Cell Transport and Membrane Quiz

Cell Transport Schedule

• Wednesday, December 4: Take cell test. Define terms for section 8.3. Turn in notebook for participation grade.

Cell Transport Notes (December 5)

• Notes: Page 21
• Activities: Cell Transport flash cards, 8.3 Assignment

Cell Membrane

• Homeostasis is maintained through regulation at the cellular level, down to the organ level.
• The plasma membrane controls movement of materials in and out of the cell maintaining homeostasis.

Cell Membrane Permeability

• The cell membrane is selectively permeable, being picky about what goes in and out.
• Small, nonpolar, hydrophobic & neutral molecules and water can pass easily.
• Polar and large molecules cannot pass easily.

Cell Transport Types

• Transport of materials into and out of the cell is either passive or active.

Passive Transport

• No energy required.
• Molecules move from high concentration to low concentration (down the concentration gradient).
• Examples: Simple diffusion, facilitated diffusion, osmosis.

Active Transport

• Energy (ATP) required.
• Molecules move against the concentration gradient, from low concentration to high concentration.
• Examples: Molecular pumps, exocytosis, and endocytosis.

Words to Know

• Solute: Substance that dissolves
• Solvent: Substance that does the dissolving
• Solution: Uniform mixture of two or more substances
• Concentration: Amount of solute in a solvent

Quizzes/Assignments

• December 4: Define terms from section 8.3 (graded)
• December 5: 8.3 Assignment, Cell Transport flashcards.
• Multiple Questions (notebook): True/false: Small things can easily move through cell membrane, Polar molecules easily pass through the cell membrane, Does passive transport require energy, True/false Active transport requires extra energy, What term means a uniform mixture?, (stamped)

Passive Transport: Simple Diffusion

• Molecules spread out across a membrane until equilibrium is reached.
• Equilibrium means equal concentration on both sides of the membrane.
• Molecules move down a concentration gradient from high [] to low []
• Examples include O2, CO2, and other small non-polar molecules.

Passive Transport: Facilitated Diffusion

• Transport proteins help facilitate diffusion of molecules that cannot pass through the cell membrane easily.
• Transport proteins can act as channels or carriers.
• Molecules move down the concentration gradient from high [] to low [ ].
• Examples: Large molecules like glucose, and polar molecules like calcium.

Passive Transport: Osmosis

• The simple diffusion of water across the cell membrane.
• Water molecules move from high water concentration to low water concentration.
• Equilibrium is reached when the water concentration is equal across the membrane.
• High water concentration means low solute concentration and vice versa.

Passive Transport: Osmosis (Solutions)

• Hypertonic solutions: Water concentration is lower outside the cell. Water moves out of the cell, causing the cell to shrink (shrivel).
• Hypotonic solutions: Water concentration is higher outside the cell. Water moves into the cell, causing the cell to swell.
• Isotonic solutions: Water concentration is the same inside and outside the cell. No net movement of water, cell stays the same size.

Questions/Activities (for student notebooks) (December 5)

• What term means equally concentrated on both sides of the membrane? (Equilibrium)
• What helps to facilitate the diffusion of molecules that couldn't pass through on their own? (Transport proteins)
• What are two examples of molecules that use facilitated diffusion to cross the cell membrane? (glucose, calcium)
• True or false: Transport proteins act only as carriers. (False)
• What term refers to the simple diffusion of water across the cell membrane? (Osmosis)
• Low water concentration means _____ solute concentration. (High)

Additional Schedule

• December 6: Edpuzzle on cell transport, work on 8.3 reading guide (no class time).
• December 9: Notes on diffusion and osmosis, lab: Effect of temperature on rate of diffusion, review
• December 10: Set up potato lab, finish yesterday's assignments, Osmosis review & interpreting diagrams, Osmosis Practice (get a stamp), write lab report
• December 11: Study flash cards, Brain dump on Canvas, Osmosis problems (get a stamp)
• December 12: Osmosis review, Finish osmosis problems, Finish notes on cell transport, Graphic organizer
• December 13: Graphic organizer (tape it in notebook), set up egg osmosis lab, video clip on animals (3 notes), define words on page 800
• December 16: Egg lab part 2, Finish vocabulary, Graphing practice, Review for final

Active Transport: Molecular Pumps

• A cell uses energy to pump molecules against the [] gradient across a protein channel.
• This allows the cell to concentrate key substances or remove waste quickly
• Examples include potassium (K+), chlorine (Cl-), and sodium (Na+).

Active Transport: Using Vesicles

• Endocytosis: Uses vesicles to move large particles into the cell. Example: White blood cells engulfing bacteria.
• Exocytosis: Uses vesicles to export materials out of the cell. Example: Nerve cells secreting neurotransmitters.

Additional Questions (notebook December 11)

• In hypotonic solutions, does water enter or leave the cell?
• In a hypertonic solution, what happens to the cell?(Get smaller)
• What is it called when a cell uses energy to pump molecules across the membrane? (Active Transport)
• What is it called when a cell uses vesicles to move large particles into the cell? (Endocytosis)
• What is it called when a cell uses vesicles to export materials out of the cell? (Exocytosis)