Read the Background Info now…

Set up Gummy Bear Lab: 1. Write a prediction/hypothesis to answer the question written at the top of your lab sheet. 2. Fill out BEFORE soaking data in the table by measuring with a ruler 3. Determine MASS using an electronic balance…push ON and then TARE before putting gummy bear on balance. 4. Fill in “before” data in the 2nd and 3rd blank for the percent change math problems 5. Write initials on side of cup, place gummy bear inside and fill with water until it covers gummy bear 6. Place in back of room until tomorrow!

Cellular Transport Notes Homeostasis, Passive Transport, Diffusion, Osmosis, & Active Transport

Learning Questions How do cells maintain homeostasis in changing environments? How do cells take in nutrients in order to grow and divide and to make needed materials? How do you explain the relationship between the structures and functions of cell organelles?

Get Ready to take notes!

Objective of the Unit Explain that cells need to maintain homeostasis Explain passive transport and diffusion Define the process of osmosis Explain the process of active transport and the role of ATP Explain the processes of endocytosis and exocytosis

CELLS AND THEIR ENVIRONMENT: HOMEOSTASIS

LIFE’S BALANCING ACT If you are too hot or too cold your body temperature is out of balance

When we are too cold we shiver, it warms us up When we are too hot we sweat, it cools us down.

Sweating and shivering are the body’s response to extreme temperature. They help the body return to a temperature that is comfortable. Sweating and shivering are the body’s response to extreme temperature. The body is balanced

HOMEOSTASIS The balance that all living things must maintain is called HOMEOSTASIS.

Importance of CELL BALANCE Your body is made up of cells that must stay balanced. They need the right amount of materials to maintain the proper environment for your body.

Objective of the Unit Explain that cells need to maintain homeostasis Explain passive transport and diffusion Define the process of osmosis Explain the process of active transport and the role of ATP Explain the processes of endocytosis and exocytosis

Concentration Gradient: The difference between the regions of high concentration and low concentration The steeper the concentration gradient, the faster diffusion takes place High concentration gradient Fast rate of diffusion Low concentration gradient Slow rate of diffusion

“Selectively Permeable” Membranes “Semi-Permeable” or “Selectively Permeable” Membranes A semi-permeable membrane will allow certain molecules to pass through it, but not others. Partially permeable membrane Generally, small particles can pass through… …but large particles cannot

Cellular Transport! The process by which molecules move from one side of the cell membrane to the other Two Types Include: Passive Active

Passive Transport

Passive Transport Doesn’t require energy Molecules move from high to low concentration Analogy: Like coasting down hill on a bike!

Diffusion The passive movement of MOLECULES along a concentration gradient, or from regions of high to low concentration. EX: Spraying air freshener

Diffusion occurs because the particles in gases and liquids are moving.

Diffusion Particles in a liquid or gas spread out… … from regions of high concentration… … to regions of low concentration… …until the particles are evenly spread out.

Osmosis- A type of diffusion Osmosis is the DIFFUSION of WATER molecules… … from a region of high concentration to low concentration …across a semi-permeable membrane… …until they are evenly spread out.

Passive Transport Does osmosis or diffusion require energy? No, molecules move along a concentration gradient (high to low).

Free water molecules diffuse in this direction Partially-permeable membrane More free water molecules on this side of membrane Water-solute particle is too large to pass through membrane Free water molecules diffuse in this direction

TOD: Complete the definition Osmosis is the movement of water molecules from a region of high concentration to low concentration across a semi-permeable membrane. answer

Brain Pop- Diffusion https://www.brainpop.com/science/cellularlifeandgenetics/diffusion/

Objective of the Unit Explain that cells need to maintain homeostasis Explain passive transport and diffusion Define the process of osmosis Explain the process of active transport and the role of ATP Explain the processes of endocytosis and exocytosis

Active Transport Requires Energy. ATP (form of energy made by mitochondria). Moves against the concentration gradient – LOW to HIGH

Active Transport Requires energy Moves molecules from low to high concentration Like pedaling up hill on a bike 

Endocytosis- Going “IN” to the cell Transporting material into a cell by the folding of a membrane.

Endocytosis- Going “IN” to the cell

Exocytosis- “EXITS” the cell Moves materials out of the cell

Summary What is Diffusion? What is Osmosis? What is Active Transport? What is Passive Transport?

Let’s Sketch It- Active v. Passive Transport!

Let’s Sketch It- Endocytosis v. Exocytosis

SUMMARIZER On your index card provided, answer the “Learn” question from the front board: How does the concentration of solutes outside the cell affect it?