Connect! Who is this guy? Have you ever heard of osmosis before? What does it mean?
OSMOSIS Simply refers to the diffusion of water across a membrane, from high to low concentration
Note concentration of solute as compared to concentration of water…what is the relationship?
Osmosis of water depends on the amount of “stuff” (solute) dissolved in the water on each side of the membrane. *More solute, less water… *Less solute, more water… solute water Which way will the water diffuse?
“Tonic” refers to the amount of solute (salt) dissolved in the water, as compared to cytoplasm. Hypotonic Isotonic Hypertonic v
Effect of Different Solutions on Red Blood Cells
A plant cell doesn’t react in quite the same way as an animal cell bc it has a cell wall.
Chunk! Define diffusion. Does diffusion occur in living or non-living environments? Does diffusion require the cell to use ATP? Describe diffusion between a blood capillary and a lung alveolus. Where else in the body does diffusion occur? What type of substances can diffuse across the cell membrane, generally? Define osmosis. What is relationship btwn amount of solute and amt of water? What happens to red blood cells in isotonic solution? Hypotonic??? Hypertonic??? What happens to plant cells?
Why do these cells do this?
Active Transport Unlike diffusion, active transport requires energy (ATP). Substances move from an area of low to an area of high concentration.
Active transport is a lot like rolling boulder up a hill. The natural tendency is for the boulder to roll down the hill, just as the natural tendency of molecules is to equally distribute themselves on either side of a membrane. However, by spending some energy to push the boulder higher and higher, you have the potential to use the boulder to do useful work that would be impossible otherwise. The same is true for molecules.
Different Types of Active Transport *Ion pumps *Phagocytosis*Exocytosis
Proteins in the cell membrane act as carriers. Energy from ATP causes the proteins to change shape, which opens up one end of the protein after the other. This carries the large molecules into or out of the cell. Ion Pump
Sodium/potassium ion pump
Phagocytosis – when a cell engulfs a solid particle, by an indenting of the cell membrane
White Blood Cells engulf pathogens (germs).
Exocytosis – when a cell sends materials out of the cell by a vacuole fusing with the cell membrane INSIDE CELLOUTSIDE CELL
Organisms that live in fresh water have to constantly spend energy to pump out the water that flows in by osmosis.
Chunk! Define active transport. How is it different from passive transport? Give 3 types of active transport. Why is active transport like rolling a boulder up a hill? What does size have to do w/ A.T.? Name 3 substances that cross the membrane by A.T. What is phagocytosis? What human cells carry out phagocytosis? What is exocytosis? Where does the material to be secreted come from?
Identify and explain each type of transport. A. B. C.
Explain this analogy of active transport.
Explain this cartoon. Think of a caption!
Just for Fun…
Images photo - Active Transport - Ion pumps - student.ccbcmd.edu/.../images/sppump.gif 3 Types Large molecules - Boulder - Cartoon - Red Blood Cells - Osmosis animation - Osmosis animation - Contractile vacuoles - e001.gif&imgrefurl= qPQdHP0w1nDE=&h=300&w=300&sz=8&hl=en&start=2&itbs=1&tbnid=zWgKv816n22UwM:&tbnh=116&tbnw=11 6&prev=/images%3Fq%3Ddiffusion%2Banimation%26gbv%3D2%26hl%3Denhttp://people.eku.edu/ritchisong/osmosis3.gif Blood and plant cells - Exocytosis - Contractile vacuole - dtc.pima.edu/.../parameciummovie.gif Osmosis jones - url= 0fc2tN5Q=&h=224&w=160&sz=10&hl=en&start=14&itbs=1&tbnid=MqLHQRQV2hQ64M:&tbnh=108&tbnw=77&pre v=/images%3Fq%3Dosmosis%2Bjones%26gbv%3D2%26hl%3Den