Start-up for October 27, 2014 As you watch the following video: Identify at least three parts of the cell you believe are shown. Explain why you believe the cell part you picked is shown. Cell Video

Objective: Students will A) Identify the 3 parts and functions of the cell membrane B) Define cellular transport and concentration C) Compare osmosis and diffusion D) Compare passive and active transport E) Predict cell response from changing salt concentrations

Movement through the membrane Ch. 7 Section 3, Pages 184-189 Cellular Transport Movement through the membrane Ch. 7 Section 3, Pages 184-189

Cell Membrane Surrounds cells Gives shape to animal cells A) Identify the 3 parts and functions of the cell membrane Cell Membrane Surrounds cells Gives shape to animal cells Inside cell wall of plant cells

Cell Membrane Made of: Lipid bilayer – 2 fat layers Protein channels A) Identify the 3 parts and functions of the cell membrane Cell Membrane Made of: Lipid bilayer – 2 fat layers Protein channels Carbohydrate Chains Semi-permeable

Semi-permeable or Selectively Permeable A) Identify the 3 parts and functions of the cell membrane Semi-permeable or Selectively Permeable Semi= “some” substances may pass Selective Based upon size & solubility H20 flows Salt remains

Cell Membrane Hydrophillic and Polar inside – attracts water A) Identify the 3 parts and functions of the cell membrane Cell Membrane Hydrophobic and Non-polar Outside – repels water Does the cell like to lose or keep water? Keep so scared to lose it. If you are scared of spiders, what are you called? Inside is phobic. Hydrophillic and Polar inside – attracts water Hydrophobic and Non-polar Outside – repels water

Cellular Transport Substances moved? How moved? B) Define cellular transport and concentration Cellular Transport Substances moved? How moved? What is passive and active transport? When referring to transport we are talking about what substances are moved? How are they moved?

Solution Concentration: B) Define cellular transport and concentration Solution Concentration: Like density = # molecules per volume of container Low or High Concentration? * * * * * * * * * * * * * * * * * * * * High Conc. * * Low Conc.

Diffusion Movement of molecules: gas or liquid C) Compare osmosis and diffusion Diffusion Movement of molecules: gas or liquid Law of Diffusion: From High Concentration to Low Concentration Balance the crowding

Diffusion of gases……. CO2 High, O2 Low Blood from lungs = O2 High, B) Compare osmosis and diffusion Diffusion of gases……. Blood from lungs = O2 High, CO2 Low CO2 O2 CO2 High, O2 Low

Osmosis Movement of water Special case of diffusion Think H2Osmosis C) Compare osmosis and diffusion Osmosis Movement of water Special case of diffusion Think H2Osmosis

Equilibrium H2O H2O H2O Osmosis balanced Isotonic Solution C) Compare osmosis and diffusion Equilibrium H2O H2O H2O “Equi” = Equal concentrations on both sides of membrane Osmosis balanced Isotonic Solution Iso means equal

In Osmosis….only H2O moves C) Compare osmosis and diffusion In Osmosis….only H2O moves Therefore focus on the water concentration. Predict the water movement given the following: 10% salt solution -H20 +NaCl 1% salt solution + H20 -NaCl H20 H20 What will happen to the water in this situation? Water flows from High to Low Concentration

Concentration Gradient D) Compare passive and active transport Concentration Gradient * * * * * *

Start Up 10/28/14 What is diffusion? What is the difference between diffusion and osmosis?

Passive Transport Diffusion or Osmosis Going with the gradient D) Compare passive and active transport Passive Transport Diffusion or Osmosis Going with the gradient No ATP energy required High Conc. To Low Conc. * * * * * * * * * *

Active Transport Against the gradient Requires ATP D) Compare passive and active transport Active Transport Against the gradient Requires ATP Low to High Concentrations Salt returning to blood in kidneys * * * * * * * * * * *

Understanding Check Active or Passive Transport? Which requires ATP energy? Which goes with the concentration gradient? Which goes against the gradient? Active Passive Active

Outside the cell Hypotonic or Hypertonic Solutions? E) Predict cell response from changing salt concentrations. Outside the cell Hypotonic or Hypertonic Solutions? Tap Water Hypotonic = “under” or low salt outside, relative to cell Hypertonic = “over” or high salt relative to cell Salt water inside cell

Plasmolysis Cell membranes shrink or expand E) Predict cell response from changing salt concentrations. Plasmolysis Cell membranes shrink or expand Dependent on salt concentrations

Sea water organism in fresh water………………. Tap Water Hypotonic Solution = Low salt concentration outside the cell High Water concentration outside Water moves? Inside Cell Bursts! Salt Water Inside Cell Low Water H20

Fresh water organism in salt water…………. Hypertonic Solution Water moves? Out of the cell Cell shrinks Salt Water High salt Low water Fresh water Inside cell= High Water H20

Plants cells bulge, not burst! Or Cell Membranes Shrink

Understanding Check 1. Draw a basic cell membrane and label the three main parts. 2. Why is the cell membrane called semipermeable? 3. Predict what will happen to a plant cell that is placed in salt water. Why does this happen?