Agenda Daily Trivia Daily Trivia Agenda Agenda Egg lab Egg lab Notes Notes Homework Homework

Cellular Transport Osmosis and Diffusion! Ch. 8 See how it flows!

Vocab Review Concentration = density of particles Concentration = density of particles Permeable = allows things to pass through Permeable = allows things to pass through Selectively Permeable = allows certain things only to pass through Selectively Permeable = allows certain things only to pass through Impermeable = allows nothing to pass through Impermeable = allows nothing to pass through Solute = you add Solute = you add Solvent = added to Solvent = added to

IMPORTANT DEFINITIONS DIFFUSION : movement of particles from higher concentration to lower concentration DIFFUSION : movement of particles from higher concentration to lower concentration OSMOSIS : diffusion of water across a selectively permeable membrane OSMOSIS : diffusion of water across a selectively permeable membrane In a cell, water always tries to reach an equal concentration on both sides of the membrane!

DIFFUSION

It’s all Greek to me! OSMOSIS comes from the Greek word osmos, which means “pushing.” Osmosis can push out a cell’s plasma membrane! It’s so pushy!

OSMOSIS

What controls OSMOSIS? 1) A concentration gradient (unequal distribution of particles on each side of a membrane) [p. 202]

During osmosis, only water diffuses across the selectively permeable membrane.

OSMOSIS

Homework Osmosis/Diffusion Worksheets Osmosis/Diffusion Worksheets

Daily Trivia Challenger Deep, part of the Mariana Trench, is the deepest part of the ocean. Challenger Deep, part of the Mariana Trench, is the deepest part of the ocean. It is 35,838 ft deep (that is almost 7 miles) It is 35,838 ft deep (that is almost 7 miles)

Gotta love the Greeks! ISOS=equalHYPO=underHYPER=over Remember your roots!

Hypotonic Solution A cell is placed in pure water A cell is placed in pure water There is a lower concentration of solutes ( dissolved substances )outside the cell than inside the cell. There is a lower concentration of solutes ( dissolved substances )outside the cell than inside the cell. Water will flow into the cell. Water will flow into the cell.

Isotonic Solution Equal concentrations of solutes inside and outside the cell. Equal concentrations of solutes inside and outside the cell. Water will flow into and out of the cell at equal rates (dynamic equilibrium) Water will flow into and out of the cell at equal rates (dynamic equilibrium) EX: Immunizations are isotonic solutions so they do not damage the cells by gain or loss of water. EX: Immunizations are isotonic solutions so they do not damage the cells by gain or loss of water.

Hypertonic Solution A cell is placed in a concentrated salt solution (seawater) A cell is placed in a concentrated salt solution (seawater) There is a higher concentration of solutes outside the cell than inside the cell. There is a higher concentration of solutes outside the cell than inside the cell. Water will flow out of the cell Water will flow out of the cell

Note: These are animal red blood cells. The size of the arrows indicates the magnitude and direction with which water moves.

Homework Letters to parents Letters to parents Finish projects Finish projects

Daily Trivia A goldfish (like most marine fish) can survive in a tank full of human blood. A goldfish (like most marine fish) can survive in a tank full of human blood.

Cellular Transport Move it along, folks…

Cellular Transport

Passive Transport: Molecules pass through the membrane by diffusion requiring no extra energy. Molecules pass through the membrane by diffusion requiring no extra energy. Ex: water and lipids Ex: water and lipids

Passive Transport

Facilitated Diffusion: passive transport across membrane with help of transport proteins. passive transport across membrane with help of transport proteins. Ex: sugars Ex: sugars “Water Wheel” “Water Wheel”

Facilitated Transport

Active Transport: ENERGY REQUIRED! = movement of materials through a membrane across a concentration gradient. = movement of materials through a membrane across a concentration gradient. This requires energy to counteract the movement of diffusion from high to low concentrations! This requires energy to counteract the movement of diffusion from high to low concentrations! Energy is in the form of ATP Energy is in the form of ATP

What is ATP? ATP = Adenosine TriPhosphate ATP = Adenosine TriPhosphate Energy transfer molecule Energy transfer molecule Created in the mitochondria Created in the mitochondria Re-chargable battery Re-chargable battery

How does active transport work? 1) Transport protein called “carrier protein” binds with particle of a specific shape 2) Protein uses energy to move particle inside 3) Particle is released into the cell 4) Protein returns to original shape.

Active Transport

How carrier proteins work!

Active Transport

Cellular Transport

What about the big boys? ENDOCYTOSIS: entering the cell ENDOCYTOSIS: entering the cell EXOCYTOSIS: exiting the cell EXOCYTOSIS: exiting the cell moving large masses of material moving large masses of material require energy (ACTIVE TRANSPORT!) require energy (ACTIVE TRANSPORT!)

Endocytosis

Exocytosis

Homework Diffusion problems (Review Session Friday AM) Diffusion problems (Review Session Friday AM)

ISOTONIC SOLUTIONS! Concentration of dissolved substances in solution is the same as concentration of dissolved substances inside the cell. Concentration of dissolved substances in solution is the same as concentration of dissolved substances inside the cell. Water inside cell is equal to water in solution. Water inside cell is equal to water in solution. Cells in isotonic solution do not experience osmosis and retain their normal shape. Cells in isotonic solution do not experience osmosis and retain their normal shape. EX: Immunizations are isotonic solutions so they do not damage the cells by gain or loss of water. EX: Immunizations are isotonic solutions so they do not damage the cells by gain or loss of water.

HYPOTONIC SOLUTIONS! Concentration of dissolved substances is lower in solution outside the cell than concentration inside the cell. Concentration of dissolved substances is lower in solution outside the cell than concentration inside the cell. There is more water outside the cell than inside. There is more water outside the cell than inside. Cells in hypotonic solutions experience osmosis in which water moves through membrane into cell. Cells in hypotonic solutions experience osmosis in which water moves through membrane into cell. EX: In animal cells, the pressure inside cell increases causing the cells to swell and sometimes burst! EX: In animal cells, the pressure inside cell increases causing the cells to swell and sometimes burst! EX: In plant cells, the rigid cell wall prevents bursting, but the cells become more firm. EX: In plant cells, the rigid cell wall prevents bursting, but the cells become more firm. CUCUMBERS IN THE MIST!

HYPERTONIC SOLUTIONS! Concentration of dissolved substances outside cell is higher than concentration inside cell. Concentration of dissolved substances outside cell is higher than concentration inside cell. There is more water inside cell than outside. There is more water inside cell than outside. Cells in hypertonic solutions experience osmosis in which water moves through membrane to outside of cell. Cells in hypertonic solutions experience osmosis in which water moves through membrane to outside of cell. Ex: In plant cells, membrane and cytoplasm shrink away from cell wall and plant wilts. Ex: In plant cells, membrane and cytoplasm shrink away from cell wall and plant wilts. EX: In animal cells, the pressure decreases and the cells shrivel. EX: In animal cells, the pressure decreases and the cells shrivel. Don’t be so SALTY!