Egg lab day 1

Demonstration & Vocabulary

In journal, make a title: ‘Diffusion Demonstration’ & draw the two flasks as shown below.

STARTFINISH

Vocabulary (in your Egg Lab Booklet, page 7)

• Solution: a mixture of two or more substances that are evenly distributed.

• Solute: the substance that gets dissolved in a liquid solution.

• Solvent: the substance that does the dissolving in a liquid solution.

Example

• In the ocean, the water is the solvent and the salt is the solute.

What is the solute and solvent in each example solution (write in journal):

Kool-Aid• Solvent: • Solute(s):

Hot Chocolate• Solvent: • Solute(s):

What is the solute and solvent in each example solution (write in journal):

Kool-Aid• Solvent: water• Solute(s): flavor, sugar

Hot Chocolate• Solvent: milk (or water)• Solute(s): chocolate flavor powder, sugar

Demonstration- part II

• Now draw the finish diagram and describe in words what happened from beginning to end

STARTFINISH

More Vocabulary

• Diffusion: the movement of substances from high concentrations to low concentrations until an equilibrium is reached. (CO2, O2)

• Osmosis: the diffusion of water (from high concentrations to lower concentrations) through a selectively permeable membrane (until an equilibrium is reached).

Egg lab day 2

Yeah…the shell is gone! Now we can get at the cell membrane.

Beaker A:

200 mL water

20 mL food color

Beaker B:

200 mL water

40 mL food color

• Make a title in your journal “Comparing Concentrations” and copy down the pictures and labels below.

Beaker A:

200 mL water

20 mL food color

Beaker B:

200 mL water

40 mL food color

Please answer the following questions in complete sentences.1. Which beaker has more water?2. Which beaker has more food color?3. Which beaker has a greater concentration of food color?4. Which beaker has a greater concentration of water?

More practice: please copy down the example below in your journal. Quick sketches are fine! Be sure to label with amounts of tea and sugar for each.

Cup A:

12 oz of tea

1 oz sugar

Cup B:

8 oz of tea

1 oz sugar

Finish Each:1. Cup _____ has more tea.2. Cup _____ has more sugar.3. Cup _____ has a greater concentration of sugar (solutes). 4. Cup _____ has a greater concentration of tea.

Cup A:

12 oz of tea

1 oz sugar

Cup B:

8 oz of tea

1 oz sugar

Name: ______________Formative Quiz:

Pitcher A:1 liter water100 mL lemon juice

1. Which pitcher has more water?2. Which pitcher has more lemon juice?3. Which pitcher has a higher concentration of lemon juice?4. Which pitcher has a high concentration of water?

Pitcher B:1 liter water200 mL lemon juice

Vocabulary Review

• Diffusion: the movement of substances from high concentrations to low concentrations until an equilibrium is reached. (CO2, O2)

• Osmosis: the diffusion of water (from high concentrations to lower concentrations) through a selectively permeable membrane (until an equilibrium is reached).

The red blood cells are very important to survival because they transport oxygen

from lungs to the cells of the various tissues (muscles, nerves, etc.). These blood cells

are transported in a fluid (serum) that has approximately the same salt content as sea water.

If someone were admitted to the hospital and was in need of an IV (intravenous fluids) why is it critical that the concentrations of solutes (i.e. salts) in the IV is similar to that in the blood stream?

1. What would happen to the blood cells if the IV were too salty?

2. What would happen to the blood cells if the IV was pure water (less salty than water)?

OSMOSIS AND BLOOD CELLS

Blood Cells in different solutionsDehydrated Cells: water leaves cells because the solution that cells are in is too salty.

Bloated Cells: water enters cells because the solution that cells are in is not salty enough.

Happy Cells: concentration of salts equal in and out of cells.

Why do sports drinks contain ‘electrolytes’ (salts) in addition to water and sugar?

Egg lab day 3

Conclusions

• For your Egg Lab, explain WHY the egg in pure water got bigger. Hint: remember only water can pass through the egg’s membrane.

The egg in pure water got bigger because:

• Since water is the only substance that can go the through the egg membrane, water entered the egg (the egg absorbed water)

• But WHY did water enter the egg?

But WHY did water enter the egg?

Water always moves from HIGH CONCENTRATIONS to LOW CONCENTRATIONS during osmosis. Since the concentration of water was highest outside the egg (pure water = 100 % water), water then enters the egg.

What happened to the egg placed in corn syrup?

Why did the egg in corn syrup get smaller(less mass)? Why did water leave the egg?

Corn syrup is about 25% water, the egg is about 90% water. Water always move from high concentration to low concentration…so water

diffused through the egg membrane and entered the corn syrup solution – OSMOSIS!

Finish conclusions – pages 5+6

after the Egg Lab

DefinitionsPassive Transport: Transportation of materials in and out of cells using diffusion or osmosis; does not require the cell to use energy.

Facilitated Diffusion: the diffusion of larger molecules through special channel proteins in the cell membrane.

Endocytosis Model: How do cells get really BIG molecules in or out of the cells?

Materials• Plastic Bag (cell membrane)• candy (large ‘food’ molecules)• String• Scissors

Problem: The bag at your table represents a cell membrane. The cell really wants the food molecules (candy), but they are too big to pass through the membrane.

Endocytosis Model: How do cells get really BIG molecules in or out of the cells?

Your job is to figure out a way for the cell to get the food molecules (candy), without ever exposing the inside of the cell to the outside world or without ever having an OPEN HOLE in the bag.

Remember that the cell is filled with cytoplasm (liquid). When getting the food molecules there should never be an opportunity for any cytoplasm liquid to escape. Good luck! The first group to successfully solve this problem gets an additional food molecule (candy)!

• Cell absorbs a large amount of material such as a glucose molecule.

• Cell releases a large amount of material such as waste or protein.

DefinitionsActive Transport: When energy is required to transport materials in or out of cells. When a cell uses energy to obtain or get rid of something it needs.

For example, it would take energy to move materials against diffusion.

DefinitionsExamples of Active Transport:Molecular Transport (Pumps): Protein molecules in the cell membrane act like pumps and work against the forces of diffusion. Examples: calcium, potassium, or sodium.

Endocytosis/Exocytosis: Large molecules can be transported when the cell ‘engulfs’ them (endocytosis). In reverse it is exocytosis.

Group Task: Complete the chart using your notes.

Type of Movement

Energy Required? Passive or Active Transport?

What type of particle is moved?

What part of the membrane is the particle moving through?

How does it work? Explain (show picture)

Diffusion

Osmosis

Facilitated Diffusion

Molecular Transport

Endocytosis

Exocytosis

Type of Movement

Energy Required? Passive or Active Transport?

What type of particle is moved?

What part of the membrane is the particle moving through?

How does it work? Explain

 Diffusion  

No energy needed.Passive Transport

O2CO2

Lipid bi-layer

Particles diffuse through the membrane until the concentrations in/out of the cell are balanced (equilibrium).

 Osmosis  

No energy needed.Passive Transport

H20 Lipid bi-layer

Water moves through the membrane until concentrations in/out of the cell are at equilibrium.

 Facilitated Diffusion  

No energy needed.Passive transport

Glucose, sodium, potassium, calcium

Protein channel

Particles move from high to low concentrations through the protein channel.

 Molecular Transport  

Energy needed.Active transport

Sodium, calcium, potassium

Protein pump

The cell uses energy to pump the particles against the concentration (from low to high!).

 Endocytosis   

Energy needed.Active transport

Large molecules or clumps of material such as glucose.

The whole membrane.

The particle(s) are too big to fit through the proteins or lipids so the cell membrane folds over the particles and then pinches off.

 Exocytosis  

Energy needed.Active transport

Large molecules, clumps of material such as waste or proteins.

The whole membrane

The membrane folds and pinches together to allow the particles to escape.

Cell size

Warm-upPlease write down the dimensions

of the two theaters below

• Theater A: capacity 200 people and 6 exits• Theater B: capacity 800 people 16 exits

• Scenario: you go to the theater or to the movies. You take the prime center seats to view the movie. It is a full house (all seats filled).

Warm-up

• Theater A: capacity 200 people and 6 exits• Theater B: capacity 800 people 16 exits

• Unfortunately, there is a fire and the theater needs to be evacuated. Which theater would you rather be in, if you were to find yourself in this unfortunate incident?

• Discuss as group and be prepared to report out. Explain you answer in your journal.

Summarize why ‘large surface area to volume ratios’ are an advantage for cells:

Summarize why ‘large surface area to volume ratios’ are an advantage for cells:

• Surface-area represents ______________ of cell, while volume represent contents of a cell. The membrane allow material to enter and exit (provide passage ways). Therefore, it is an advantage to have lots of ____________ in relation to the cell volume (or a large SA/V ratio) so that material can exit and enter _________, consequently ____________ cells are quicker at getting things in and out.

• Just like small theater analogy.