transport across membranes. comparing passive and active transport active transport cells and...
DESCRIPTION
Passive Transport Passive Transport: movement of molecules across a membrane from an area of high concentration to an area of low concentration. Passive Transport does not require energy. Three types: –Diffusion –Osmosis –Facilitated DiffusionTRANSCRIPT
Transport Across Membranes
Comparing Passive and Active Transport
Active Transport
Cells and Osmosis
Examples of Passive Transport
Passive Transport
Transport Across Membranes
Passive Transport• Passive Transport: movement of molecules
across a membrane from an area of high concentration to an area of low concentration.
• Passive Transport does not require energy.• Three types:
– Diffusion– Osmosis– Facilitated Diffusion
Examples of Passive Transport
1) Diffusion: the movement of any particle from high to low concentration.
Glue this picture beneath your definition, Label the areas of high and low concentration, then shade them two different colors.
2) Osmosis: the movement of water from high to low concentration.
Glue this picture beneath your definition, Label the areas of high and low concentration in each picture, then shade them two different colors.
Examples of Passive Transport
3) Facilitated Diffusion: movement of large molecules from high to low through transport proteins.
Glue this picture beneath your definition, Label and shade the areas of high and low concentration, and the transport (carrier) proteins.
Examples of Passive Transport
Cells and Osmosis
Hypotonic—water moves into the cell High Low. Therefore cell swells.
Isotonic—water moves in and out of cell because there is no concentration difference. Therefore cell does not change.
Hypertonic—water moves out of cell High Low. Therefore cell shrivels.
Cells and Osmosis• In animal cells, hypotonic conditions can
lead to lysis, cells bursting.• In plant cells, hypotonic conditions provide
the water pressure needed to support the cell wall.
• In plant and animal cells, hypertonic conditions cause cells to shrivel (this is why plants wilt when not watered).
Active Transport• Active transport: movement of molecules from
an area of low concentration to an area of high concentration.
• Active transport uses membrane proteins that require energy (ATP).
Glue down the picture, then label and shade:- Areas of high & low concentration- Membrane proteins- ATP
Active Transport• Endocytosis: uses lots of energy to move
particles inside the cell. • Exocytosis: uses lots of energy to move
particles outside the cell.Endocytosis
Exocytosis
Uses energy
No energy required
Osmosis DiffusionSemi-
permeable membrane
With a gradient High Low Low High Movement
of particlesFacilitated diffusion
Exocytosis Membrane protein
Against a gradient
Endocytosis ATP
Comparing Active & Passive Transport
• In the top portion of the flap, draw a Venn diagram. Label one circle Active Transport and the other Passive Transport.
• Place the words from the chart below into the appropriate places on the Venn diagram.
Comparing Active & Passive Transport
High
Low
Active Transport
Low to High
Uses Energy
Passive Transport
High to Low
No Energy