Cell Transport
Warm Up
 Why
is the enzyme-substrate relationship like
a lock & key model?
 Why
did we not detect glucose when we
added lactase to sucrose? (negative response)
Housekeeping
Macromolecules
and Enzymes Quest
next class
Macromolecules and Enzymes Review
Pages due next class
Understand the enzyme lab
BRING
YOUR LAPTOPS!
Recall organelles..
Where
What
is the cell membrane?
is the function of the
cell membrane?
Selectively permeable: Only lets certain
things through
Homeostasis
 Maintaining
stability/constancy (the same conditions)
 Regulating
movement of molecules from one side of
membrane to the other
Cell Transport

1. Passive Transport

A) Diffusion

B) Facilitated Diffusion

C) Osmosis

2. Active Transport
Passive Transport
 The
movement of materials across the cell
membrane without using energy
Diffusion
 The
process by which particles move from an
area of high concentration to an area of lower
concentration
Facilitated Diffusion
 When
molecules pass through special
protein channels
 It’s still diffusion – doesn’t require
energy!
Try It Yourself!
 With
your row, grab a beaker of water
 Place a drop of food coloring in the water
and observe. What happened?
 On
a piece of paper, draw a model (visual
PLUS caption) of what you think happened.
Use arrows & words.
Osmosis

The diffusion of water through a selectively
permeable membrane
Recall…the cell membrane is made of what?
 Lipid bilayer is hydrophobic.
But the cell membrane contains
aquaporins (water channel proteins)


High concentration Low concentration
Osmosis
Osmosis
 Isotonic:
Same amount of solute on both sides
of membrane
 Hypertonic:
Higher concentration (compared
to other side)
 Hypotonic:
other side)
Lower concentration (compared to
 Draw
a blood cell.
 The cell is in fresh water.
 Draw an arrow showing the direction in
which the water will move. Label with
appropriate terms (isotonic, hypertonic,
hypotonic)
NEXT CLASS
Macromolecules
and Enzymes Quest
next class
Macromolecules and Enzymes Review
Pages due next class
BRING
YOUR LAPTOPS!
Active Transport



The movement of materials against a concentration
gradient is known as active transport.
REQUIRES ENERGY.
Moves larger molecules
 1.
Exocytosis (out)
 2. Endocytosis (in)
Don’t let the liquids
touch!!