Cellular Transport

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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?

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Cells are filled and surrounded by watery fluid.
This fluid helps solids move around inside,
outside the cell and cross the cell membrane.
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Cell Membrane

• The cell membrane controls what moves in and out
  of the cell.

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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).

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Membranes are just so beautiful!!!!!
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Types of Transport
Down the concentration gradient
Low concentration
High concentration
Up the concentration gradient
High concentration
Low concentration
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Summary Types of Transport

• Passive Transport
• Molecules move from area of high concentration to
  area of low concentration
• Movement is down the concentration gradient
• No energy needed
• Small molecules such as H2O, O2 and CO2

• Active Transport
• Molecules move from area of low concentration to
  area of high concentration
• Movement is up the concentration gradient
• Energy is required (ATP)
• Large molecules, ions

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Diffusion molecules move from area of high
concentration to area of low concentration.
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Osmosis water moves across membranes (diffuses)
to where there is less water.
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Concentrations affect Osmosis
Water moves out of the cell
Water moves across membrane (in/out) at equal
rates.
Water moves into the cell
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Red Blood Cells in Hypertonic solution (video)
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Plants and OsmosisHypertonic solution (video)
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Concentrations affect osmosis
equal amount of solute in and out of cells
higher amount of solute outside cells
lower amount of solute outside cells
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Lets Review

• Solution is made of solutes dissolved in a liquid
  or gas.
• 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

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Test your knowledge

• On your left side, number 1-14 (short answer)
• 15 and 16 Extended answers required

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A
B
A
B

• 1. Which side is hypertonic?
• 2. Why?
• 3. Can the solutes fit across the membrane?
• 4. How can you describe the membrane since it is
  very selective about what can move across?
• 5. How can both sides reach equilibrium?

Osmosis
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ENVIRONMENT
NaCL (salt is ionic, cannot pass through membrane
without energy)
10 NaCL90 H2O
?
CELL
10 NaCL 90 H2O

1. What is the direction of water movement?_________
2. Describe the solution outside the cell. ________
3. Describe the solution inside the cell. __________

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10 NaCL90 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. __________
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15 NaCl85 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. __________
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1. How do cell move nutrients, products and wastes
   in and out of the cell?
2. Why is this traffic across the membrane so
   important?

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Demo Lab

• Materials
• Celery sticks in different salt solutions???
• Iodine solution / starch solution???
• Potato cores in different salt solutions???

• Procedure

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Cell membrane
Selectively permeable
Hypotonic
Hypertonic
Isotonic
Passive transport
Diffusion
Concentration gradient
Solution
Solute
Equilibrium/Homeostasis
Active transport
Membrane proteins
Osmosis
Osmoregulation
Facilitated Diffusion
ATP
tendency of any molecule to spread out into available space
diffusion of a substance across a biological membrane
These help transport things across the membrane
lower concentration of solutes
passage of molecules and ions with transport proteins across a membrane down the concentration gradient
movement of a substance against its concentration gradient with the help of cellular energy
Membrane only allows certain things across
Barrier made up of phospholipids and proteins that controls what enters and exits the cell
When there are two different concentrations across a membrane. Molecules always move from high to low concentration without energy (ATP)
equal concentrations of solutes
the diffusion of water across a selectively permeable membrane
control of water balance
Combination of a solvent and a solute equally mixed
Molecule used in living systems for energy
State where molecules move across the membrane at equal rates
A substance being dissolved in another
higher concentration of solutes