Which of the following is NOT true about unicellular organisms? A) They are simple organisms B) They are made of only one cell C) They do not contain a nucleus D) They can do things that multicellular organisms need trillions of cells to do

Fill in the blanks… A) This organelle controls entry into the cell.____________________ B)This organelle is involved in photosynthesis. ____________________ C) This organelle is used to convert energy for use by the cell. ____________________ D) This organelle provides support for the cell.________________________________ _______________________

2.4 How Substances Move Into & Out of Cells Copy This Down 2.4 How Substances Move Into & Out of Cells Objectives: 1) You will be able to describe an overview of how substances move in & out of the cell 2) Have a lab opportunity to see the results of osmosis Why did God make only one Yogi Bear? Because when he tried to make a second one he made a Boo-Boo.

WARNING! The following material can be complicating. You NEED to stay focused otherwise you will get lost very easily Lab Demo 2 types we’ll be talking about…

Copy This Down 1) Diffusion Movement of particles of a substance from an area of higher concentration to an area of lower concentration It’s a balancing out process of the particles No energy required

Diffusion Demo

Diffusion Demo Diffusion from a Sealed Container

Diffusion in the Real World…

2) Osmosis Not Spelt Ozzmosis…

Osmosis Special kind of diffusion Copy This Down Osmosis Special kind of diffusion Diffusion of water through a selectively permeable membrane So what does this mean? Water particles are small enough to diffuse through the cell membrane with ease, depending on the concentration gradient (H  L) What’s the big deal? Osmosis is vital to the survival and health of cells

Selectively permeable Copy This Down Selectively permeable A membrane with very small openings that allow particles of some substances, but not others, to pass through. (Based on size)

For your reference… A permeable membrane allows all materials to go in & out Like an open door An impermeable membrane does not allow anything in or out. Like a wall

Diffusion & the Cell Membrane Copy This Down Diffusion & the Cell Membrane Particles of many substances move in & out of cells by diffusion However, the cell membrane acts like a filter with its tiny openings, allowing some particles to go through if they are small enough (I.e. semi-permeable!) Cell Demo Iodine particles are small enough to enter the Ziploc bag. Cornstarch particles are too big to leave the Ziploc bag.

Example A = Water = Solute A Cell Membrane Outside of Cell Inside of Cell

Example A- Process = Water = Solute A Cell Membrane Outside of Cell Inside of Cell High Water Concentration High Solute A Concentration

Example A- Process = Water Cell Membrane Outside of Cell Inside of Cell High Water Concentration Low Water Concentration

Example A- Process = Solute A Cell Membrane Outside of Cell Inside of Cell Low Solute A Concentration High Solute A Concentration

Example A- Result = Water = Solute A Cell Membrane Outside of Cell Inside of Cell

Example B = Solute A = Solute B Cell Membrane Outside of Cell Inside of Cell High Concentration of solute A High Concentration of solute B

Example B Process = Solute A Cell Membrane Outside of Cell Inside of Cell High Concentration of solute A Low Concentration of solute A

Example B Process = Solute B Cell Membrane Outside of Cell Inside of Cell Is there movement inside the cell? No! Because the openings are too small! Low Concentration of solute B High Concentration of solute B

Example B Result = Solute A = Solute B Cell Membrane Outside of Cell Inside of Cell

Example C = Solute A = Solute B = Solute C Cell Membrane Outside of Cell Inside of Cell

Is there diffusion of Solute A? Which Way? = Solute B = Solute C Cell Membrane Outside of Cell Inside of Cell

Is there diffusion of Solute B? Which Way? = Solute A Is there diffusion of Solute B? Which Way? = Solute B = Solute C Cell Membrane Outside of Cell Inside of Cell

Is there diffusion of Solute C? Which Way? = Solute A Is there diffusion of Solute C? Which Way? = Solute B = Solute C Cell Membrane Outside of Cell Inside of Cell

Is there diffusion of the nucleus? Which Way? = Solute A Is there diffusion of the nucleus? Which Way? = Solute B = Solute C Cell Membrane Outside of Cell Inside of Cell

Is there diffusion of the mitochondria? Which Way? = Solute A Is there diffusion of the mitochondria? Which Way? = Solute B = Solute C Cell Membrane Outside of Cell Inside of Cell

Osmosis…a little more detailed Osmosis in plant and animal cells Plant cells contain cell walls, animal cells do not So? If water rushes into a plant cell, it becomes turgid If water rushes into an animal cell, it bursts! If water leaves a plant cell, it becomes flaccid If water leaves an animal cell, it shrinks

Osmosis in Us…

3 Terms that you will see in high school (and could help you for lab reports…)

1) Isotonic A balance of water going in & out of cell

2) Hypertonic Solution Solution with high concentration of solutes Salt water solution Water leaves the cell, and it shrivels Potentially fatal

3) Hypotonic Solution Solution with the lower concentration of solutes Distilled water solution Water enters the cell, and the cell swells Potentially fatal

Summary Cells need an optimal amount of water concentration There needs to be a balance inside & outside of the cell If too much water enters and/or leaves the cell, the cell may die

Looking at cells that are hypotonic, isotonic, hypertonic! LAB TIME Looking at cells that are hypotonic, isotonic, hypertonic!

Homework! Check & Reflect P. 119 # 1,2,3,4,5 Due next class