Day 14 DO NOW: What happens when you put salt on a slug or a snail Day 14 DO NOW: What happens when you put salt on a slug or a snail? AIM: What is Osmosis?

http://www.youtube.com/watch?v=PiQkebrCw8U

What is osmosis? Osmosis is the diffusion of water through a membrane. Like regular diffusion, water will move from one concentration to another until both sides are equal in concentration 10 Salt 10 Water 20 Salt 20 water 20 Salt 10 water 10 Salt 20 Water

How is osmosis different than diffusion? In diffusion, the solute (the dissolved material) moves from a high concentration to a low concentration. Remember that the solute is small molecules such as glucose, fatty acids, amino acids, oxygen, carbon dioxide and water. But because some molecules are too big to get across the membrane, water has to move in toward these large molecules in order to dilute the concentration.

What are the effects of osmosis? (a) If the concentration of water inside the cell and outside the cell is the same, there is no net osmosis occurs. Water goes in Water goes out

What are the effects of osmosis? (b) If the concentration of water is higher outside the cell than inside the cell, the water outside the cell will move inside the cell. Pop!! Water goes in (only)

What are the effects of osmosis? (c) If the concentration of water is higher inside the cell then outside the cell, the water inside the cell will move outside the cell. Water comes out (only) Salt sucks the water out of the cell

How does osmosis affect plant cells? All cells goes through osmosis. Because plant cells have a cell wall surrounding it, the cell looks differently when osmosis occurs.

If the plant cell is placed in a solution of high concentration of solute…… then the water will leave the cell causing the cytoplasm to shrink. The cell wall remains the same!!

If the plant cell is placed in a solution of low concentration of solute…… then the water will enter the cell causing the cytoplasm to swell. The cell wall begins to swell, deforming the shape!!

http://www.youtube.com/watch?v=rvIh8JvyaYA

Day 15 What is Passive and Active Transport? DO NOW: How would you define someone who is active? ____________________ How would you define someone who is passive? ___________________________ Day 15 What is Passive and Active Transport?

There are 2 ways molecules can get in a cell. 1) Passive Transport – This type of transport requires no energy (no ATP). The cell uses the natural process of different concentration and molecule size to help molecules move from one area to another.

How to Remember Passive Transport Energy (ATP) Greater Concentration Examples: Diffusion Osmosis Lesser Concentration

There are 2 ways molecules can get in a cell. (cont) 2) Active Transport – This type of transport requires energy (ATP) to move molecules across the membrane. Some molecules must go against the concentration grain, therefore they rely on protein “pumps”. To get them across.

How to Remember Active Transport Active transport that requires energy. Movement molecules from low concentration to high. Need Energy (ATP) Greater Concentration Lesser Concentration

Other Type of Active Transport Phagocytosis- Movement of large material into the cell. Cell “pinches” the membrane forming a “bubble” around the large material.

Why is Cellular Transport Important? Cells need materials in order to carry out the 8 life functions Cells need O2 and glucose to perform respiration Cells need to get rid of waste products (CO2 & excess water) Cells need to grow and repair itself Cells need molecules to break apart and recombine to make new molecules. Without cellular transport, cells could not do what they do.

Type of cellular Transport Energy / No Energy High to low Low to high Special circumstances Diffusion No energy Small molecules Osmosis water Passive Transport Diffusion/ osmosis Active Transport Energy (ATP) Large molecules / cell doesn’t want Phagocytosis Energy Large particle Cell engulfs large particles

                                                 Red Onion in tap water

Red Onion in distilled water starting to rehydrate                                                 

Red Onion eventually goes back