Transcript Active Transport

Active Transport
Biology
Unit V - Regulation
Active Transport
• Molecules move UP the concentration
gradient
• Molecules move from an area of lower
concentration to an area of higher
concentration
• Requires energy (ATP)
Active Transport
• Thousands of proteins are
embedded in the cell's
lipid bilayer.
• These proteins do much
of the work in active
transport.
• They are positioned to
cross the membrane so
one part is on the inside of
the cell and one part is on
the outside.
Example of Active Transport
Active Transport
• Occurs a lot in neurons.
• The membrane proteins
are constantly pumping
ions in and out to get
the membrane of the
neuron ready to
transmit electrical
impulses.
Passive & Active Transport
DIFFUSION
Energy
ATP not required
requirements
OSMOSIS
ACTIVE TRANSPORT
ATP not required
ATP required
Distance of
travel
Solutes and gases- long
distances
Solvent (water)- short distances
Short distances
Speed of
process
Rapid in gases, slow in
solution
Slow process
Rapid process
Definition
Transport of gases or
dissolved substances
(solutes) in solution from a
region of high concentration
to a region of lower
concentration of the
transported substance.
Transport of a solvent (water)
through a semipermeable
membrane from a solution of
low solute concentration to a
solution of higher solute
concentration.
Transport of a substance
from lower to higher
concentration of that
substance, using energy
from the cell, through a
living cell membrane.
Examples
Uptake of oxygen by a cell
performing aerobic
respiration. Oxygen
continues to diffuse into the
cell as O2 is removed by
respiration.
The movement of water into
cells of a marine (salt water
adapted) animal placed in fresh
water. May eventually cause
cells to swell and burst.
Transport of glucose
against its concentration
gradient from the gut
lumen into the cells lining
the intestine.