moving cellular material
DESCRIPTION
Moving Cellular Material. Chapter 2, Lesson 3. Membranes. Control the movement of materials in and out of cell. Semipermeable – only certain substances can pass through. There are many different ways for a substance to pass through the membrane. - PowerPoint PPT PresentationTRANSCRIPT
Moving Cellular Material
Chapter 2, Lesson 3
Membranes• Control the movement of materials in and out of
cell.– Semipermeable – only certain substances can pass
through.– There are many different ways for a substance to pass
through the membrane.• Process depends on the physical and chemical properties of
the substance.
Passive Transport• The movement of substances through a cell
membrane– No energy– Usually small molecules (O2 and CO2)
– Depends on the amount of substances on each side of the membrane.
Diffusion• The movement of substances from an area of
higher concentration to an area of lower concentration.
Passive Transport - Osmosis
The diffusion of water molecules through a selectively permeable membrane. (No energy required)
Red Blood Cells
Facilitated Diffusion
• When molecules pass through a cell membrane using special proteins called transport proteins.
Active TransportThe movement of materials through a cell membrane using energy. (Moves from low to high concentration)
Endocytosis
• The process during which a cell takes in a substance by surrounding it with the cell membrane.
Exocytosis
• The process during which a cell’s vesicles release their contents outside the cell.