Diffusion and Osmosis Bio 21L Spring 2003. Molecular Motion Molecules posses kinetic energy. Random motion Rotational, translation & vibration movements.

Slides:

Advertisements

Similar presentations

OSMOSIS Eve Oram.

Advertisements

Cellular Transport.

Movement IN and OUT of Cells Substances move in and out through the cell membrane Moving from high to low concentration DOES NOT REQUIRE ENERGY by the.

OSMOSIS OSMOSIS: The diffusion of water through a selectively permeable membrane SELECTIVELY PERMEABLE: some substances pass like water and others do.

Cell Environment Lab 5.

Lecture Diffusion, Osmosis and Osmotic Pressure.

Movement of materials through the cell membrane Passive Transport: materials move across the cell membrane by diffusion Diffusion can cause a cell to expand.

Movement of particles across the cell membrane without using energy

CHAPTER 2/ O’LEVEL BIOLOGY 5090 / GCE.

1 2 nd Law of Thermodynamics All things tend toward entropy (randomness). Molecules move (diffuse) from an area of high concentration to areas of low concentration.

OSMOSIS and DIFFUSION.

Solutions © 2009, Prentice-Hall, Inc. Osmosis Some substances form semipermeable membranes, allowing some smaller particles to pass through, but blocking.

Diffusion & Osmosis Ch 8. Diffusion Definition: Net movement of particles from an area of _______ concentration to an area of ______ concentration Example:

Tonicity Tonicity is a measure of the osmotic pressure (as defined by the water potential of the two solutions) of two solutions separated by a semipermeable.

Diffusion, osmosis and dialysis

Cell Boundaries and Movement. Cell Barriers Cell membranes – Structure: contain a flexible lipid bilayer with imbedded protein molecules and carbohydrate.

Transporting substances By Sangarun sangchachat Diffusion Diffusion is the movement of particles from an area of high concentration to an area of low.

Osmosis. 2 Diffusion of water across a membrane Diffusion of water across a membrane Moves from high water potential (low solute) to low water potential.

Cell Transport Osmosis and Diffusion.  Particles in constant motion  Run into each other and randomly spread out  Particles move from an area of high.

Chapter 4. Transport Across the Cell Membrane  Substances need to move into and out of the cell in order to maintain homeostasis  They can do this by.

Diffusion The movement of molecules from an area of high concentration to an area of low. concentration.

TRANSPORT THROUGH CELL MEMBRANES Diffusion and Osmosis.

OSMOSIS & TONICITY SEC 4.3 PG OSMOSIS: -a special case of diffusion involving water -water molecules move across a selectively permeable.

Osmotic, or Water Potential is simply a measure of the tendency for water to cross a selectively permeable membrane from low concentration to high concentration.

Diffusion and Osmosis. Passive Transport Passive transport- movement of molecules across a cell membrane without energy input Refresh: Solute Object being.

Unit 4, Lesson 2 Passive Transport. Passive Transport is the movement of molecules across a membrane that does not require energy No energy is required.

Movement of Materials Through The Cell Membrane For a cell to maintain its internal environment, (i.e., achieve homeostasis) it has to be selective in.

Passive Transport. Does not expend cellular energy for the movement to take place Ex-rolling down a hill.

Materials move across membranes because of concentration differences.

Lab 6 Diffusion/osmosis.

Passive transport - Does NOT need energy (diffusion, facilitated diffusion, osmosis)

Osmosis: the diffusion of water molecules through a selectively permeable membrane. Water moves from high to low concentration. Is the membrane permeable.

Tonicity is a measure of the osmotic pressure (as defined by the water potential of the two solutions) of two solutions separated by a semipermeable membrane.

Diffusion and Osmosis. Diffusion The passive movement of molecules or particles along a concentration gradient from areas of high concentration to low.

SECTION 3-4 How Things Get Into and Out of Cells

Cell Transport Chapter 7.3.

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

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

“Salad” Notes Movement of molecules in and out of the cell

Cell Membranes Osmosis and Diffusion

Membrane Structure and Function

Movement across the Plasma Membrane

Types of Transport Across Cell Membranes

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

Section Objectives Predict the movement of water and other molecules across selectively permeable membranes. (SPI ) Compare and contrast.

Cellular Physiology TRANSPORT.

Cellular Physiology TRANSPORT.

CELL TRANSPORT Cell membrane is semipermeable- allows certain things in, keeps certain things out Some molecules can pass right through small spaces in.

BIOLOGY Unit 2 Notes: Cell Membrane Transport

Cell Transport 7.3.

Movement of particles across the cell membrane without using energy

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

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

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

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

Cell Membranes Osmosis and Diffusion

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

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

CELLS Tonicity.

Solutions, and Movement of Molecules Therein

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

Movement Across the Membrane

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

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

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

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

Movement of particles across the cell membrane without using energy

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

Presentation transcript:

Diffusion and Osmosis Bio 21L Spring 2003

Molecular Motion Molecules posses kinetic energy. Random motion Rotational, translation & vibration movements Brownian Movement: random, zigzag movement, arising due to collisions of molecules with particles. BM is typical of colloids.

Diffusion Net movement of molecules from an area of high concentration to one of lower concentration Fick’s First law of Diffusion: Rate of diffusion is directly proportional to concentration

Osmosis Diffusion of molecules across a semi-permeable membrane from a place of higher concentration to one of lower concentration until the concentration on both sides is equal Osmolarity: Concentration of osmotically active particles Tonicity: The osmotic pressure/tension of a solution wrt blood Hypertonic solutions: osmotic pressure than the reference solution

Hypertonic solutions: higher osmotic pressure than the reference solution. Exosmosis Hypotonic: lower pressure than reference. Endosmosis Isotonic: the same osmotic pressure as reference; e.g. 0.9% NaCl Sol; 5% sucrose sol with human blood cells

Dialysis Separation of molecules based on size, using a semi-permeable membrane. Semi-permeable membranes: natural-cell membranes; synthetic- nitrocellulose memb. Factors affecting rate: Pore size of memb; Size of molecule; polarity of molecules; tonicity of solution outside dialysis bag

Water Potential ۴ & Uptake of Water by Plants Forces of adhesion & cohesion Evaporation & transpiration at leaf tip Generation of water potential Endosmosis into root cells Water uptake

Haemeolysis & Crenation: Ghost Studies Loss of water by cells- cell shrinkage or crenation In RBCs-leaves just membranes-used extensively to study memb structure In plant cells- cell shrinkage- allows plant cell memb to be seen Plasmolysis-rupturing plant cells by dunking in hypotonic solution. Turgid cell- plant cells that maintain a good osmolarity & tonicity- appear round & happy!

Cool! Let’s get started!