U NIT 2 S EC 7.3 Homeostasis and Transport

C ELL W ALL A. Structure Composed of cellulose (__________) Cellulose is a polysaccharide composed of smaller units called _______________ (glucose) Glucose protects and supports cell

C ELL M EMBRANE Cell Membrane: Controls what enter and leave cell through selective permeability Boundary of every cell

C ELL M EMBRANE A. Membrane Lipids Phospholipid bilayer: Polar hydrophilic head Nonpolar hydrophobic tail Steriods: Cholesterol provides strength and stability in movement

C ELL M EMBRANE

B. Membrane Proteins Integral proteins: embedded in lipid bilayer & extend from interior  exterior of CM

F LUID M OSAIC M ODEL Phospholipid bilayer acts more like a fluid than a solid

II. P ASSIVE T RANSPORT Passive Transport: the movement of substances across the cell membrane without the use of energy

T YPES OF P ASSIVE T RANSPORT Diffusion Osmosis Facilitated Diffusion

A. D IFFUSIOND IFFUSION DiffusionDiffusion: movement of molecules from an area of _______ concentration to an area of ________________ Molecules that use Diffusion: 1. _________________ 2. _________________ 3. _________________ Cool Science Trick

A. D IFFUSION Equilibrium: concentration of substances in an area is _______

B. O SMOSISO SMOSIS OsmosisOsmosis: diffusion of ________ molecules across CM from area of _______ concentration to an area of ________ concentration

W HO GETS IT ? 1) What is diffusion? 2) What is equilibrium? 3) What is osmosis?

B. O SMOSIS Direction of Osmosis: Hypotonic: Concentration of solute is lower outside the cell Hypotonic Hypertonic: Concentration of solute is higher outside the cell Hypertonic Isotonic: solutes in and outside the cell are equal Isotonic

B. O SMOSIS How cells deal w/ Osmosis: Hypotonic Environment: Plant root cells like this Cytolysis: Hypertonic Environment.: Plasmolysis:

C. F ACILITATED D IFFUSION Facilitated DiffusionFacilitated Diffusion: substances require a ____________ for transport b/c it cannot diffuse through membrane Molecules that use Facilitation Diffusion 1. ________________ 2. ________________ 3. ________________

D. F ACILITATED D IFFUSION Protein Channel: pathway for specific ion to pass through cell membraneChannel

III. A CTIVE T RANSPORT (AT) 1) AT: movement of materials from a area of ______ concentration to a _______ concentration using energy 2) Commonly used for a) _________________ b) _________________ c) _________________

III. A CTIVE T RANSPORT 3) Bulk Transport:Bulk Transport Used to transport macromolecules or a large quantity of substance A) Endocytosis: a cell will engulf external substances into cell -2 Types 1) Pinocytosis: cell ___________ 2) Phagocytosis: cell __________

E NDOCYTOSIS AND E XOCYTOSIS

III. A CTIVE T RANSPORTA CTIVE T RANSPORT B) Exocytosis: process to remove materials from cell