Membrane Transport PDF

MEMBRANE TRANSPORT Wilfred John E. Pilapil, OD PASSIVE PROCESSES DIFFUSION FILTRATION ACTIVE PROCESSES VESICULAR TRANSPORT  SOLUTION SOLVENT SOLUTE Homogenous mixture Substance present in the Present in smaller of two or more large...

MEMBRANE TRANSPORT Wilfred John E. Pilapil, OD PASSIVE PROCESSES DIFFUSION FILTRATION ACTIVE PROCESSES VESICULAR TRANSPORT  SOLUTION SOLVENT SOLUTE Homogenous mixture Substance present in the Present in smaller of two or more larger amount in a amount components solution Ex. Ex. Saltwater Air ? Seawater Rubbing alcohol  PASSIVE PROCESSES Diffusion Simple Facilitated Filtration  DIFFUSION Molecules move from higher to lower concentration Moved by Kinetic energy Molecules move down their concentration gradient  SIMPLE DIFFUSION Unassisted diffusion of solutes through the plasma membrane without interaction with carrier protein. Ex. O2, N, Co2 and alcohol Respiratory FACILITATED DIFFUSION Provides passage for certain needed substances that are both lipid-insoluble, charged and too large to pass through A membrane protein channel is used, or a membrane protein that acts as a carrier is needed Ex. GLUT4 Aquaporins  FILTRATION The process by which water and solutes are forced through the membrane by fluid, or hydrostatic pressure Ex. Blood vessels Passive process, pressure gradient  ACTI VE TRA NSP O R T ATP Uses ATP to move substances across the membrane Solute pump Moves against concentration SIMILAR TO FACILITATED DIFFUSION Protein carrier, or membrane protein channel Driven by the kinetic energy NA+-K+ PUMP PISO 3 NA 2K VESICULAR TRANSPORT Involves ATP to fuse or separate membrane vesicles and the cell membrane Moves substances in bulk without crossing the plasma membrane directly 2 types Exocytosis Endocytosis Phagocytosis Pinocytosis  VESI CULA R T RANSP O RT It is the mechanism that cells use to actively secrete hormones, mucus, and EXOCYTOSIS other cell products or to eject certain cellular wastes  VESI CULA R T RANSP O RT ENDOCYTOSIS ATP- requiring processes that take-up or engulf, extracellular substances by enclosing them in a vesicle “Into the cell” Phagocytosis Pinocytosis Engulfs large particles (Bacteria or dead cells) “Drink” or “Gulf” droplets of Extracellular fluid “Cell eating” to protect the body by ingesting bacteria Involves the uptake of fluid for absorption of ions and nutrients and foreign debris Not a means of getting nutrients Non-selective  VESI CULA R T RANSP O RT ENDOCYTOSIS ATP- requiring processes that take-up or engulf, extracellular substances by enclosing them in a vesicle “Into the cell” Receptor-mediated endocytosis Takes up specific target molecules THANK YOU SO MUCH! Raise your hand if you have any questions