit” from stem cellto differentiated cell.
Immortal strand hypothesis
Some cells selectively retain original DNA. Original strand of DNA is preserved in stem cells from generation to generation. Helps to prevent genetic errors.
Cord blood
Undifferentiated blood from placenta. Kept as a source of hematopoetic stem cells.
Hematopoetic stem cells
Blood components (RBC, WBC, platelets).
Mesenchymal stem cells
Found in bone marrow, fat, tooth pulp.
iPS overview
Introduce TFs to adult differentiated cell to make it have pluripotent properties.. These cells are not patient specific, but have an increased risk for teratoma.
SCNT overview
Remove nucleus from egg. Add pt’s nucleus from differentiated cell. Allow blastulation to occur and remove inner cell mass, which has pluripotent cells.
High risk for ethical problems.
Components and volumes of hematocrit
Plasma: 55%
Buffy coat (WBCs and platelets): 1%
RBCs: 45%
Functions of Albumin
Responsible for exerting concentration gradient between RBC and EC tissue fluid.
Source of colloid osmotic pressure.
Carries thryoxine, bilirubin and barbiturates.
Plasma proteins
Albumins
Globulins (immuno and non immuno)
Fibrinogen
Erythrocyte cytoskeleton (5)
Glycophorin C: attaches cytoskeleton to CM.
Band 3: binds Hb and anchors cytoskeleton proteins (most abundant)
Spectrin: form lattics.
Band 4.1: interacts with glycophorin 4.1.
Ankyrin: interacts with band 3.
Neutorphils basics
Multi-lobed nucleus.
Fxn in acute injury/inflammation and bacterial infections.
Eosinophils basics
Bi-lobed nuclei.
Secrete arylsulfatase and histaminase.
Increased counts with allergies and parasitic infection and chronic inflammation.
Basophils basics
Hard to see nucleus.
Related to mast cells.
Responsible for problems associated with hypersensitivity and anaphylaxis.
T and B cells basics
Large nucleus. Cannot differentiate.
Monocytes basics
Heart-shaped nucleus.
Differentiate into phagocytes and macrophages in tissues.
