Warm up Please get out your Labs and complete the graph and questions on the back. Remember this lab is going to be turned as a product grade so try your best!

Movement through cell membranes

Diffusion Example: exchange of oxygen and carbon dioxide in lungs Molecules or ions moving from areas of higher concentration to lower concentration Difference in concentration is the concentration gradient Concentrations are equal = equilibrium

Diffusion in & out of a cell the cell membrane is permeable to that substance (fat soluble such as 02 and CO2) 2. concentration gradient exists such that the substance is at a higher concentration either outside or inside the cell.

Water molecules diffuse from higher water concentrations to lower water concentrations In solutions: higher concentration of solute, lower concentration of water; lower concentration of solute, higher concentration of water. Greater the concentration of solute (proteins), lower water concentration, greater osmotic pressure. Lower the concentration of solute (proteins), higher water concentration, lower osmotic pressure

Osmosis Which way is the water moving across the membrane?

Hypertonic When fluid outside the cell has greater pressure than fluid inside the cell – water leaves cell example: salt water outside our potato is a hypotonic environment If you are stranded on an island why wouldn’t you want to drink the water around you?

Hypotonic When intracellular fluid has greater pressure than extracellular – water enters cell example distilled water out side our potato is a hypotonic environment If an animal cell is over exposed it will burst. Example: Over hydration by drug user

Isotonic When inside the cell and outside the cell are the same = isotonic

NO NET MOVEMENT OF H2O (equal amounts entering & leaving) The Plasma Membrane 4/26/2017 Isotonic Solution Hypotonic Solution Hypertonic Solution NO NET MOVEMENT OF H2O (equal amounts entering & leaving) Water enters cell- can cause it to burst Water leaves cell until it “deflates” 10 G. Podgorski, Biol. 1010 10

Cell in Isotonic Solution The Plasma Membrane 4/26/2017 Cell in Isotonic Solution 10% NaCL 90% H2O ENVIRONMENT CELL NO NET MOVEMENT 10% NaCL 90% H2O What is the direction of water movement? equilibrium The cell is at _______________. 11 G. Podgorski, Biol. 1010 11

Cell in Hypotonic Solution The Plasma Membrane 4/26/2017 Cell in Hypotonic Solution 10% NaCL 90% H2O CELL H2O 20% NaCL 80% H2O What is the direction of water movement? What is the direction of water movement? 12 Water moves into the cell G. Podgorski, Biol. 1010 12

Cell in Hypertonic Solution The Plasma Membrane 4/26/2017 Cell in Hypertonic Solution 15% NaCL 85% H2O ENVIRONMENT CELL H2O 5% NaCL 95% H2O What is the direction of water movement? What is the direction of water movement? 13 G. Podgorski, Biol. 1010 13

Pass out practice problems Stop! Pass out practice problems

Warm up Why don’t you want to drink salt water? What kind of environment would drinking salt water create in your body? What would happen to your cells? If you have 95% water and 5% solute on the inside of a cell and 80% water 20% on the out side which way will the water move?

Three Types of Transport: Passive Transport (no energy needed) Includes: Diffusion, Osmosis (a type of diffusion), and Facilitated Diffusion 2. Active transport (energy required) 16

Three Forms of Transport Across the Membrane The Plasma Membrane Three Forms of Transport Across the Membrane 4/26/2017 17 G. Podgorski, Biol. 1010 17

Passive Transport Simple Diffusion Doesn’t require energy The Plasma Membrane 4/26/2017 Passive Transport Simple Diffusion Doesn’t require energy Molecules move from high to low concentration 18 G. Podgorski, Biol. 1010 18

Facilitated diffusion The Plasma Membrane 4/26/2017 Passive Transport Facilitated diffusion Doesn’t require energy Uses transport proteins to move high to low concentration Examples: Glucose or amino acids moving from blood into a cell. 19 G. Podgorski, Biol. 1010 19

Facilitated Diffusion The Plasma Membrane 4/26/2017 Facilitated Diffusion Molecules will move through the pores in Protein Channel copyright cmassengale 20 G. Podgorski, Biol. 1010 20

Active Transport Requires energy or ATP The Plasma Membrane 4/26/2017 Active Transport Requires energy or ATP Moves materials from LOW to HIGH concentration AGAINST concentration gradient 21 G. Podgorski, Biol. 1010 21

Active transport

Active Transport Similar to facilitated diffusion Differs in that particles are moving from areas of low concentration to high concentration Carrier proteins also called pumps Examples: sugars, amino acids; sodium, potassium, calcium, and hydrogen ions Also absorb nutrients into cells of the intestinal walls

Exocytosis- moving things out. The Plasma Membrane Moving the “Big Stuff” 4/26/2017 Exocytosis- moving things out. Molecules are moved out of the cell by vesicles that fuse with the plasma membrane. This is how many hormones are secreted and how nerve cells communicate with one another. 24 G. Podgorski, Biol. 1010 24

The Plasma Membrane 4/26/2017 REVIEW QUESTIONS How does osmosis or Diffusion play a role in the human body? What is the main difference between Passive transport and Active transport? What is endocytosis and exocytosis? What happens if a red blood cell is in a hypertonic solution? Hypotonic? Isotonic? 25 G. Podgorski, Biol. 1010 25