Active Transport How the cell membrane moves materials

Active Transport How the cell membrane moves materials against the concentration gradient

Describe a person who is passive. who is active.

Passive Transport: > Materials move down the concentration gradient from high to low solution concentrations > Equilibrium is reached (concentrations are equal all around) > No energy (ATP) is needed by the cell to move the materials

Active Transport: 1. Materials move up the concentration gradient, from low to high solution concentrations 2. Concentrations become unbalanced on either side of the membrane 3. Energy (ATP) is needed by the cell to move the materials

There are two ways that materials can move in/out of the cell 2. Active Transport 1. Passive Transport Diffusion Protein Pumps Facilitated Diffusion Endocytosis Osmosis Exocytosis

1. Protein Pumps use energy (ATP, electrons) to increase the concentration on one side of the membrane Chart

The Sodium-Potassium (Na+/K+) Pump uses ATP to move Na+ out and K+ into nerve, muscle and many other cells.

Protein pumps are found cooperating with protein channels in photosynthesis and cell respiration Pump Channel Chart

2. Endocytosis: Materials enter the cell without crossing the membrane—the membrane folds around the particles and forms a new vacuole inside the cell

Amoeba and white blood cells engulf large food particles through phagocytosis (a type of endocytosis). http: //www. youtube. com/watch? v=pv. Oz 4 V 699 gk (mute: annoying soundtrack) Chart

Paramecium Feeding http: //www. youtube. com/watch? v=sn 3 MTYNe 8 m. M

3. Exocytosis: Vesicles fuse to the cell membrane to release their contents (cell products or waste)

Phospholipids from vesicle membranes integrate into the plasma membrane Chart

Exocytosis in Paramecium http: //www. youtube. com/watch? v=U 9 pvm_4 -b. Hg

Key Questions: 1. What materials can diffuse through the lipid bilayer without the aid of a protein? 2. What is the difference between facilitated diffusion and the use of a protein pump? 3. What are the major differences between Passive Transport and Active Transport? 4. Explain why an animal cell bursts when placed in a hypotonic solution.