Transcript Active Transport vs. Passive Transport Passive Transport

Active
Transport
vs.
Passive
Transport
Passive Transport
Goes with the flow … with the gradient….
HIGH to LOW
NO Energy needed
• Concentration: amount of a particular substance in a given
volume
• concentration gradient when one area has a higher
concentration than another area does, a exists.
NO!!!! It’s too crowded…
get out!
• Equilibrium is a state in which a system remains unchanged over
time. A space is filled evenly, equilibrium is reached.
A
High to
low until
equilibrium
reached
B
• Passive transport movement across a membrane without
the use of energy (ATP).
1)Diffusion
Modes of Passive Transport
3) Osmosis
2) Facilitated
Diffusion
Cacaused by: temp, pressure, concentration
Only sm particles squeeze through
the diffusion of water …
through channel proteins
Types of Osmotic Solutions
• Isotonic
• Hypotonic
• Hypertonic
Isotonic
Same size
Plant Cell
Blood Cell
11,397x
Hypotonic
Swell… burst
Plant Cell
Blood Cell
13,000x
Hypertonic
shrivels
Plant Cell
Blood Cell
13,000x
• Some unicellular eukaryotes have contractile vacuoles,
which collect excess water inside the cell and force the
water out of the cell.
• Animal cells have neither cell walls nor contractile
vacuoles.
• Many animal cells can avoid swelling caused by osmosis
by actively removing solutes from the cytoplasm.
Active Transport
Against the gradient….
LOW to HIGH
Requires Energy … ATP
 3 sodium ions go OUT
 2 Potassium ions go IN
Is an impt carrier proteins in
animal cells
• prevents Na+ from
building up in the cell,
• thus preventing osmosis
into the cell.
(Na+/K+ ATPase Pump)
2) vessicles
1)sodium-potassium pump
Modes of Active Transport
Too big to
use carrier
proteins …
use these
sacs …
 Endocytosis takes stuff IN
 Exocytosis takes stuff
OUT
Sodium Potassium pump
Endocytosis/Exocytosis
Exocytosis … same
thing…just EXITS .
.er uh… takes it to
outside of cell