9/26/2013
Cell transport
What are the two types of
cell transport?
• Active Transport
• Passive Transport
Cell Transport
What is passive transport?
• During passive transport, substances and
molecules move from an area of high
concentration to an area of low
concentration.
• Passive transport does not require any
direct input of energy.
Cell Transport
What is passive transport?
• Passive transport includes diffusion,
osmosis, and facilitated diffusion.
• Diffusion is the movement of substances
from an area of high concentration to an
area of low concentration, or down a
concentration gradient.
Biology
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9/26/2013
Cell Transport
What is passive transport?
• Passive transport includes diffusion,
osmosis, and facilitated diffusion.
• Osmosis is a type of diffusion involving
water.
• During osmosis, water moves across a
selectively permeable membrane.
Cell Transport
What is passive transport?
• Facilitated diffusion is a type of diffusion
during which proteins provide a channel
to help substances move across the cell
membrane
• Always from areas of high
concentration to areas of low
concentration
• Always without using any energy from
the cell.
Cell Transport
What is active transport?
• Active transport:
• requires energy to move materials
• Materials are moved against the
concentration gradient, from an area of
low concentration to an area of high
concentration.
Biology
2
9/26/2013
Cell Transport
What is active transport?
• In endocytosis, some materials are moved
into a cell via a vesicle that enters the
cytoplasm.
• In exocytosis, some materials are moved
out of a cell via a vesicle that fuses with
the cell membrane and opens on the
outside of the cell.
Biology
3