Download Active and Passive Transport

Active and Passive Transport
Notes Outline
• I. Compare and Contrast
a) Passive
b) Active
• II. Passive Transport
a) Diffusion
b) Facilitated Diffusion
c) Osmosis
• III. Active Transport
• IV. Bulk Transport
a) Exocytosis
b) Endocytosis
1.
2.
Pinocytosis
Phagocytosis
I. Compare and Contrast
• Passive Transport
– Movement of molecules through the cell
membrane which does NOT require energy
• Active Transport
– Movement of molecules through cell membrane
which DOES require energy.
II. Passive Transport
a) Diffusion:
– Natural movement of molecules
from HIGH concentrations to LOW
concentrations
– Uses channel proteins
• Ex: gas exchange at the alveoli —
oxygen from air to blood, carbon
dioxide from blood to air.
b) Facilitated Diffusion:
– Movement of SPECIFIC molecules
using a SPECIFIC CARRIER
PROTEIN
II. Passive Transport
c) Osmosis:
– Example of diffusion
– Movement of WATER from
HIGH concentrations of
WATER to LOW concentrations
of WATER
II. Passive Transport
c) Osmosis:
– Solution concentrations
1. ISOtonic: cell has equal
amount of solutes as its
surroundings
2. HYPERtonic: cell has lower
concentration of solutes
than its surroundings
WATER LEAVES CELL
3. HYPOtonic: Cell has higher
concentration of solutes
than its surroundings
WATER ENTERS CELL
III. Active transport
• REQUIRES ENERGY = ATP
• Molecules move from LOW concentrations to
HIGH concentrations
• OR when a cell has to move large particles
into or out of the cell
– Sodium-Potassium Pump in nerve
cells
– Re-absorption of glucose, amino
acids, and salts in nephron of kidney
IV. Bulk Transport
• Examples of active
transport
a) Exocytosis: releasing
particles from the cell
– Ex: the golgi apparatus
packages mucous,
hormones, or other
proteins and then releases
the packages through the
plasma membrane
IV. Bulk Transport
b) Endocytosis: cell surrounds the substances
and then pulls them into the cell
1. Pinocytosis: take in small particles or fluid (Ex:
roots
2. Phagocytosis: take in large particles like bacteria
or other cells