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ELAINE N. MARIEB
EIGHTH EDITION
3
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
PowerPoint® Lecture Slide Presentation by Jerry L. Cook, Sam Houston University
ESSENTIALSOF HUMANANATOMY
& PHYSIOLOGY
PART BCells and Tissues
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Adapted to fit our curriculum
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Introduction http://www.youtube.com/watch?v=1orQkyLp
JvQ&feature=fvwrel
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Cellular Physiology: Membrane Transport Membrane Transport – movement of
substance into and out of the cell
Transport is by two basic methods
Passive transport No energy is required
Active transport The cell must provide metabolic energy
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Solutions and Transport Solution – homogeneous mixture of two or
more components
Solvent – dissolving medium
Solutes – components in smaller quantities within a solution
Intracellular fluid – nucleoplasm and cytosol
Interstitial fluid – fluid on the exterior of the cell
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Selective Permeability The plasma membrane allows some materials
to pass while excluding others
This permeability includes movement into and out of the cell
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Passive Transport Processes Diffusion
Particles tend to distribute themselves evenly within a solution
Movement is from high concentration to low concentration, or down a concentration gradient
DIFFUSION ANIMATIONFigure 3.9
PRESS TO PLAY
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Diffusion animation
http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.html
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Passive Transport Processes Types of diffusion
Simple diffusion Unassisted process
Solutes are lipid-soluble materials or small enough to pass through membrane pores
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Passive Transport Processes Types of diffusion
Osmosis – simple diffusion of water Highly polar water easily crosses the plasma
membrane
Facilitated diffusion Substances require a protein carrier for
passive transport
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Osmosis and Tonicity Animation
http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_osmosis_works.html
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Cellular Tonicity and Osmotic Pressure Solute concentrations of the cellular
environment are very important
Osmotic pressure: tendency of a solution to pull water into it
Directly related to concentration of solutes in solution (the higher the solute concentration, the greater the osmotic pressure and the stronger the tendency of water to move into the solution)
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Tonicity See Poster
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Diffusion through the Plasma Membrane
Figure 3.10
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Facilitated Diffusion Animation http://highered.mcgraw-hill.com/sites/
0072495855/student_view0/chapter2/animation__how_facilitated_diffusion_works.html
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Passive Transport Processes Filtration
Water and solutes are forced through a membrane by fluid, or hydrostatic pressure
A pressure gradient must exist Solute-containing fluid is pushed from a
high pressure area to a lower pressure area
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Active Transport Processes Transport substances that are unable to pass by
diffusion They may be too large They may not be able to dissolve in the fat core of
the membrane They may have to move against a concentration
gradient Energy is required
Two common forms of active transport Solute pumping Bulk transport
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Active Transport Processes Solute pumping
Amino acids, some sugars and ions are transported by solute pumps
ATP energizes protein carriers, and in most cases, moves substances against concentration gradients
ACTIVE TRANSPORT ANIMATIONPRESS
TO PLAY
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Sodium Potassium Pump Animation http://highered.mcgraw-hill.com/sites/
0072495855/student_view0/chapter2/animation__how_the_sodium_potassium_pump_works.html
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Active Transport Processes Bulk transport
Exocytosis Moves materials out of the cell
Material is carried in a membranous vesicle
Vesicle migrates to plasma membrane
Vesicle combines with plasma membrane
Material is emptied to the outside
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Exocytosis
Figure 3.12a
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Active Transport Processes Bulk transport
Endocytosis Extracellular substances are engulfed by
being enclosed in a membranous vescicle
Types of endocytosis Phagocytosis – cell eating
Pinocytosis – cell drinking
Copyright © 2006 Pearson Education, Inc., publishing as Benjamin Cummings
Exocytosis and Endocytosis http://highered.mcgraw-hill.com/olcweb/cgi/
pluginpop.cgi?it=swf::535::535::/sites/dl/free/0072437316/120068/bio02.swf::Endocytosis%20and%20Exocytosis