active transport
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Transcript active transport
Cells, Cells, Cells
Active Transport
and
Passive Transport
Active Transport
Active transport is the movement of
solutes and molecules across the cell
membrane WITH the use of energy
(ATP – adenosine tri-phosphate) by the
molecule
Active Transport
There are different
types of active
transport that occurs
in cells:
Endocytosis –
the process of taking
material INTO the
cell by means of infoldings, or pockets,
of the cell membrane
Active Transport
Exocytosis – is the process of releasing
material from the cell by means of small
vesicles (bubble-like membranous structure)
Active Transport
Passive Transport
Passive transport is the movement
of solutes and molecules across the
cell membrane WITHOUT the use of
energy (ATP – adenosine triAlso includes
phosphate) by the molecule
facilitated
diffusion of
larger molecules
through a protein
channel
Passive Transport
Diffusion – the
movement of
substances from
an area of high
concentration to
areas of low
concentration
Examples of small molecules:
carbon dioxide, oxygen, small
non-polar molecules
Shows the random movement of
small molecules down (with) the
concentration gradient until
molecules are evenly dispersed
(in equilibrium)
Passive Transport
Facilitated
diffusion – the
movement of
substances with their
concentration
gradient (high to low
concentration)
through protein
channels in the cell
membrane
Passive Transport
Osmosis – the
movement of
water across a
semi-permeable
membrane from
an area of high
concentration to
an area of low
concentration
Passive Transport
a. Water moves
from hypotonic to
hypertonic
solutions
Passive Transport
b. Water moves in
equilibrium (equal
amounts) in both
directions across a
membrane with
isotonic solutions
Factors that affect the movement of substances
by passive transport include: temperature; size
of the molecule; whether molecule is a solid,
liquid, or gas; and concentration amount