Download Day 3 Passive Transport.notebook

Day 3 Passive Transport.notebook
February 05, 2016
Factors Affecting Diffusion & Osmosis
­ In groups of 3, half the class will conduct factors affecting diffusion lab while the others are working on osmosis
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THE CELL
IN ACTION!
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Passive Transport
The net movement of a substance across a membrane from an area of high concentration to an area of low concentration. NO ENERGY REQUIRED!!
Simple Diffusion, Facilitated Diffusion & Osmosis are examples of Passive Transport 3
Day 3 Passive Transport.notebook
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DIFFUSION
1) Simple Diffusion is the movement of molecules from areas of high concentration to a reas of low concentration. (eg. Air freshener)
Allows molecules to directly diffuse through the membrane (eg. O2 & CO2) Before Diffusion
After Diffusion
There is a higher concentration of oxygen molecules outside the cell than inside the cell.
The concentration of O2 molecules is the same outside and inside the cell.
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rea.
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Diffusion
Touch the red divider to watch the dye diffuse and write your observations.
Observations:
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Diffusion in the Human Body
Write your prediction about what happens to oxygen as it diffuses through the body. Erase within the red circles for a hint.
Prediction:
Lungs
Capillary
Cell
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Diffusion
2) Facilitated diffusion uses proteins to assist with allowing molecules to cross the membrane (eg. Glucose)
A protein channel & carrier protein is a protein that allows the transport of specific substances across a cell membrane.
Remember that a protein is a biological macromolecule made up from a menu of 20 different amino acids (a simple organic compound containing both a carboxyl (—COOH) and an amino (—NH2) group) and that the sequence of those chains determines the specific shape and function of the protein. 7
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water on.
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Another example of passive transport is:
Osmosis
Tap the image to see osmosis at work. Write your observations. Observations:
s of 8
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Tea Demonstration
Observe the diffusion process in each beaker and describe what happens.
a) Does the filter paper of the teabag act as a selectively permeable membrane? Explain.
b) Explain how this illustrates Passive Transport.
c) How did the temperature of the water affect the diffusion of solutes in each of the three beakers? Water flows by osmosis into the tea bag. You can see this if I remove the tea bag from the beaker and squeeze it to see the water come out. The soluble chemicals within the tea leaves diffuse through the tea bag and into the water; this changes both the color and flavor of the water in the beaker. 9
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Effects of Osmosis
Cell membranes are completely permeable to water, therefore, the environment the cell is exposed to can have a dramatic effect on the cell.
The 3 environments are:
Isotonic
Hypertonic
Hypotonic
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Effects of Osmosis
ISOTONIC SOLUTION ­ are solutions that have equal solute concentrations, equilibrium has be en reached. When a cell is placed in this type of s olution, the water diffuses into and out of the cell at the same rate maintaining equilibrium
_____________________________________________.
SOLUTE : SOLVENT
I SO Perfect??
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Effects of Osmosis
HYPERTONIC SOLUTION ­ is one with a low amount of water outside the cell. Therefore there is a higher concentration of water in the cell than outside it. When a cell is placed in this type of solution, the water diffuses out of the cell
__________________________, causing the cell to shrivel
______________. This could lead to a condition
called CRENATION! HYPER skinny??
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Effects of Osmosis
HYPOTONIC SOLUTION ­ is one with a high amount of water outside the cell. When a cell is placed in this type of into the cell
solution, the water diffuses ______________________, swell and possibly explode
causing the cell to ________________________. This could lead to a condition called Hemolysis! HYPO ­ Hippo???
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Real Life Applications IV drips! (Infusion of liquid substances directly into a vein)
5% glucose, 0.9% salt ­ this is normal blood
IV fluids are commonly organized into three general categories: isotonic, hypotonic, and hypertonic. Providers typically order a solution based on the particular patient’s blood electrolyte values. All IV fluids must be administered carefully, but hypertonic solutions are particularly risky. These solutions pull fluid into the vascular space by osmosis, resulting in an increased vascular volume that can result in pulmonary edema, particularly in patients who have cardiac or renal disease.
Solutes SUCK . . . water in or out of cell
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Problem
Mrs. Nurse prepared three solutions of salt water (1%, 5%, 9%) and poured them into test­tubes marked A, B, C. She forgot to identify which concentration was in which test­tube. However, the students decided they could identify the solution by adding some blood cells to the test­tubes.
The students knew that blood cells have an internal salt concentration of about 5%. They also knew that blood cells are impermeable to salt. They added some blood to each test­tube. Later they removed one drop of blood from each test­tube and examined the blood cells under a microscope. The blood cells in tube A were greatly swollen, and many membrane had ruptures open. The blood cells in tube B were shriveled up like raisins. The blood cells in tube C had not changed.
Determine the percent concentration of the salt in tube A, B, and C and explain your answer.
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Activity
Collect data from Factors Affecting Diffusion
Factors Affecting Osmosis
Complete Questions
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ACTIVE TRANSPORT
­ the movement of substances across the cell membrance from an area of low to an area of high. Cell energy (ATP) is used to move particles through membrane.
Types of Active Transport
1) Carrier Proteins ­ using ATP to change their shape allowing particles to be moved against the gradient
You Tube Video
What are the main differences between passive and active transport?
Stop @ 4:12 Begin at 5:04
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MOVEMENT OF LARGE PARTICLES
2) Endocytosis ­ cell membrane folds around a substance bringing it into the cell.
There are two types:
a) PHAGOCYTOSIS ­ when the substance engulfs a large particle
ex. white blood cell 'eating' bacteria
b) PINOCYTOSIS ­ when the substance engulfed is a liquid
ex. fluids in solution
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MOVEMENT OF LARGE PARTICLES
3) Receptor Mediated Endocytosis , ­specific molecules bind to receptor in the membrane vesicle forms as the membrane sinks in, lysosome joins vesicle breaks down substance which now can diffuse into cytoplasm and empty receptor becomes part of the membrane again reusing receptors 20
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MOVEMENT OF LARGE PARTICLES
4) Exocytosis, the movement of unwanted materials out of the cell by pushing a vesicle to the cell surface.
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Activity
1) Passive & Active Transport Questions ­ Homework
2) Osmosis Lab ­ Potatoes Wednesday
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