Plasma Membrane Transport

Plasma Membrane Transport : Plasma Membrane Transport Cells

Fluid Mosaic Model : Fluid Mosaic Model

Phospholipid : Phospholipid

Cholesterol -immobilizes phospholipids (makes membranes less fluid and stronger) : Cholesterol -immobilizes phospholipids (makes membranes less fluid and stronger)

Membrane Protein Functions : Membrane Protein Functions

Slide 6 :

Passive Transport : Passive Transport Requires no energy Occurs due to natural concentration gradient Molecules move from high concentration to low concentration (DOWN the gradient) 3 Types Diffusion Osmosis Faciliated Diffusion

Diffusion : Diffusion

Diffusion : Diffusion A.K.A. simple diffusion Movement of small molecules across a selectively permeable membrane from an area of HIGH concentration to an area of LOW concentration w/o the use of energy (DOWN the concentration gradient) e.g. O2, CO2, urea, & alcohol

Osmosis : Osmosis The diffusion of WATER across a selectively permeable membrane OSMOTIC PRESSURE The pressure exerted on plasma membranes in solution Isotonic solution Hypertonic solution Hypotonic solution

Water Potential : Water Potential The physical property predicting the direction in which water will flow, controlled by the solute concentration

Slide 12 : Water potentials (ψ) are a way of measuring the free-energy of water. Water will flow spontaneously from a high potential to a low potential, like a ball rolling down a hill. (ψ) = Greek letter psi

Slide 13 : Physical pressure due to air & the container

Slide 14 :

Cells in Isotonic Solution : Cells in Isotonic Solution

Isotonic Solutions : Isotonic Solutions If the concentration of solute (salt) is = on both sides, there will be no net movement of water "ISO" means the same

Cells in Hypertonic Solution : Cells in Hypertonic Solution

Hypertonic Solutions : Hypertonic Solutions More solute (salt) molecules outside the cell, which causes water to be sucked out of the cell. In plant cells, the central vacuole loses water and the cells shrink, causing plasmolysis resulting in the plant wilting. In animal cells, the cells also shrink. In both cases, the cell may die. This is why it is dangerous to drink sea water

Plasmolysis : Plasmolysis A phenomenon in plant cells in which the cytoplasm shrivels and the plasma membrane pulls away from the cell wall when the cell loses water to a hypertonic environment.

Cells in Hypotonic Solution : Cells in Hypotonic Solution

Hypotonic Solutions : Hypotonic Solutions There are less solute (salt) molecules outside the cell, since salt sucks, water will move into the cell. The cell will gain water and grow larger. In plant cells, the central vacuoles will fill and the plant becomes stiff and rigid, the cell wall keeps the plant from bursting In animal cells, the cell may be in danger of bursting, organelles called CONTRACTILE VACUOLES will pump water out of the cell to prevent this.

Slide 22 :

Osmotic Potential : Osmotic Potential The tendency of water to move across a selectively permeable membrane into a solution Determined by measuring the pressure required to stop the osmotic movement of water into the solution.

Slide 24 :

Osmosis Review : Osmosis Review

Facilitated DiffusionProtein Channel or Pore : Facilitated DiffusionProtein Channel or Pore

Facilitated DiffusionProtein Carrier : Facilitated DiffusionProtein Carrier

Slide 28 :

Active Transport : Active Transport Requires cell energy (ATP) to move molecules AGAINST the concentration gradient; from an area of LOW concentration to an area of HIGH concentration Sodium–Potassium pump (Exchange 3 sodium ions for 2 potassium ions) Hydrogen ion, or proton pump (Pump hydrogen ion against the concentration gradient)

Phosphorylation : Phosphorylation The addition of a phosphate (PO4) group (From ATP) to a protein or a small molecule This changes the protein shape

Active Transport (Uniport) : Active Transport (Uniport)

Active Transport Na-K Pump : Active Transport Na-K Pump

Na-K Pump Antiport : Na-K Pump Antiport

Slide 34 :

Glucose-Sodium Symport : Glucose-Sodium Symport

Slide 36 :

Proton (Hydrogen Ion) Pump : Proton (Hydrogen Ion) Pump

Bulk Media Transport : Bulk Media Transport Endocytosis – Vesicle is created from the invagination of the plasma membrane, which pinches off, bringing large molecules into the cell Pinocytosis – Cell drinking (endocytosis) Phagocytosis – Cell eating (endocytosis) Receptor Mediated Endocytosis – Substrate binds to receptor found on the plasma membrane to be brought into the cell Exocytosis – Vesicle binds to the plasma membrane releasing the contents outside of the cell

Endocytosis : Endocytosis

Pinocytosis : Pinocytosis

Phagocytosis : Phagocytosis

Receptor Mediated Endocytosis : Receptor Mediated Endocytosis

Exocytosis : Exocytosis