Bellwork1. What is concentration? (NOT the kind where

you’re thinking really hard…)

2. Why is the orange juice you mix with water called “concentrate”?

3. Draw a picture showing the difference between the molecules in a LOW concentration solution vs a HIGH concentration solution

Egg Lab (In lab book)

Question: How does a cell react to being placed in different concentrations of salt or sugar solutions?

Hypothesis: (leave a blank space- we will come back to this)

Background Information• Cell Membrane is semi-permeable (lets some

thing in, keeps other things out)

• An unfertilized egg is one HUGE cell underneath the hard shell is a semi-permeable cell membrane

Concentration

• Concentration: How close together molecules are in a solution; (amount of solute in an amount of solvent)

• Which beaker has a higher concentration of food coloring?

• Solute- a substance (molecules) that gets dissolved

• Solvent- a fluid that other molecules dissolve in

• Solution- an even mixture of solute and solvent

Egg Lab (In lab book)

Question: How does a cell react to being placed in different concentrations of salt or sugar solutions?

Hypothesis: If, then, as measured by….

Procedures1. Place bowl on scale & zero out2. CAREFULLY add egg to bowl & weigh in grams.

Record.3. In beaker, prepare a ____% ________ solution. First

add ____mL _______, THEN add 200mL ___________

4. Stir solution until all solute is dissolved5. Label beaker with % solute & period# & group #6. Carefully place your egg in solution & leave

overnight in class bin7. Weigh egg again after it has soaked overnight

Procedure #3: Prepare a….

Procedure #3 continued….

5% = FIRST add 10mL (solute) THEN add 200 mL H2O10%= FIRST add 20mL (solute) THEN add 200 mL H2O25%= FIRST add 50mL (solute) THEN add 200 mL HOT H2O50%= FIRST add 100mL (solute) THEN add 200 mL HOT H2O

Lab Group 1 5% salt solutionLab Group 2 10% salt solutionLab Group 3 25% salt solutionLab Group 4 50% salt solution

Lab Group 5 5% sugar solutionLab Group 6 10% sugar solutionLab Group 7 25% sugar solutionLab Group 8 50% sugar solution

Data TableSolution Initial Weight Weight after 24

hrsChange in weight (weight after 24 hrs- initial weight)

Did something move INTO or OUT of the cell?

0% salt (control)

5% salt

10% salt

25% salt

50% salt

0% sugar (control)

5% sugar

10% sugar

25% sugar

50% sugar

Go to the Lab!

• Raise hand to be dismissed from lab & come record your day 1 data @ Ms. D’s computer

18 days until science fair data due

Closure- out loud with group

• Do you think the semi-permeable cell membrane lets salt and/or sugar pass through? Explain why or why not.

(salt breaks apart into Na+ and Cl- charged ions, and sugar-sucrose- is a large carbohydrate macromolecule)

• Predict what will happen to the 0% controls vs the 50% solutions