Quiz
1. Name and define the process shown by the
denture cleanser experiment.
2. Name and define the process shown by the
carrot experiment.
3. Define the following words.
Semi-Permeable:
Passive Transport:
Active Transport:
Learning Goals
1d. Differentiate between active and passive
transport.
1e. Explain how large particles get into and out
of cells (endocytosis/excotytosis)
Active Transport
• Active Transport – moving small particles
• A process of transporting small particles
that requires the cell to use energy
• Usually involves the movement of particles
from an area of low concentration to an area
of high concentration.
Active Transport
.
Active Transport
• Specific proteins
move small molecules
from and area of
lower concentration
to higher
concentration.
• ATP - energy used
from mitochondria
Passive Transport
• Passive Transport – moving small particles
• Diffusion and osmosis are examples of passive
transport.
•
Small particles move from an area of high
concentration to an area of low concentration.
• Passive Transport is movement of particles across
a cell membrane without the use of energy by the
cell through channels made of protein.
• Ex: sugar, oxygen, carbon dioxide
What process is this? Explain.
Passive Transport
Transport
Concepts
Passive
vs.
Active
Passive – no energy
Active – needs energy
Endocytosis vs. Exocytosis
Exocytosis
(moving larger molecules outside the cell)
–
Exocytosis
• Exocytosis – moving large particles out of
the cell
• Exocytosis is an active-transport process
• A vesicle forms around a large particle
within the cell.
• The vesicle carries the particle to the cell
membrane.
• The vesicle fuses with the cell membrane
and releases the particle to the outside of the
cell.
OUTSIDE THE CELL
OUTSIDE THE CELL
OUTSIDE THE CELL
SOLUTE
CARRIER PROTEIN
CARRIER PROTEIN
CARRIER PROTEIN
SOLUTE
SOLUTE
CYTOPLASM
CYTOPLASM
CYTOPLASM
Endocytosis
(moving larger molecules inside the cell)
Endocytosis
• Endocytosis – moving LARGE particles
into the cell
• Endocytosis is an active-transport process.
• Cell surrounds a large particle, and encloses
the particle in a vesicle to bring the particle
into the cell
• Vesicles are sacs formed from pieces of cell
membrane.
• Ex: bringing in protein
OUTSIDE THE CELL
OUTSIDE THE CELL
OUTSIDE THE CELL
SOLUTE
CARRIER PROTEIN
CARRIER PROTEIN
CARRIER PROTEIN
SOLUTE
SOLUTE
CYTOPLASM
CYTOPLASM
CYTOPLASM
Cell Membrane AKA plasma membrane
• The cell membrane contains proteins,
lipids, and phospholipids.
• Some of the proteins and lipids control
the movement of materials into and out
of the cell. Some of the proteins form
passageways. Nutrients and water
move into the cell, and wastes move
out of the cell, through these protein
passageways.
Cell Membrane is made of
molecules called phospholipids
which consist of:
• 1. a hydrophilic (water loving) head
• 2. two hydrophobic (water hating) tails
• Phospholipids get their name because the group of
phosphate-bearing heads is combined with a fat, or
lipid, molecule. In water they orient themselves so
that their heads are exposed to the water and the
hydrophobic tails are away from water. They
cluster in a bilayer in which the tails of the
phospholipids interact with themselves and
exclude water, while the heads expose themselves
to water.