DO NOW Complete the Cell Membrane Review questions

DO NOW: Complete the Cell Membrane Review questions on the slip on your desk.

Let’s go over the Do Now. 1. Check all answers that are correct. To ensure a cell is capable of obtaining the appropriate amount of nutrients and is able to remove all wastes, the cell must ___ increase density ___ increase surface area ___ remove its membrane ___ reduce volume

Let’s go over the Do Now. Use the word bank to correctly label the diagram below by writing the correct letter in the blanks. D C A. Carrier protein B. Polar C. Phospholipid bilayer D. Channel protein E. Nonpolar A B E

TODAY’S TOPIC: Cellular Transport Part 1 – Passive Transport 1) 2) 3) 4) 5) LAB: Air Freshener Beads as Cells Notes Part 1: Osmosis/Diffusion Practice: Osmosis/Diffusion worksheet Notes Part 2: Facilitated Diffusion Homework: Review Worksheet – Passive Transport

Today’s Lab PROBLEM: What happens to the weight of air freshener beads when they are placed in fresh, medium salt, and high salt water?

FOR TODAY’S LAB: 1) Read the background information and answer the pre-lab questions. 2) Carefully follow each step in the directions and complete each step before moving on to the next one. 3) Record your initial data. We will take the final data next class period. Be sure to label your cups so you know which ones are yours!

What is a concentration gradient? A concentration gradient is a change in the concentration of molecules (solute) from one area to another. HIGH CONCENTRATION LOW CONCENTRATION

Concentration gradient Moving WITH/ALONG the concentration gradient (going from HIGH concentration to LOW concentration REQUIRES NO ENERGY Moving AGAINST the concentration gradient (going from LOW concentration to HIGH concentration) REQUIRES ENERGY

HIGH CONCENTRATION LOW CONCENTRATION MOLECULES MOVE FROM HIGH CONCENTRATION TO LOW CONCENTRATION IN ORDER TO SPREAD OUT THIS REQUIRES NO ENERGY

PASSIVE TRANSPORT Passive transport is the movement of molecules from an area of HIGH concentration to an area of LOW concentration (with or along the concentration gradient) NATURE ALWAYS WANTS TO BE HERE Does NOT use ENERGY H L

THREE TYPES OF PASSIVE (NO ENERGY) TRANSPORT: 1) DIFFUSION: The movement of solute from high to low concentration 2) OSMOSIS: The diffusion of water (movement of water from high to low concentration) 3) FACILITATED DIFFUSION: The movement of solute from high to low concentration with the help of a protein

(NO ENERGY REQUIRED) DIFFUSION – movement of molecules from high to low

(NO ENERGY REQUIRED) OSMOSIS – diffusion of water (still high to low)

TONICITY Comparing the concentration of SOLUTE in two solutions: Hypertonic: higher concentration of solute Hypotonic: lower concentration of solute Isotonic: the same concentration of solute HYPOTONIC ENVIRONMENT ISOTONIC ENVIRONMENT HYPERTONIC ENVIRONMENT

NOW YOU PRACTICE: Complete the OSMOSIS worksheet on your own quietly. Be sure to raise your hand if you have any questions!

(NO ENERGY REQUIRED) FACILITATED DIFFUSION The movement of solute from high to low with the help of a protein (some molecules need help!) Channel Proteins: have a tube through which molecules can pass into the cell H L Carrier Proteins: molecule binds to it and it changes shape to allow the molecule into the cell H L