November 17, 2015 Bell Work: Can all objects move into cells? Objective: The student will be able to… Define cellular transport with 100% accuracy using notes and classroom activities.
Today in History 1869 The Suez Canal opened in Egypt, linking the Mediterranean and the Red seas. 2003 Actor Arnold Schwarzenegger was sworn in as governor of California.
Cell Membrane Phospholipid bilayer Selectively permeable Lipid: phosphate group and two fatty acids Selectively permeable Semi-permeable
Cell Transport
Cellular Transport The movement of ions or molecules across a cell membrane a movement of biochemicals and other atomic or molecular substances across cell membranes.
Passive Transport Diffusion Osmosis
Concentration Gradient A difference in concentration of a substance across a space
Equilibrium A condition in which the concentration of a substance is equal throughout a space
Diffusion The movement of a substance from an area of high concentration to an area of low concentration caused by the random motion of particles
Diffusion
Osmosis The diffusion of water across a selectively permeable membrane
Osmosis
Diffusion and Osmosis
Hypertonic Water diffuses out of the cell Fluid outside of the cell has a higher concentration of dissolved particles than fluid inside the cell Lower free water molecule concentration than cytosol Cell shrinks
Hypotonic Water diffuses into the cell Fluid outside the cell has a lower concentration of dissolved molecules than fluid inside the cell Higher free water concentration than cytosol Cell swells
Isotonic No net water movement Concentration of free water molecules is the same inside and outside of the cell Same free water concentration as cytosol Cell stays the same size
Crossing the Cell Membrane Most ions and polar molecules cannot pass across the cell membrane They cannot pass through the nonpolar interior of the lipid bilayer Transport proteins called channels provide polar passageways that allow ions and polar molecules to move across the cell membrane. Each channel only allows a specific substance through
Crossing the Cell Membrane Ion channel Transport protein that has a polar pore which ions can pass through Some are always open Others the pores can be closed by ion channel gates
Ion Channel
Facilitated Diffusion A type of passive transport that moves substances down their concentration gradient without using the cells energy. Carrier proteins: transport proteins that can bind to a substance on one side of the cell, carry the substance to the other side of the cell, and release it.
Facilitated Diffusion Carrier protein binds a specific molecule on one side of the cell membrane A change in shape of the carrier protein exposes the molecule to the other side of the cell membrane The carrier protein shields the molecule from the interior of the lipid bilayer. The molecule is then released from the carrier proteins which then returns to its original shape.
Facilitated Diffusion
Vocabulary Worksheet Write the definitions of the key terms used in today’s lesson.
Graded Papers
Ticket Out What is passive transport?