Presentation on theme: "Cellular Anatomy and Physiology: Chapter 3. The Cellular Basis of Life: The cell is the basic structural and functional unit of life The function of an."— Presentation transcript:
The Cellular Basis of Life: The cell is the basic structural and functional unit of life The function of an organism (humans) is dependent upon the collective functions of the cells Continuity of life depends on cells
Cells: The Body’s Chemistry Labs BIO - CHEMISTRY life - chemistry Cell Function: organizing and integrating chemicals
Generalized Cell Cells come in a variety of shapes and sizes We study a “generalized” cell This is the Nucleus and Rough Endoplasmic Reticulum…
Terms to Know Plasma Membrane: Compartmentalizes H 2 O, Regulates molecular movement in and out of cell Cytoplasm:Intracellular region cytosol + cytoskeleton + organelles
Some Key Organelles Some Key Organelles.. Nucleus: Contains DNA and Controls synthetic activity of the cell Mitochondria: Responsible for oxidative metabolism in generating ATP Ribosomes: Sites of protein synthesis Others: Endoplasmic Reticulum, Golgi, Vesicles (vacuoles)…
CELLULAR PHYSIOLOGY: Overview Key “Life Functions” Of the Cell
Membrane Control of Cellular Homeostasis Diffusion Osmosis Mediated Transport Endocytosis & Exocytosis
Cellular Homeostasis Intracelluar vs. Extracellular Proteins Glycogen K+ Na+ Ca++ Cl- Selective Permeability: Some Things are selected for in, others Depends on Channels – For out: Depends on Channels – Membrane Channels that is…
It Depends…Not on Channels but on Gradients O 2 CO 2 Glucose Urea Amino Acids More on this when we look closely at molecular movement across membranes
Cell Functions = Life Functions: Reproduce Grow Adapt Transform Energy Metabolism Respiration Excretion Contribute to the function of the whole
Growth, Reproduction and Adaptation: Protein Synthesis Transcription Translation Post-Translational Modifications Mitosis and Meiosis…
Transforming Energy: ATP Homeostasis Anaerobic Metabolism Converting fuels to ATP in the Cytosol – without oxygen Aerobic Metabolism Converting fuel by-products to ATP in the Mitochondria – using oxygen
Take “2”: Review and Draw Cell Organelles Take “2”: Review and Draw Cell Organelles : Cytoplasm Endoplasmic Reticulum Golgi Apparatus Ribosomes Cytoskeleton: microtubules, filaments, intermediary filament
Membrane Specializations: Microvilli: “Little shaggy hairs” Fingerlike projections to increase the surface area of the membrane Part of the membrane Cilia: “eyelashes” NOT part of the membrane, but protein fibers extending from the cell “tail wagging” to propel substances across the cell surface
Membrane Composition Phospholipids Imbedded Proteins: *Channels, Carriers, Signal Receptors, Enzymes, Support Cholesterol, Sugar Residues
Phospolipids Have a Polar Head and a Non-Polar Tail Polar Heads:Hydrophilic – “water loving” The heads face the watery inside and outside of the cell Non-Polar Tails: Hydrophobic – “water hating” The tails hide from the water…
Phospholipid Bi-Layer Outside of Cell Inside of Cell + - Heads Tails
Selective Permeability Large molecules, and many ions cannot cross the lipid barrier Other ions/ small lipid soluble molecules are “allowed” to cross Water molecules generally move with ions or larger molecules
Concentration Gradients = Potential Energy A difference in [molecule] concentration (high vs low) across the membrane = concentration gradient
Concentration Gradients Create a “Potential” energy source Molecules will always move from high concentrations to low concentrations
Question: How does the concentration of “scent” molecules in a room change with time?
Equilibrium Balance Equal concentration of molecules on both sides of the membrane Equal movement in and out of cell
Terms: The stuff that moves Solvent: predominant material (H 2 O) Solute: molecule dissolved in the solvent Concentration Gradient: of solutes in a solvent
Terms: The way stuff moves Diffusion: Solute molecules move across membrane Facilitated Diffusion: By carriers Osmosis: Solvent (H 2 O) moves Active Transport: ATP Energy
Passive Diffusion Solutes move “downhill” along or with a concentration gradient Requires no ATP energy Small Molecules freely permeable: O 2, CO 2, urea etc And Now: A Diffusion Demonstration!
Osmosis Solvent (H 2 O) moves “down” a (H 2 O) concentration gradient Only Water Moves ! Water moves to “disperse” crowded solute molecules, when they are “trapped”
Osmotic Terms: Solute Concentrations ( Outside cell) Isotonic: Solute concentration equal on both sides of membrane Hypotonic: Solute concentration less than inside cell Hypertonic:Solute concetration more than inside cell
Cells and Solutions: When the “bathing solution” isn’t isotonic
Memory Aids…Distilled Water is Hypotonic “Gee Doc, that’s a SWELL HYPOdermic!” Cells Swell in Hypotonic solutions: Lyse
And…The Dead Sea is hypertonic “I get HYPER when my jeans SHRINK!” Cells Shrink in Hypertonic solutions: Crenation Isotonic solutions keep everyone happy
Challenge! Cystic Fibrosis is an Osmosis Problem Check out this web site on the cell http://www.usd.edu/~bgoodman/cell- ebration.html http://www.usd.edu/~bgoodman/cell- ebration.html What single membrane protein is dysfunctional in people with Cystic Fibrosis? Why can we say that CF is an “OSMOSIS” problem?
Facilitated Diffusion Carrier Mediated: Temporary “binding” Moves “downhill” with concentration gradient Glucose is “carrier mediated” NO ATP required
Active Transport Requires metabolic energy (ATP) Moves molecules “uphill” against a concentration gradient Na+/K+ Pumps
Assignment: Create a table describing the movement of molecules across plasma membranes: Like so….
Active Trans Osm Fac. Diff. Pass. Diff Mech. Energy What Moves? Carrier ? Up/Down Gradient?