Transcript Facilitated Diffusion & active transport

Facilitated Diffusion & active
transport
Facilitated Diffusion
• Integral proteins
help molecules
through membrane.
• 3 characteristics
– No energy is used
– Specific
– May become
saturated
• Example: glucose
Hint: “integral” means a part of, integral
proteins go through the plasma membrane
(also called transmembrane proteins).
Perpherial proteins are only on the surface
of the membrane.)
Glucose molecules entering a cell
using facilitated diffusion.
Active Transport
• Need to move
molecules up a
concentration
gradient.
• Uses cellular
energy in from of
ATP.
Think: why does the
cell need to use energy
to pump the yellow
balls out? Think about
the concentration
gradient… is it moving
“uphill” or “downhill”?
Ions moving across membrane
by active transport.
Active Transport: Coupled Channels
• Molecule that is
needed in the cell
is moved through
protein with
another substance.
• Na diffuses back
into cell allowing
second molecule
through.
Coupled channel.
Hint: Find Na on your
periodic table – what is it?
Active Transport: Proton Pump
• Hydrogen ions (H+)
are actively pumped
out of a cell
• Diffusion causes H+
ions to return
through a protein.
• When H+ returns
ATP is produced.
• Chemiosmosis (part
of photosynthesis and
respiration)
Chemiosmosis.
Hint: take another look at your periodic table. What is a
hydrogen atom without an electron?
Endocytosis Vs Exocytosis
• Endocytosis:
• Cells form a vesicle
to move large solid
materials into the
cell.
• Exocytosis:
• Cells moving large
materials out of
the cell.
Hint: when have we
used the prefixes ‘endo’
and ‘exo’ before? Look
at our Latin roots.
Two types of endocytosis
• Phagocytosis
– Solid objects moved into the cell.
(“phago” mean to eat.)
• Pinocytosis:
– Liquids moved into the cell.
(“pino” means to drink)
Summary should be at least 4
sentences.
1. Name 3 features of facilitated diffusion.
2. Name 2 ways active transport is different
than passive transport.
3. How do cells get large objects inside?
What does Garfield have wrong about osmosis?