Diffusion and osmosis LT SWABT describe and compare different mechanisms of substance transport into and out of cells (e.g. diffusion, osmosis, passive and active transport)

Do gummy bears grow up?

Have you ever bought a bag of gummy bears? Are all gummy bears approximately the same size?

Do gummy bears grow up? Let’s check this out!!

Hands on activity Here are your gummy bears! Your job will be to PREDICT & OBSERVE what happens to your gummy bears when you merge them into water First, make a prediction: what does it happen to the gummy bears if you put them in water? Then, record the weight of your gummy bear

Possible questions Does the color affect what is going to happen to the gummy bear? Is the color going to dissolve? Will the size of gummy bear change in water? Make a prediction Discuss it with your partner

Diffusion and Osmosis

Passive transports: diffusion (simple & facilitated) and osmosis Active transport

Materials move across membranes because of concentration differences. Diffusion and Osmosis

Passive transport does not require energy input from a cell. Molecules can move across the cell membrane through passive transport. There are two types of passive transport. osmosis diffusion Diffusion and Osmosis

Molecules move from high to low concentration Diffusion – move from HIGH to LOW concentration

Diffusion Move from HIGH to LOW concentration – passive transport – no energy needed diffusion

Simple Diffusion Move from HIGH to LOW inside cell outside cell Which way will fat move? fat LOW HIGH

Facilitated Diffusion Move from HIGH to LOW through a channel inside cell outside cell sugar Which way will sugar move? sugar LOW HIGH

Diffusion - Summarize Move from HIGH to LOW concentration – directly through membrane simple diffusion no energy needed – help through a protein channel facilitated diffusion (with help) no energy needed HIGH LOW

Simple vs. facilitated diffusion inside cell outside cell lipid inside cell outside cell H2OH2O simple diffusionfacilitated diffusion H2OH2O protein channel

Active transport Cells may need molecules to move against concentration gradient – need to pump “ uphill ” from LOW to HIGH using energy – protein pump – requires energy ATP

Transport summary simple diffusion facilitated diffusion active transport ATP

Osmosis Movement of WATER into a region of higher solute concentration osmosis diffusion of water

Osmosis (diffusion of water) Ec

White board What’s the main difference between passive and active transport?

White board How many types of passive transport do you know?

White board Describe the facilitated passive transport Why is it called “facilitated” passive transport?

White board What are protein channels?

White board Describe active transport

White board What is osmosis?

White board Is osmosis a passive or active transport mechanism?

There are three types of solutions. isotonic Diffusion and Osmosis hypotonic hypertonic

Isotonic solution

Hypertonic solution

Hypotonic solution

Keeping water balance Cell survival depends on balancing water uptake & water loss freshwaterbalancedsaltwater

J-TPS

Can you reverse the process? How?