Transcript osmosis

Hypertonic – more concentrated outside of cell.
Study the diagram below.
Which arrow shows the direction the solute molecules
would move to achieve homeostasis?
*remember osmosis will go in the direction from high
conc. to low conc.
Today you will review
Passive Transport
2. Osmosis
3. Osmosis within the 3 types
of solutions.
1.
Types of Cellular Transport

Passive Transport
cell doesn’t use energy
1. Diffusion
2. Facilitated Diffusion
3. Osmosis

Active Transport
cell does use energy
Weeee!!
!
high
low
This is
gonna
be hard
work!!
1. Protein Pumps (sodium-potassium)
2. Endocytosis
high
3. Exocytosis
low
3 Types of Passive Transport
1.
2.
3.
Diffusion – molecules move high to low.
Facilitative Diffusion – diffusion with
the help of transport proteins.
Osmosis – Water moves high to low.
Passive Transport:
1. Osmosis
 1.Osmosis:
diffusion of
water through a
selectively permeable
membrane.
 Water moves from high
to low concentrations.
•Water moves freely
through pores.
•Solute (green) too
large to move across.
Effects of Osmosis on Life
 Osmosis-
diffusion of water
through a selectively permeable
membrane.
 There are 3 types of solutions:
 Isotonic
 Hypertonic
 Hypotonic
Isotonic Solution
Solutions that contain the same
concentration of solutes as the cytoplasm
are called isotonic (or normal saline)
solutions.
 There is no net movement of water either
into or out of the cell.
 Cells maintain their normal shape.

WATCH VIDEO OF
BLOOD IN AN
ISOTONIC SOLUTION
Isotonic Solution
•
Osmosis
Animations for
isotonic,
hypertonic, and
hypotonic solutions
Isotonic: The concentration of solutes in the
external solution is equal to the concentration of
solutes inside the cell.
Result: Water moves equally in both directions and
the cell remains same size! (Dynamic Equilibrium)
Hypertonic Solution
A hypertonic solution is a solution that
contains more (hyper) solutes than the
cytoplasm of the cell.
 Has less water than the cell and
water moves out of the cell.
 The cells shrink.

WATCH VIDEO OF
NORMAL RBCs
SUBJECTED TO A
HYPERTONIC
SOLUTION
Hypertonic Solution
•
Osmosis
Animations for
isotonic,
hypertonic, and
hypotonic solutions
Hypertonic: The solution has a higher concentration
of solutes and a lower concentration of water than
inside the cell. (High solute; Low water)
shrinks
Result: Water moves from inside the cell into the
solution: Cell shrinks (Plasmolysis/crenation)!
Hypotonic Solution
A hypotonic solution contains less
solute (thus, more water) than the
cytoplasm of the cells.
 The water will move into the cells
resulting in the swelling and lysis of
the cells.

WATCH VIDEO OF
CRENATED RBCs
SUBJECTED TO A
HYPOTONIC
SOLUTION
Hypotonic Solution
•
Osmosis
Animations for
isotonic,
hypertonic, and
hypotonic solutions
Hypotonic: The solution has a lower concentration
of solutes and a higher concentration of water than
inside the cell. (Low solute; High water)
Result: Water moves from the solution to inside
the cell): Cell Swells and bursts open (cytolysis)!
Let’s take a closer look!
http://www.coolschool.ca/lor/BI12/unit
4/U04L06/rbc.html
What type of solution are these cells in?
A
Hypertonic
B
Isotonic
C
Hypotonic
Summary



What is osmosis?
Is osmosis considered passive or active
transport?
What are the 3 types of solutions involved
in osmosis?
○ 1.
○ 2.
○ 3.
How well did you do
today?
What is Osmosis?
A. The movement of molecules.
B. The movement of molecules from an area
of high concentration to low
concentration.
C. The movement of water from a low
concentration to a high concentration.
D. The movement of water from a high
concentration to a low concentration.