Tuesday October 9, 2007

1 / 64

Tuesday October 9, 2007 - PowerPoint PPT Presentation

Tuesday October 9, 2007. Agenda: review scale for short assessment on 10/10 You need: pencil, lined sheet of paper, paper from back table To do: On a piece of paper… How do biological structures, such as cells, organelles, bacteria, and viruses, compare in size with one another?

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.

PowerPoint Slideshow about 'Tuesday October 9, 2007' - kacia

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Tuesday October 9, 2007
• Agenda: review scale for short assessment on 10/10
• You need: pencil, lined sheet of paper,

paper from back table

• To do: On a piece of paper…
• How do biological structures, such as cells, organelles, bacteria, and viruses, compare in size with one another?
• Order these objects, and give relative sizes (e.g. bacteria is 3x as big as a cell)
• Title this “Cellular Biology Notes” to be used for the rest of the unit
A scale is a series of ascending and descending steps to assess either some relative (column 3) or absolute (column 2) property of an object.
• In this case, the property being investigated is size.
Scientific Notation
• Number to Scientific Notation (Standard Form)a.) Move the decimal point to the right of the first nonzero digit. Count the number of places you moved the decimal point.b.) Multiply the number from step a.) times 10 raised to + or - the number of places you moved the decimal point. Use + if you moved the decimal to the left. Use - if you moved the decimal to the right.

47,800 4.78 × 1040.0000568 5.68 × 10-5

• Scientific Notation to Regular Notationa.) If the exponent on 10 is positive ("+"), move the decimal to the right the same number of places as the exponent. Add zeros as necessary.b.) If the exponents on 10 is negative("-"), move the decimal point to the left the same number of places as the exponent. Add zeros as necessary.

?

?

Wednesday
• Have them create their own tables, and then fill in xls in front of class
• Introduce students to directly visible cells- raw eggs soaked in vinegar overnight (24-48 hours) to remove their shells. Present students with a beaker of water, a beaker of highly concentrated sugar solution (light Karo corn syrup), and a beaker of raw egg whites. Ask students to consider their observations of the onion cells in concentrated salt solution from the PowerPoint and predict how the size of the egg cells would change in each of the three beakers.
Wednesday October 10, 2007
• Agenda: no HW
• You need: poster
• To do: quietly discuss how you will present your poster
How does SALT (salinity) affect cells in organisms?
• SALINITY = describes the amount of dissolved salts in water
• What happens to organisms in a HIGH SALINITY situation? LOW SALINITY?

This body of water is a dynamic ecosystem and is affected by the amount of rainfall received

1984

2004

Brainstorming
• What organisms are part of the ecosystem in the Great Salt Lake?
• What differences do you notice, if any, between the north and the south arm of the lake?
• Which half of the lake receives fresh water? How do you think this affects the lake?
• Why do you think the Great Salt Lake is a different color in the North end of the Lake?
Halobacterium
• Extremophiles
• “Salt-loving”: thrive in high saline conditions
• At low salt concentrations, water moves into the cell, causing it to expand
• If difference is too great, cell will rupture
• Produce a pigment, bacteriorhodopsin
• Absorbs light to produce ATP
• Creates a reddish purple color

Effect of salinity on Halobacterium growth:

Visualization Based on Experimental Data

Effect of salinity on Halobacterium growth:

Visualization Based on Experimental Data

Effect of salinity on Halobacterium growth:

Visualization Based on Experimental Data

Effect of salinity on Halobacterium growth:

Visualization Based on Experimental Data

Effect of salinity on Halobacterium growth:

Visualization Based on Experimental Data

Effect of salinity on Halobacterium growth:

Visualization Based on Experimental Data

Effect of salinity on Halobacterium growth:

Visualization Based on Experimental Data

Effect of salinity on Halobacterium growth:

Visualization Based on Experimental Data

Effect of salinity on Halobacterium growth:

Visualization Based on Experimental Data

Effect of salinity on Halobacterium growth:

Visualization Based on Experimental Data

Effect of salinity on Halobacterium growth:

Visualization Based on Experimental Data

Formulate new hypotheses:

What is the effect of salinity on other species in this network

Formulate new hypotheses:

What is the effect of salinity on other species in this network

Formulate new hypotheses:

What is the effect of salinity on other species in this network

North arm

South arm

No Salt

Low Salt

High Salt

E.Coli grown in varying salinity conditions

No Salt

High Salt

Low Salt

Wednesday 11/26/08
• Agenda:
• Have a safe break!
• You need:
• Nothing
• To do: Wait for instructions.
“Birthday Log”
• Line up in birthday order
• Must be in a straight line!
• The kicker? NO TALKING or WRITING! Mouthing is almost cheating…
• You all must decide (without talking!) when you are finished, and we will double check to see if you are correct!
• If I catch you talking more than once, you will be taken out of the game
• No tattle-tailing!
Monday 12/01/08
• Agenda:
• No HW
• You need:
• Pen/pencil
• Notes
• To do: Sit in your new seats!

Penguins are nice fatty, meaty animals. If they are such good prey, why don’t polar bears eat them?

When two compartments of different solute concentration are separated by a semipermeable membrane…

Hypertonic: the compartment with higher solute concentration

Hypotonic: the compartment with lower solute concentration

Isotonic: the internal solute concentration equals the external solute concentration

Cell Membrane
• Malleable enclosure that surrounds the cytoplasm and organelles
• Thin membrane that surrounds and defines the boundaries of all living cells
• Hair = ~150 micrometers
• Membrane = 6-10 nanometers
• 1 micrometer = 1,000 nanometers
• Therefore, a strand of hair is about 15,000 times thicker than the cell membrane.
Consists of a double layer (bilayer) of phospholipids
• Amphipathic: contain both hydrophilic (water loving) and hydrophobic (water hating) regions

Hydrophilic

Hydrophobic

Membrane Proteins (3 kinds)
• Integral proteins
• Transmembrane: pass entirely through the lipid bilayer
• Peripheral proteins
• Located entirely outside of the bilayer (cytoplasmic or extracellular)
• Bonded to surface of bilayer
• Lipid-anchored
• Located outside, but are linked to a lipid molecule that is within the bilayer
Cell Membrane
• Extremely thin (6-10 nm)
• Very flexible
• Why might this be important?
• What functions can an animal cell perform that a plant cell cannot? (Plant cells have rigid cell walls)
• Phagocytosis video
3 beakers
• Karo syrup (hypertonic)
• Tap water (hypotonic)
• Egg whites (control)
• How do you think the de-shelled eggs will react to each of these solutions? What will happen to the size of each egg?
• Why do we dissolve off the shell for this demonstration?
Tuesday 12/02/08
• Agenda: Water Movement Investigation Worksheet due Mon. 10/15
• You need: pencil, notes
• To do:
• Answer the question: How does a concentrated solution on one side of a membrane affect the direction of the overall movement of water through the membrane?
3 beakers
• Karo syrup (hypertonic)
• Tap water (hypotonic)
• Egg whites (control)
• How do you think the de-shelled eggs will react to each of these solutions? What will happen to the size of each egg?
• Why did we dissolve off the shell for this demonstration?

Corn syrup (Karo light)

Egg whites

Water

More concentrated solution OUTSIDE cell

Less concentrated solution inside cell

More concentrated solution INSIDE cell

Less concentrated solution outside cell

Same concentration inside and outside of cell

(CONTROL)

Percent change in size of egg

_________

Percent change in size of egg

_________

Percent change in size of egg

_________

Was the overall direction of water movement towards or away from the side of the membrane with a more concentrated solution?

Egg in

corn syrup

Egg in corn syrup became smaller.

This means more water went out of the cell than came into the cell.

The corn syrup outside of the egg has a higher concentration of dissolved substances than inside the egg cell.

Therefore, water moved TOWARDS the side of the membrane with a more concentrated solution.

More concentrated solution OUTSIDE cell

Less concentrated solution inside cell

Percent change in size of egg

_________

Was the overall direction of water movement towards or away from the side of the membrane with a more concentrated solution?

Egg in

water

Egg in water became bigger.

This means more water came into the cell than went out of the cell.

The egg has a higher concentration of dissolved substances inside the cell than the water outside the egg cell.

Therefore, water moved TOWARDS the side of the membrane with a more concentrated solution.

More concentrated solution INSIDE cell

Less concentrated solution outside cell

Percent change in size of egg

_________

Cell Membrane
• Malleable enclosure that surrounds the cytoplasm and organelles
• Thin membrane that surrounds and defines the boundaries of all living cells
• Hair = ~150 micrometers
• Membrane = 6-10 nanometers
• 1 micrometer = 1,000 nanometers
• Therefore, a strand of hair is about 15,000 times thicker than the cell membrane.
Consists of a double layer (bilayer) of phospholipids
• Amphipathic: contain both hydrophilic (water loving) and hydrophobic (water hating) regions

Hydrophilic

Hydrophobic

Cell Membrane
• Extremely thin (6-10 nm)
• Very flexible
• Why might this be important?
• What functions can an animal cell perform that a plant cell cannot? (Plant cells have rigid cell walls)
• Phagocytosis video
Tuesday October 16, 2007
• Agenda: create data table for

experimental data due 10/17

• You need: pencil, lab experiment
• To do:
• Find a partner, sit with them
• Compare your experimental designs, use these to come to consensus of how to run the experiment
Design a controlled experiment to investigate how a concentrated solution on one side of a membrane affects the movement of water through the membrane.
Materials
• 2 pieces of dialysis tubing (~4-5inches)
• 4 pieces of string (~4-5 inches)
• 2 beakers (same size!)
• Water
• Concentrated sugar solution (Karo syrup)
Tuesday October 16, 2007
• Agenda:
• Turn in revised experiment write-up with conclusion (no discussion) due10/19
• Diffusion Notes sheet due 10/18
• You need: pencil, lab experiment,

Sheet from back table

• To do:
• If you have not done so, add a column in your data table for the “% change” of mass for each dialysis tube
• Weigh your samples, and calculate the % change