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1. How do cells move nutrients, products, and wastes in and out of the cell?
2. Why is this traffic across the membrane so important?
1.
Cellular Transport
How do cells move nutrients,
products and wastes in and out of
the cell?
Why is this traffic across the
membrane so important?
2.
Cells are filled and
surrounded by watery fluid.
This fluid helps
solids move
around inside,
outside the cell
and cross the cell
membrane.
3.
Cell Membrane
The cell membrane
controls what
moves in and out of
the cell.
4.
Semi-permeable membrane
Cell membranes only allow
some solutes (solids) to
move across it.
Movement across the
membrane depends on
size and type of the
solute (solid).
5.
Membranes are just so beautiful!!!!!
6.
Types of Transport
Low Down the
concentratio concentration
n gradient
High Up the
Low concentratio concentration
concentratio n gradient
n
7.
Summary: Types of
Transport
Passive Transport Active Transport
Molecules move from Molecules move from
area of high area of low
concentration to area concentration to area
of low concentration of high concentration
Movement is down the Movement is up the
concentration gradient concentration gradient
No energy needed Energy is required
Small molecules such (ATP)
as H2O, O2 and CO2 Large molecules, ions
8.
Diffusion – molecules move from area
of high concentration to area of low
concentration.
9.
Osmosis – water moves across
membranes (diffuses) to where there is less
water.
10.
Concentrations affect
Osmosis
Water
moves out
of the cell
Water
moves into
the cell
(in/out) at
equal rates.
11.
Red Blood Cells
in Hypertonic solution (video)
12.
Plants and Osmosis
Hypertonic solution (video)
13.
Concentrations affect
osmosis
higher amount of equal amount of lower amount of
solute outside solute in and out solute outside
cells of cells cells
14.
Solution is made of solutes
dissolved in a liquid or gas.
Let’s Review Hypertonic Solution = high
amount of solutes
Hypotonic Solution = low amount
of solutes
Isotonic Solution = equal amount
of solutes
Dynamic Equilibrium is reached
when solutes and water move
across a membrane at equal
rates because concentrations
are equal (isotonic).
Homeostasis = all living systems
need to maintain perfect
concentrations inside each cell
16.
Test your knowledge
On your left side, number 1-14 (short
answer)
15 and 16 Extended answers required
17.
1. Which side is A B A B
hypertonic? Lower Higher
concentration concentration Same concentration
of solute (sugar) of sugar of sugar
2. Why?
3. Can the solutes fit
across the membrane?
4. How can you describe
the membrane since it Selectively
permeable mem-
Water molecules
cluster around
is very selective about brane: sugar mole-
cules cannot pass
sugar molecules
what can move across?
through pores, but
water molecules can
More free water
Fewer free water
molecules (higher
molecules (lower
5. How can both sides concentration)
concentration)
reach equilibrium? Osmosis
Water moves from an area of higher
free water concentration to an area
of lower free water concentration
18.
ENVIRONMENT NaCL (salt is ionic,
10% NaCL cannot pass through
membrane without energy)
90% H2O
CELL ?
10% NaCL
90% H2O
6. What is the direction of water movement?
_________
7. Describe the solution outside the cell. ________
8. Describe the solution inside the cell. __________
19.
10% NaCL
90% H2O
CELL
?
20% NaCL
80% H2O
9. What is the direction of water movement?________
10. Describe the solution outside the cell. ________
11.Describe the solution inside the cell. __________
20.
15% NaCl
85% H2O
CELL ?
5% NaCl
95% H2O
12. What is the direction of water movement?_______
13. Describe the solution outside the cell. ________
14. Describe the solution inside the cell. __________
21.
15. How do cell move nutrients, products and wastes in
and out of the cell?
16. Why is this traffic across the membrane so
important?
22.
Demo Lab
Materials Procedure
- Celery sticks in
different salt
solutions???
- Iodine solution /
starch solution???
- Potato cores in
different salt
solutions???
23.
tendency of any molecule to spread out into available
Cell membrane space
Selectively permeable diffusion of a substance across a biological membrane
Hypotonic These help transport things across the membrane
lower concentration of solutes
passage of molecules and ions with transport proteins
Isotonic across a membrane down the concentration gradient
movement of a substance against its concentration
Passive transport gradient with the help of cellular energy
Diffusion Membrane only allows certain things across
Barrier made up of phospholipids and proteins that
Concentration gradient controls what enters and exits the cell
Solution When there are two different concentrations across a
membrane. Molecules always move from high to low
Solute concentration without energy (ATP)
equal concentrations of solutes
the diffusion of water across a selectively permeable
Active transport membrane
control of water balance
Membrane proteins
Combination of a solvent and a solute equally mixed
Molecule used in living systems for energy
Osmoregulation State where molecules move across the membrane at
equal rates
Facilitated Diffusion
A substance being dissolved in another
higher concentration of solutes
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