Cell biology Summary- Unit 2 Question and Answers 2025

Cell biology Summary- Unit 2 Question and Answers 2025 juxtacrine signaling signaling molecule tethered to the cell membrane and only affects adjacent cells paracrine signaling secreted signaling molecules short distance- affect cells in local environment 6 Ways to Show Appreciation for Your Child's Teacher autocrine signaling molecules that stimulate the cell that released them neurons use synaptic (paracrine) axons can travel long distances endocrine signaling molecules enter bloodstream and travel great distances hormones steroids small hydrophobic capable of crossing membrane unaided GTPase small catalytic proteins w/ ability to bind guanine nucleotides GEF guanine nucleotide exchange factors GDP for GTP GAP GTPase activating proteins GTP to GDP GDI guanosine dissociation inhibitors prevent release of GDP Ras h, k, n - relay RTK signal rheb -mtor cell growth rep1- cAMP GEF - cell adhesion Rho Rho, rac, cdc42- relay surface signals to cytoskeleton Arf arf 1-6 regulate assembly of protein coats on intracellular vesicles rab rab1-6 regulate intracelluar vesicle traffic ran ran regulate miotic spindle assembly and nuclear transport of RNA and protein G proteins subunits localize to cytosolic side of plasma membrane by lipid anchors alpha subunit acts as GTPase capable of binding guanine nucleosides G protein family I Gs, Golf activates adenylyl cyclase, Ca2+ channels G protein family II Gi, Go, Gt inhibits adenylyl cyclase, K+ channels g family III Ga activates phospholipase C-B G family IV G 12/13 activates Rho to regulate actin cytoskeleton transmembrane receptors gated ion channel G-protein coupled receptors enzyme coupled receptors G protein-coupled receptors (GPCRs) ligand mediated GEF serpentine pattern Gated ion channels opens when ligand binds actylcholine receptor RTK insulin is ligand receptor tyrosine kinas