Transport Processes Across the Cell Membrane Review: The Cell Membrane made of? Phosopholipids and proteins two word definition? Selectively permeable video of cell membrane complexity Gate Keeper Function Four processes diffusion facilitated diffusion osmosis active transport

Diffusion What is diffusion? Lets go to the video tape!!!!! Definition: Random movement of molecules from an area of greater concentration to an area of lesser concentration Two-word definition: random walk Diffusion animation: Diffusion animation II:

concentration gradient Diffusion System A B NaCl Pure H2O concentration gradient SPM

A B Osmosis System SPM NaCl Pure H2O The concentration gradient according to water will slope in which direction? Where is the higher concentration of water?

Osmosis Definition: The random movement of water from a area of higher concentration to an area of lesser concentration across an SPM Connected Concepts Solute: material dissolved a solution Solvent: solution in which materials are dissolved in

Osmosis Connected Concepts Which solution has more solutes? Comparative Terms Hyper: more solutes Hypo: less solutes Iso: equal amounts of solutes

A B Osmosis System SPM NaCl Which way will water move?` Pure H2O salt Pure H2O Which way will salt move? Which side is the hypertonic and which is the hypotonic? water Hypertonic Solution Hypotonic Solution more solutes less solutes

Osmosis System How do one celled organisms survive their hypotonic environments? Adaptation for survival Contractile vacuole saves the day!

Osmosis System What happens to cells when they are put into a hypertonic solution? Check out the video man! Phenomenon is called: Plasmolysis water destruction a. The cytoplasm diffuses out of the cell shrinking the volume of cytoplasm b. Plant cells lose turgor pressure which the hydrostatic pressure created by water pressing up against the cell wall

Let’s Review Transport processes Diffusion Osmosis Passive: no energy required How do molecules in lower concentration outside the cell get into the cell? Need some kind of energized system

Active Transport System SPM A B Outside cell Inside cell Which way does the concentration gradient slope for salt (yellow dots)? Need energy: ATP

PROTEINS Other Transport Processes 1. endocytosis “inside the cell” a. Phagocytosis or cell eating White blood cells like neutrophils and monocytes (watch them in action) b. pinocytosis or cell drinking Cell “drinks” in dissolved materials by trapping tiny droplets in a fold of membrane The opposite of endo would be? 1. exocytosis “outside the cell” a. Secretion of material outside the cell like wastes and cell-by products, like different? PROTEINS