Movement of materials
into and out of cells
Required materials and hormones enter.
Wastes and hormones targeted for other cells must
leave the cell that made them.
Circulatory system moves the materials throughout
animals.
Plasma membrane
• Made of phospholipids arranged in a bilayer
• The fatty acids tails are repelled by water and
point inward. The “phospho” ends like water
and point out.
Phospholipid Bilayer
What can cross the plasma membrane?
How do large, uncharged polar molecules
or ions pass into or out of a cell?
• The plasma membrane contains many
different kinds of molecules.
• Some of these are designed to move
materials in or out of a cell with out
contacting the phospholipid bilayer.
Plasma membrane details
Diffusion
• The movement of materials from an area of
higher concentration toward areas of lower
concentration. Movement continues until
there is an equal concentration everywhere.
Diffusion
Diffusion video
• https://www.youtube.com/watch?v=VY0mZU
DvbH4
Osmosis
• Osmosis is the movement of WATER from
areas of higher concentration to areas less
concentrated.
Water can enter or leave a cell. This depends
upon where the water is purest.
Osmosis
• https://www.youtube.com/watch?v=w3_8FSr
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Cystic Fibrosis
Facilitated Diffusion
• Many substances cannot pass through the
phospholipid bilayer. Impermeable
• Proteins embedded in the membrane create
pathways for specific things to pass. Selectively
permeable.
•
Favilitated Diffusion
Facilitated diffusion video
• https://www.youtube.com/watch?v=OV4PgZ
DRTQw
Active Transport
• Movement of materials from one area to
another. The result is an imbalance of
materials.
• The imbalance is a form of potential energy.
Yeast Cells
Boiled Yeast Cells
Active Transport
• https://www.youtube.com/watch?v=JGF6ry0
SWPs
Phagocytosis and Pinocytosis
• Can Move large quantities of material [not single
molecules] into or out of the cell.
• A materialis held inside a bubble called a
vacuole.The vacuole can fuse with a lysosome.
Chemicals from the lysosome digest what ever is in
the pocket.
• Undigested material is released when the
Pinocytosis
Phagocytosis
Exocytosis, releasing materials from a call.
Transporting O2 and CO2
Kidney
• The kidney controls the composition of blood.
• Removes wastes.
• Eliminates excess water.
• Balances pH and electrolytes.
• Controls blood pressure.
Location of Kidneys
Kidney Functions
• Filtration-size dependent, cells and large molecules
remain in the blood.
• Reabsorption-recapturing needed materials.
• Secretion-eliminating excess materials still in the
blood.
Nephron, functional unit of the kidney
How molecular composition of the blood is
controlled
• Osmosis, 100 liters of water leave the blood every day, 1
liter of urine is produced daily, 99 liters reabsorbed.
• Diffusion
• Facilitated Diffusion
• Active transport, reabsorption and secretion.