Title: Webstraw: Cell Bio Anki Deck / Section 11 - Cell Signalling

Q: cell signalling involves activation of [...] messangers through receptor binding
A: secondary

Q: [...] signals interact with cytosolic receptor to directly modify gene expression in nucleus
A: hydrophobic

Q: [...] signals interact with receptor on cell surface and transmits signals with intermediate proteins to reach effector inside the cell
A: hydrophilic

Q: signal [...] is the conversion of one signal to antoehr
A: transduction

4 forms of cell signalling
1. endocrine - ligand passes through blood
2. paracrine - ligand targets adjacent cell
3. autocrine - ligand produced by the same cell it targets
4. membrane attached protein - transmembrane ligand

Q: ligand binding triggers changes in the receptor; often [...]
A: dimerization

Q: Kd is the [...] constant - lower Kd = [...] affinity
A: dissociation; higher

Q: Kd represents ligand concentration required to bind [...] of cell-surface receptors
A: 50%

Q: regulation of protein activity is controlled by phosphorylation
1. [...] - adds on phosphate
2. [...] - removes phosphate
A: kinases; phosphates

G-proteins are active when bound to GTP and inactive when bound to GDP
1. GEF - activator protein
2. GAP - inactivator protein

Q: G-protein coupled receptors have 7 [...] domains
A: transmembrane

Q: G-proteins have 3 subunits
1. [...] subunit - GTP binding site
2. [...] subint
3. [...] subunit
A: alpha; beta; gamma

Q: G-protein binding
1. ligand binding recruits [...] complex to G-protein binding receptor
2. alpha subunit binds to receptor
3. alpha subunit releases GDP and binds GTP - releases [...] subunits
4. alpha subunit binds to [...] and hydrolyzes GTP to activate it
5. trimeric complex reforms
A: trimeric; beta and gamma; effector

Q: FRET demonstrates trimeric dissociation
1. [...] when associated
2. [...] when dissociated
A: 527nm; 490nm

Q: musarinic [...] receptor uses beta/gamma subunit to activate effector
A: acetylcholine

Q: [...] catalyzes formation of cyclic AMP (cAMP)
A: adenylyl cyclase

Q: adenylyl cyclase is activated and inhibited by [...] complex
A: G-protein

Q: [...] is mass activation of adenylyl cyclase causing hyperactivity of CFTR ion channel
A: cholera skin

Q: [...] is mass activation of adenylyl cyclase leading to muscus secretion and water accumulation in the lungs
A: pertussis toxin

secondary messangers: causes signal amplication
1. cAMP - activates protein kinase A (PKA)
2. cGMP - activates protein kinase G (PKG) and opens cation channels in rod cells
3. DAG - activates protein kinase C (PKC)
4. IP3 - opens Ca^2+ in ER

Q: 2 [...] binds to PKA to activate it in a cooperative fashion
A: cAMP

Q: [...] triggers cAMP production from adenylyl cyclase
A: epinephrine

increased cAMP leads to glycogen breakdown
1. epinephrine causes cAMP to activate PKA
2. PKA phosphorylates GPK to phosphorylate GP
3. active GP converts glycogen to glucose
4. PKA phosphorylates GS to inactivate it
5. PKA phosphorylates IP to activate it which inactivates PP

Q: decreased cAMP leads to glycogen synthesis
1. PP is active without [...]
2. PP removes phosphate from [...] and [...] to inactivate them
3. PP removes phosphate from GS to activate it
4. GS converts glucose to glycogen
A: PKA; GPK; GP

Q: cAMP response element (CRE) has a role in [...] formation
A: memory

Q: CRE signalling pathway
1. cAMP released from [...]
2. activation of PKA causes phosphorylation of [...]
3. [...] binds as dimer onto CRE to activate RNA polymerase
A: adenylyl cyclase; CREB; CREB

Q: phospholipase C cleaves [...] into DAG and IP3 - phospholipase C is activated by [...]
A: PIP2; g-protein

DAG/IP3 pathway
1. alpha subunit of g-protein activates phopholipase C
2. phospholipase C cleaves PIP2 into DAG and IP3
3. IP3 binds to IP3-gated Ca^2+ channels and releases Ca^2+ into cytosol
4. Ca^2+ and DAG binds to PKC to allow for phosphorylation

Q: acetylcholine activates phospholipase C and releases [...] and [...]
A: Ca^2+; calmodulin

Q: calcium ions and calmodulin activates [...] to make citrulline + NO
A: NO synthase

Q: NO binds to NO receptor and converts GTP to [...] which binds to PKG to cause relaxation of muscle cell
A: cGMP

Q: [...] treats angina as it decomposes into NO to relax muscle cells
A: nitroglycerin

Q: [...] inhibits PDE to act as a vasodilator but causes drop in blood pressure
A: viagara