Cells in Action. Exchange with the environment

Transcription

1 Cells in Action Exchange with the environment

2 Diffusion NOT this kind of CONCENTRATION! Diffusion is the movement of particles from an area of high concentration to an area of low concentration. High Concentration of students Low concentration of students

3 What diffusion looks like:

4 Osmosis Osmosis is the diffusion of water through a semipermeable membrane from an area of high concentration to an area of low concentration. Semipermeable: SEMI means half, partial, or incomplete. It carries enough goods in a year to fill literally millions of semi trucks. The the winner of those semi-final matches will go to the final round against each other. Permeable comes from permeate When the skunk s spray began to permeate the car, my sister and I jumped out the vehicle and ran down the road. The light will permeate through the curtain when the sun rises.

5 Osmosis Cells are semi-permeable

6 Passive Transport The movement of particles, from an area of high concentration to an area of low concentration, across a cell membrane without the use of energy. Osmosis and diffusion are both types of passive transport Particles pass through a protein channel in the cell membrane. Uses energy Does not use energy

7 Active Transport When the cell uses energy to move particles across the cell membrane, usually from an area of LOW concentration to an area of HIGH concentration.

8 Review Your backpack will not let your pencils or your books pass through, BUT, if you poured water into your backpack, would you discover that your backpack is semipermeable or not permeable (impermeable)? semipermeable When particles move from a crowded area (high concentration) to an uncrowded area (low concentration), is this called diffusion or osmosis? Diffusion When particles move across a cell membrane without the use of energy, what is this called? Passive Transport When water moves from an area of high concentration to an area of low concentration, is this called diffusion or osmosis? Osmosis

9 REVIEW What is this picture an example of? Diffusion What is this picture an example of? Active Transport

10 Cell Transport Part II Endocytosis Endo = within or inside Cyto = cell As in endoplasmic (inside the plasma or cytoplasm) Endocytosis is when a cell uses active transport to bring a large molecule inside the cell. Includes pinocytosis (cell drinking) and phagocytosis (cell eating) White blood cells use this method to engulf and destroy bacteria Exocytosis Exo = Outer or outside Cyto = cell As in Exoskeleton (insects, lobster) Exocytosis is when a cell uses active transport to bring large molecules to the outside of the cell. Cells remove waste in this way.

11 Endocytosis Exocytosis

12 Review When a cell eats what is it called endocytosis or exocytosis? Endocytosis When a cell expels waste, what is it called? Exocytosis Is endocytosis and exocytosis an example of active or passive transport and why? Active transport because energy is used In exocytosis, how do vesicles release their contents to the exterior of the cell? The membrane of the vesicle fuses with the membrane of the cell. What does endocytosis and exocytosis have in common? Both use energy to transport materials

13 More Review! What process is this a picture of? endocytosis What process is this a picture of? Osmosis Diffusion Exocytosis

14 Create an organizer (thinking map) for CELL TRANSPORT to help you understand diffusion, osmosis, passive transport and active transport.

15 Active Transport Uses Energy Low Concentration to High Endocytosis Exocytosis Passive Transport Does not use energy High concentration to low Includes Osmosis and Diffusion and Protein channels Diffusion no membrane, particles move Osmosis water moves across a membrane