Unit 1 Flashcards
What is an example of a small diffusible signaling molecule?
NO for vasodilation (also CO)
What is the highest affinity to lowest affinity receptor binding in the body?
Highest - endocrine b/c of low conc of hormones in the blood
Intermediate - paracrine b/c they have a short distance to travel
Lowest - neurons b/c they have high conc in a small space
Variable - contact dependent
Where do Eiconsinoids bind? And what inhibits its function?
Surface receptors. Cortisone and aspirin stop the inflammation.
What are the three classes of surface receptors?
Ion-linked receptor, G-protein linked receptor, enzyme-linked receptor
What is calmodulin?
A protein that changes conformation when calcium ions bind to it. Activates CAM kinases.
What does the Gq-linked receptor do?
Activates phospholipase C
What are proteins that bind phosphotyrosines called?
SH2 domains
What are two pathways for Receptor Tyrosine Kinases?
Phospholipase c (gamma) will activate DAG and IP3
Ras activation
What will Ras activate?
MAP kinase (mitogen activated protein kinase)
What are the 6 types of cell interactions called?
Tight junctions, adherens junction, desmosome junctions, gap junction, hemidesmosome junction, focal adhesions
What are the Adherens Junction?
Cell to cell interaction with cadherins, anchored by actin. Part of the stability of the epithelial tube that will become the spinal cord.
What are focal adhesions?
Uses integrins that bind the cell (actin) to the ECM
What is a desmosome junction?
Cell to cell interaction that uses cadherins, anchored by intermediate filaments (keratin)
What is a hemidesmosome junction?
Cell to ECM that uses integrins, binds to intermediate filaments.
What is Pemphigus?
Auto immune disease, antibodies against cadherins. Leads to blistering, can be fatal.
What is Epidermolysis bullosa simplex? (EBS)
Defect in keratin assembly. Leads to blistering, can be fatal.
What are the major proteins of tight junctions?
Claudin and occludin
What is the protein component of gap junctions?
Connexin, form (6 associated) pores called connexon
How can gap junctions be regulated?
Can be open by low intracellular calcium conc or high pH.
What is collagen used for?
Tensile strength. Ehlers-danlos syndrome results in stretchy skin
How is collagen made?
Types 1,2,3. Post translational modifications allow pro-collagen to form triple helix and be secreted. Collagenase clip off pro-peptides allowing collagen to form higher structure.
4 - cannot have pro-peptides clipped and will form a mesh
What gives stretch character?
Elastin (high proline conc)
What does fibrillin do?
Forms sheath around elastin to limit stretching
What is the main function of fibronectin?
Has many binding sites and can link a lot if things together. Laminin does the same with some different sites.
What is the basal lamina made of?
Type 4 collagen, laminin, proteoglycans
What is an example of a somatic mosaicism disease?
Lymphoma of leukemia
What are cohesins and condensins?
Cohesins link sister chromatids
Condensins help condense the chromosomes
What is the APC?
Anaphase promoting complex triggers securin to remove seperase which cleaves the cohesins and allows chromatids to be pulled apart.
What controls the breakdown of proteins involved with the cell cycle (securin and cyclins)?
E3 ubiquitin ligase
What are tropic factors and how are they used?
Released by target cells or nerves, will tell a nerve to survive but only enough factor for one nerve
What is Bad and what does it do?
Pro-apoptotic protein that is silenced upon phosphorylation. If it is not it opens bad channels which ever equally releases cytochrome c into the cell.
What is the large T antigen?
Produced by SV40 virus, binds Rb and P53 and promotes cancer growth.
What drug is effective against ESBLs?
Carbapenems
