Slides include notes and assignments from the week of 10/5-10/9

Bell Ringer Complete Organelle “quiz” On a separate sheet of loose leaf paper define homeostasis, and explain in your own words what you think it means

Post BrainPOP definitions Cell Membrane Selectively Permeable Pores Passive Transport Diffusion Concentration Gradient Active Transport

Each group will rotate to the different stations Science Café! In group formation Each group will rotate to the different stations Everyone will read the section assigned The group will collaborate and contribute to the informational poster at each station Students within a group will take turns writing, but all students need to read and contribute at EVERY station!

Follow-up Questions Describe the similarities between enzymes and receptors If proteins were rigid (stiff), why would they make poor receptors How are receptors and transport proteins similar Scenario: a cell is bathed in fluid. However, you notice that water is flowing out of the cell… In what kind of solution is the cell immersed? Where are you on the Unit Scale?

Welcome! Please put your things away and take out a sheet of paper and a writing utensil (No textbooks today). Also, take out the scale you were given, I will be coming around to check for them.

Bell Ringer Imagine sitting in a boat that is moving downstream with the current. Then, imagine a small motor to move the same boat upstream against the current. 2. Determine which action shows passive transport and which shows active transport 3. Which requires input of energy?

KEY CONCEPT The cell membrane is a barrier that separates a cell from the external environment.

Cell membranes are composed of two phospholipid layers.

Cell membranes are composed of two phospholipid layers. The cell membrane has two major functions. cell membrane

Cell membranes are composed of two phospholipid layers. The cell membrane has two major functions. forms a boundary between inside and outside of the cell cell membrane outside cell inside cell

Cell membranes are composed of two phospholipid layers. The cell membrane has two major functions. forms a boundary between inside and outside of the cell controls passage of materials cell membrane outside cell inside cell

Hydrophilic Phosphate Head Cell membranes are composed of two phospholipid layers. Polar Hydrophilic Phosphate Head Hydrophobic Lipid Tails Non-Polar

Cell membranes are composed of two phospholipid layers. The cell membrane is made of a phospholipid bilayer. cell membrane

Cell membranes are composed of two phospholipid layers. The cell membrane is made of a phospholipid bilayer. There are other molecules embedded in the membrane. cell membrane protein cholesterol carbohydrate chain protein channel

Cell membranes are composed of two phospholipid layers. The cell membrane is made of a phospholipid bilayer. There are other molecules embedded in the membrane. cell membrane protein cholesterol carbohydrate chain protein channel

The fluid mosaic model describes the membrane Scientists have developed this model to describe the structure of the cell membrane cell membrane

Cell membranes are composed of two phospholipid layers. The cell membrane is selectively permeable. Semipermeable This allows some molecules to pass, but not all Non-polar molecules and large molecules cannot pass through the membrane Helps the cell to maintain homeostasis Some molecules can cross the membrane while others cannot.

Cell membranes are composed of two phospholipid layers. The cell membrane is selectively permeable. Semipermeable This allows some molecules to pass, but not all Non-polar molecules and large molecules cannot pass through the membrane Helps the cell to maintain homeostasis Some molecules can cross the membrane while others cannot.

Chemical signals are transmitted across the cell membrane. Receptors bind with ligands and change shape. There are two types of receptors.

Chemical signals are transmitted across the cell membrane. Receptors bind with ligands and change shape. There are two types of receptors. intracellular receptor Located inside the cell, the ligand crosses the membrane to bind with the receptor

Chemical signals are transmitted across the cell membrane. Receptors bind with ligands and change shape. There are two types of receptors. intracellular receptor membrane receptor Embedded in the cell membrane. A ligand will bind to the receptor and the receptor will send a signal to the inside of the cell

3.4 Diffusion and Osmosis KEY CONCEPT Materials move across membranes because of concentration differences.

Passive transport does not require energy input from a cell. Molecules can move across the cell membrane through passive transport. There are two types of passive transport. diffusion osmosis

Diffusion and osmosis are types of passive transport. Molecules diffuse down a concentration gradient.

Diffusion and osmosis are types of passive transport. Osmosis is the diffusion of water molecules across a semipermeable membrane.

3.4 Diffusion and Osmosis Diffusion and osmosis are types of passive transport. There are three types of solutions. isotonic hypertonic hypotonic

Some molecules can only diffuse through transport proteins. Some molecules cannot easily diffuse across the cell membrane. Facilitated diffusion is diffusion through transport proteins.

KEY CONCEPT Cells use energy to transport materials that cannot diffuse across a membrane.

Active transport requires energy input from a cell and enables a cell to move a substance against its concentration gradient. Active transport is powered by chemical energy (ATP). Active transport occurs through transport protein pumps. Cells use active transport to maintain homeostasis.

A cell can import and export large materials or large amounts of material in vesicles during the processes of endocytosis and exocytosis. Cells use energy to transport material in vesicles. Endocytosis is the process of taking material into the cell. Phagocytosis is a type of endocytosis.

A cell can import and export large materials or large amounts of material in vesicles during the processes of endocytosis and exocytosis. Cells use energy to transport material in vesicles. Exocytosis is the process of expelling material from the cell.

Interactive Reader 3.3-3.5

Take a moment to reflect on today’s lesson… What were the main ideas from the lesson? Was the information difficult? confusing, etc.? How would you rate yourself on the Unit Scale?? I always appreciate any additional feedback!