Biology 10/29/13 Mrs. Turgeon DO NOW: 1.Get out your cell lab worksheet 2.In your notes: Describe one difference between an animal cell and a plant cell. AGENDA: 1.Finish part F of cell lab as a group 2.Take notes on diffusion and osmosis REMINDERS: 1.Science Club today after school, room 312! 2.Science Fair judges still needed

CELL LAB The lab questions are due tomorrow!

Biology 10/30/13 Mrs. Turgeon “How far you go in life depends on your being tender with the young, compassionate with the aged, sympathetic with the striving and tolerant of the weak and strong. Because someday in your life you will have been all of these.” –G. Washington Carver DO NOW: 1.Pass forward your Cell Structure Lab 2.In agenda book: “T”notes due Thursday: Sec. 8.1 ( 10 entries min.) 3.Put everything away (under your desk) in preparation for the lab AGENDA: 1.Osmosis Lab REMINDER: 1. Science Fair Judges!

Biology 10/31/13 Mrs. Turgeon Happy Halloween! “Education is the key to unlock the golden door of freedom” -George Washington Carver DO NOW: 1.Pass forward your “T” notes for In your notes: Which of the four major biomolecules is useful to us because it stores energy? AGENDA: 1.Take quiz

Diffusion and Osmosis Diffusion: Section 6.2 Osmosis: Section 8.1

Objective SWBAT explain how molecules are transported across the cell membrane.

Diffusion The net movement of molecules from an area of higher concentration to an area of lower concentration.

Diffusion Diffusion results because of the random movement of particles. Three key factors: concentration, temperature, pressure affect the rate of diffusion. Equilibrium is reached when there is an even distribution of solute molecules (water)

Osmosis The diffusion of water across a selectively permeable membrane.

Osmosis In a cell, water always moves to reach an equal concentration on both sides of the cell membrane.

Osmosis The direction of osmosis depends on relative concentrations of dissolved particles on the two sides of the membrane.

Direction of Osmosis Isotonic Solution –concentration of dissolved particles outside and inside the cell are equal. –there will be no net movement* of water. *water diffuses into and out of the cell at equal rates.

Direction of Osmosis Hyptertonic Solution –concentration of dissolved particles outside the cell is higher than in the cytosol. –water will diffuse out of the cell.

Direction of Osmosis Hypotonic Solution –concentration of dissolved particles outside the cell is lower than in the cytosol. – water will diffuse in to the cell.

Chapter 5 How Cells deal with Osmosis To remain alive, cells must compensate for the water that enters the cell in hypotonic environments and leaves the cell in hypertonic environments.

Passive Transport Movement of molecules across the cell membrane Does NOT require energy Examples: diffusion and osmosis

Facilitated Diffusion Passive transport of materials across the cell membrane using transport proteins. Examples: –Carrier Proteins –Ion Channels

Chapter 5 Facilitated Diffusion

Chapter 5 Movement of particles across the cell membrane against the concentration gradient – (lower concentration  higher concentration) Requires ENERGY!!! Example: –Carrier proteins, endocytosis, exocytosis Active Transport

Chapter 5 Active Transport Endocytosis –Cells ingest external materials by folding around them and forming a pouch. Engulfs bacteria, food etc.

Chapter 5 Active Transport Exocytosis –Excretion of materials from a cell. Expels wastes, hormones etc.