• Active & Passive transport Comparison• Aim: How does “active” & “passive”

transport through a semi-permeable membrane occur?

• Objectives – Students should be able to:• 1-Define gradient, equilibrium, active &

passive transport, simple diffusion, osmosis, facilitated diffusion.

• 2-Explain the concept of simple diffusion, facilitated diffusion, osmosis, active & passive transport.

• Vocabulary development:• 1- Gradient = is the difference in measurement of two

different ends or side of a parameter.• 2- Equilibrium = is when the situation is stabled or

evenly balanced. It can be when there is no concentration gradient.

• 3- Passive transport = is the ability of a substance to travel from an area of high concentration (quantity) of that substance to an area of low concentration of that substance without applying energy.

• 4- Active transport = is the ability of a substance to travel from an area of low concentration (quantity) of that substance to an area of high concentration of that substance with applying energy.

• 5- Simple diffusion = is the ability of a substance to travel from an area of high concentration (quantity) of that substance to an area of low concentration of that substance without applying energy through a semi-permeable membrane without the help of an imbedded protein of the cell membrane. Example: Oxygen (O2) & carbon dioxide (CO2) at the alveolus of the lungs.

• 6- Osmosis = is the ability of water molecule(s) = H2O to travel from an area of high concentration (quantity) of water to an area of low concentration of water without applying energy through a semi – permeable membrane.

• 7- Facilitated diffusion = is a type of passive transport that can occur with the help of a “carrier protein” & “channel protein” imbedded through the semi-permeable membrane to transport substances to enter and leave the cell.

• 8- Semi-permeable membrane = is selective about the substance that can pass through a porous barrier or membrane.

• Facilitated diffusion is a type of passive transport that allows substances to cross membranes with the assistance of special transport proteins. Some molecules and ions such as glucose, sodium ions and chloride ions are unable to pass through the bilayer lipid cell membranes.

• Through the use of “ion channel proteins” and “carrier proteins” that are embedded in the cell membrane these substance can be transported into the cell. “Ion channel proteins” allow specific ions to pass through the protein channel. The “ion channels” are regulated by the cell and are either open or closed to control the passage of substances into the cell.

• Carrier proteins bind to specific molecules; both types of transport protein change shape and then deposit the molecules across the membrane. Once the transaction is complete the proteins return to their original position. • Use the Venn diagram to compare &

contrast passive transport of simple diffusion and facilitated diffusion.

• Active transport is the movement of a substance against its concentration gradient (from low to high concentration). In all cells, this is usually concerned with accumulating high concentrations of molecules that the cell needs, such as ions, glucose and amino acids. If the process uses chemical energy, such as adenosine triphosphate (ATP) on the “transport protein” embedded in the membrane it is called active transport.

• Active transport uses energy, unlike passive transport, which does not use any type of energy. Active transport is a good example of a process for which cells require energy. Specialized trans-membrane proteins recognize the substance and allows it access, expending energy on forcing it to cross the membrane when it otherwise would not, either because it is one to which the phospholipid bilayer of the membrane is impermeable or because it is moved in the direction of the concentration gradient.

• Write a sentence or more to explain & brainstorm with partner. • 1-In what direction are the substances

moving in a concentration gradient for active transport? Or why is it necessary to have active transport in a cell?• • 2-Explain what occurs to the “transport

protein” embedded in the membrane for active transport to occur?