Do Now 1. is osmosis active or passive transport? Does it require energy? 2. If solute concentration is greater inside than outside the cell water flows in, the solution is? 3. If solute concentration is greater on the outside than the inside then cell water flows out, the solution is? 4. When the solute/solvent concentration is equalized the solution is? Today’s Topic: The Cell Membrane

Binder Handout (Seat) HW: 3.5 Today’s EQ: How does the concentration of molecules on either side of a membrane affect movement? Today’s objective: we will be able to explain selectively permeable in order to understand the importance of molecule transport in cells Set your desk up and silently complete the DO NOW, have your homework out to be checked

Agenda Do Now & Review DATA Days Updates Semipermeable Practice

DATA Days Remember to check your grades on the back walls on the way in. The class challenge board as been updates

Some more Data A1: 95%89% A2: 90%93% A3: 86%83% A4: 89%84% B1: 93%91% B3: 93%92% Day’s left in the quarter: 14

Updates Your first complete Unit test will be Monday September 14th Tuesday September 15th Class Competition Wall has been updated

The Cell Membrane

Cell Membrane Phospholipid Bilayer (two layers of LIPIDS) Controls the movement of molecules in and out of the cell Selectively Permeable

Phospholipid Bilayer Two layers of phospholipids in cell membrane A phospholipid -- is a lipid with 2 fatty acid tails -- has a phosphate connected to glycerol head. Two layers of phospholipids in cell membrane

Selective Permeability Selective permeability: a membrane that will allow specific types of molecules to pass through it. Also known as semipermeable. Like a security gate or screen Let me in!!

Selectively permeable Molecules may be able to enter depending on size or charge Water molecules + Cell membrane molecules Waste molecules -

Passage of Molecules Across Cell Membrane Can pass freely through membrane if --Small molecules (water) --Uncharged molecules Cannot pass freely --Large molecules --Charged molecules (positive or negative)

Transport Proteins Transport

Transport Proteins Transport Protein Hydrophilic head Hydrophobic tail Help specific molecules move through the cell membrane Stretch across both sides of the cell membrane Act like doorways or tunnels for molecules to pass through. Transport Protein Hydrophilic head Hydrophobic tail

Brain Break Some proteins are found in the plasma membranes of cells. What part of the protein is within the membrane itself? A. hydrophilic region B. Hydroponic region C. Hydrophobic region D. Hydrocoel region

Brain Break What type of macromolecule makes up cell membranes? A. carbohydrates B. lipids C. glucose D. enzymes