DIFFUSION

Define diffusion and osmosis. Today’s Goals: Define diffusion and osmosis. Know where exchanges with the environment take place. Describe how particles move from areas of high concentration to low concentration.

Cells are like factories. They obtain energy and get rid of wastes. It keeps the cells healthy so they can divide. Cell division allows organisms to grow and repair injuries.

How does this exchange happen? Exchange with the environment takes place at the cell’s membrane. How does this exchange happen? DIFFUSION

Diffusion-the movement of particles from areas of higher concentration to areas of lower concentration until equilibrium is reached. Particles travel from where they are crowded to where they are less crowded. It takes no energy for diffusion.

Osmosis-the diffusion of water through a semipermeable membrane (high to low) Semipermeable—only certain substances can pass through

During osmosis, particles move from high concentration to low concentration. EQUILIBRIUM

Which direction will the particles move?

Which direction will the particles move?

Which direction will the particles move? 14% 2% Which direction will the particles move?

Gummy Bear Lab Put your name on the cup. Fill the cup with 100 mL of water. Describe the appearance of the gummy bear. Use the balance and ruler to measure the gummy bear. Place a gummy bear in the cup of water, then set the cup on TEACHER LAB TABLE!

Vocabulary Dice Activity Diffusion Osmosis Active Transport Passive Transport Endocytosis Exocytosis Vocabulary Dice Activity

Vocabulary Dice Activity If you roll a… Create a six line rhyming poem about your word. Draw a picture to represent the term. Give three examples of the term. Use the term in a sentence. Create an acrostic poem for the term. Create a multiple-choice test question for the term. Step 1: Fold your paper into six boxes like the example at the front of the room. Step 2: Fill in the vocabulary terms on your paper in the boxes. Step 3: Define each of the key terms in your own words. Step 4: Roll to determine your task for each of the vocabulary terms. Step 5: Use the key at the right to help you…and be HONEST.

Active vs. Passive Transport We know that things pass through the cell membrane…BUT… How do small and large particles pass through the cell membrane differently?

Today’s Goals: Explain how particles enter the cell. Differentiate between passive transport and active transport. Describe the processes of osmosis and diffusion.

What do you already know about the following topic? OSMOSIS

What predictions can you make about the following topic? Active and Passive Transport

What do you think is going on in the following picture?

Let’s make a study chart! PASSIVE TRANSPORT ACTIVE TRANSPORT PASSIVE TRANSPORT ACTIVE TRANSPORT Fold the paper in half. Only cut the top layer!

Under the Passive Transport flap… Moving small particles like sugar, water, or salt Example: Diffusion, Osmosis Moves from high concentration to low No energy required

Under the Active Transport flap… Requires energy Moves larger particles Moves from low concentration to high Example: Endocytosis, Exocytosis

Which letter below shows active transport? D

Which color of particles are part of active transport below?

Endocytosis and Exocytosis Chapter 3 Section 1

Active Transport! Requires energy Moves large particles into and out of cells Active Transport!

Types of Active Transport: Endocytosis—process where a cell membrane surrounds a particle and encloses the particle in a vesicle to bring the particle into the cell

Types of Active Transport: Exocytosis—process where a cell releases a particle by enclosing the particle in a vesicle that then moves to the cell surface and fuses with the cell membrane