Nur 0012 Lecture 6 Anatomy and Physiology 1:Outline of Last Lecture I. Chapter 2: chemistry cont.A. Eicossanoid reviewB. ProteinsC. Nucleic acidsD. ATPII. Chapter 3: cellsA. Cell theoryB. Cell sizesC. Cell membrane/phospholipid bilayerOutline of Current Lecture I. Plasma membrane: fluid mosaic modelA. Integral proteins: receptors, enzymes, channels, CAMsB. Peripheral proteinsC. MicrovilliD. CiliaII. Membrane transportThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.A. Interstitial space: extracellular space, intracellular spaceB. Passive transport: diffusion, facilitated diffusion, osmosis, tonicityC. Active transportCurrent LectureI. Plasma membrane: changes rapidly to suit its needs (fluid mosaic model, not a static picture), has hydrophilic and hydrophobic partsA. Integral proteins: has both hydrophobic and hydrophilic components allowing it to span entire membrane1. Receptors: bind to chemical messengers such as hormones sent from other cells, has binding site specific to a messenger on extracellular portion, a. Membrane bound receptors: bind to polar ligands (molecules) to startcascade of events inside cell (very rapid, only needs one ligand to complete process)1) Certain ligands and receptors have high affinity for each other2) Receptor then undergoes conformational change (changes shape)3) Releases energized G protein which runs across membrane until it binds with another protein (2nd messenger) and activates it causing some sort of big metabolic response (example: cyclic AMP), amplification, cascade effectb. Intracellular receptors (found in cytoplasm or nucleus): bind to nonpolar ligands (steroid hormones), result in formation of new proteins1) Steroid binds to receptor then the complex binds to a DNA-associated receptor2) DNA transcribed to mRNA then ribosomes help translate into a new protein3) Somewhat slower but response is more long lasting2. Enzymes: breaks down chemical messengers and terminates its effect on target cell3. Channels: always open, allows solutes to pass in and out of cella. Example, glucose channelsb. Gated channels: only open at certain timesc. Cell-identity markers: glycoproteins that distinguishes own cells from foreign cells4. Tissue typing uses marker signature to check for compatibilitya. CAMs(cell-adhesion molecules): bind one cell to anotherB. Peripheral proteinsC. Microvilli: maximize surface area for secretion and absorption, etc.1. Can be seen with light microscopeD. Cilia: special extensions of cell membrane, powered with actin and myosin filaments,aid in movement, longer than microvillia. Produce mucus to trap bacteria and other particlesb. Cilia constantly moving in same direction, walking mucus up the cellc. Example: in respiratory tractII. Membrane transportA. Interstitial space: space directly surrounding cells, fluid filled, similar compositionto the fluid of larger extracellular space1. Cell membranes selectively permeable depending on polarity (charge), shape, and sizeB. Passive transport: doesn’t require energy expenditure by cell1. Random molecular motion (Brownian motion): move from higher concentration to lower concentration2. Simple diffusion: steroids, CO2, O2 (small nonpolar molecules), move down concentration gradient3. Things move until there’s approximately even distribution inside and outside the cell (equilibrium)4. Carrier mediated/facilitated diffusion: still passive, uses a protein carrier specific for one chemical, polar molecules use thesea. Transport maximum: channel proteins can only handle so much solute at a time1) Solutes travel quickly through membrane when there’s a high concentration, but travel will eventually level out when saturated5. Osmosis: passive transport of water down its concentration gradienta. Uses aquaporin channel protein or just goes through lipid bilayerb. Water normally moves in opposite direction of solutes1) If not, a tension is created, relates to tonicity2) In tonic solution, membrane impermeable to solutes but permeable to waterc. Osmolarity: movements of both water and soluted. Most cells are isotonic to their environment: fluid inside of cell has relatively same composition as outside1) Hypertonic: fluid rushes out of cell, cell shrivels2) Hypotonic: fluid rushes into cell, cell lyses (bursts)C. Active transport: requires