Cells Membrane Transport Fig 7 2 Cell Membrane

Cells: Membrane Transport

Fig. 7 -2 Cell Membrane Structure Hydrophilic head WATER Hydrophobic tail WATER

Cellular Physiology: Membrane Transport · Two Types of Transport: Passive and Active 1. Passive transport · Does not require energy to transport across the membrane Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3. 20

Passive Transport Processes · Diffusion · Particles tend to distribute themselves evenly within a solution · Movement is from high concentration to low concentration, or down a concentration gradient Figure 3. 8 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3. 23

Passive Transport Processes · Osmosis – the diffusion of water Osmosis & Diffusion Animation Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3. 24 b

Membrane Transport · Two Types of Transport 2. Active transport · Requires energy to transport across the membrane · During active transport, solutes move from low to high concentration or against the concentration gradient · Molecules that cannot go through the membrane use channels and solute pumps made of proteins. Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3. 20

Active Transport Processes Figure 3. 11 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slide 3. 29 b

Effects of Osmosis on Cells Type of Solution Isotonic: The solution has the same concentration of solutes (salt) as the cell. Animal Cell Plant Cell Water moves equally into and out of the cell

Effects of Osmosis on Cells Type of Solution Hypertonic: Solution has a higher solute (salt) concentration than the cell. Animal Cell Plant Cell Water leaves the cell and it loses turgor pressure And causes the cell to shrink

Effects of Osmosis on Cells Type of Solution Hypotonic: Solution has a lower solute (salt) concentration than the cell. Animal Cell Plant Cell Water enters the cell and Pushes against The cell wall Increasing the turgor pressure Causing the cell to swell and possibly burst

What type of solution do you think this red blood cell was placed in? A B C

What type of solution do you think this red blood cell was placed in? Hypotonic! A B C