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Investigation:

Make your predictions in the spaces provided on your lab report.

Mark the eggs with pencil, and the four bowls, with the following labels:
Water, Vinegar, Vinegar and Salt, Vinegar and Sugar

In the mixing bowl, combine 2 teaspoons of food coloring with 2 cups of water and mix well. Pour ½ cup of this solution into each of the four bowls.

Add 1 tablespoon of vinegar to each of the three "vinegar" bowls.

Add 1 tablespoon of salt to the "salt" bowl, and add 1 tablespoon of sugar to the "sugar" bowl.

Stir each of the solution bowls until they are thoroughly mixed.

Use the spoons to lower each egg into its respective solution. Wait 10 minutes, then remove the eggs with the spoons.

Rinse each egg three times in the tub of water, then set the eggs someplace safe to dry. A paper towel or egg carton would do just fine.

Answer the set of summary questions on your lab report, and turn in the completed lab to your instructor.

Observations

Conditions

Observations

Water

The egg showed little or no change in color.

Vinegar

The egg changed to the color of the food coloring.

Vinegar and Salt

There was little or no change in the color of the egg.

Vinegar and Sugar

The egg changed to the color of the food coloring.

1. Which conditions caused the food coloring to form a compound on the surface of the egg? How could you tell?

2. When salt is added to the solution, it dissolves into its component ions. How did this seem to affect the compound formed on the egg shell?

3. In the vinegar and salt solution, is it possible there was some other compound that formed on the egg shell instead of the food coloring? Based on what you know about the charge on the egg shell and the ions in the solution, what might have reacted to form a compound on the shell instead of the food coloring?

4. What affect did the sugar have on the reaction of the food coloring with the egg shell, if any? Does this indicate anything to you about the charge of the sugar in the solution?

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Casey Durgan
Casey DurganLv2
28 Sep 2019

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Related questions

I need a good introduction and conlcusion of this experiment below is the expermeint and my results.

In this experiment you will observe the action of the enzyme amylase on starch. Amylase changes starch into a simpler form: the sugar maltose, which is soluble in water. Amylase is present in our saliva, and begins to act on the starch in our food while still in the mouth.

Exposure to heat or extreme pH (acid or base) will denature proteins. Enzymes, including amylase, are proteins. If denatured, an enzyme can no longer act as a catalyst for the reaction.

Benedict's solution is a test reagent that reacts positively with simple reducing sugars like maltose, but will not react with starch. A positive test is observed as the formation of a brownish-red cuprous oxide precipitate. A weaker positive test will be yellow to orange

PRE-LAB:

Add 1g of cornstarch to a beaker containing 100ml of cold distilled water. While stirring frequently, heat the mixture just until it begins to boil. Allow to cool.

PROCEDURE:

1. Fill the 250-mL beaker about 3/4 full of water and place on the hot plate for a boiling water bath. Keep the water JUST AT BOILING.

2. Mark 3 test tubes A, B and C. "Spit" between 1 and 2 mL of saliva into each test tube.

3. Into tube A, add 2 mL of vinegar. Into tubes B and C, add 2 mL of distilled water. Thump the tubes to mix.

4. Place tube B into the boiling water bath for 5 minutes. After the five minutes, remove from the bath, and place back into the test tube rack.

5. Add 5 mL of the starch solution to each tube and thump to mix. Allow the tubes to sit for 10 minutes, occasionally thumping the tubes to mix.

6. Add 5 mL of Benedict's solution to each tube and thump to mix. Place the tubes in the hot water bath. The reaction takes several minutes to begin.

OBSERVATIONS:

Tube A: Starch + saliva treated with vinegar (acid)

Was the test positive or negative? Negative

What does this indicate? The vinegar stops the action of amylase from catalyzing the starch therefore the solution becomes cloudier. This indicates that vinegar (acids) distort the shape of proteins in the salivary amylase.

Results: The solution turns cloudy.

Conclusion: Acids denature the shape of proteins in the salivary


Tube B: Starch + saliva and water, treated in a boiling water bath

Was the test positive or negative? Negative

What does this indicate? It indicates that when enzymes are exposed to extreme temperature for some time they are denatured and therefore become inactive.

Results: The benedict’s solution retained its color as the reaction did not occur. Extreme temperatures denatures enzymes, therefore when the salivary amylase was introduced to a hot water bath for five minutes the amylase was denture.

Conclusion: Salivary amylase/enzymes when introduced to hot temperatures it is a denatured therefore does not react on the substrate.


Tube C: Starch + saliva

Was the test positive or negative? Positive

What does this indicate? This indicates that the salivary amylase successfully worked on the starch.

Results: The benedict’s solution turned brown as an indication of the presence of sugar.

Conclusions: Salivary amylase acts on starch in favorable conditions, ie is optimum te

Please provide a lab report that explains your procedure, results and conclusions. Remember to include pictures of the lab set-up and results. Also, I want you to expand this initial experiment by proposing and testing (in the form of an additional experiment) a testable hypothesis that involves the above general concept. You will be graded on your use of the scientific method and the creativity/complexity of your experiment. Both the above experimentation and your original experiment may be included together into one experiment

Cell Membranes Lab Report

  1. Diffusion

  1. Compare the following terms: solvent, solute, andsolution.

  1. Go to Lab, Section I, Exercise 1 to explore the factorsinfluencing the rate of diffusion and complete the following:

  1. Predict how molecular mass and temperature may affect theoutcome of this experiment.

  1. Record the data from information in the Lab in the tablebelow.

Time

(min)

Diameter (mm)

5°C MB

5°C PP

23°CMB

23°C PP

0

15

30

45
  1. Construct a line graph of the data from the table above. Yourgraph should include labeled axes, units, and a legend indicatingwhich treatment is presented. Sign, date and prepare an image ofyour graph and include it with this lab report.
  1. Osmosis

  1. Go to Lab, Section II, Exercise 2 to view a demonstration ofosmosis and answer the following questions:

  1. Describe the net movement of water in osmometer 1.
  1. How is the movement of water molecules related to theconcentration gradient of the solution?

  1. Go to Lab, Section II, Exercise 3 to observe the effect ofsolute concentration on the rate of osmosis. Answer the followingquestions:

  1. Was the net movement of water in bags 1 to 4 into or out of thebags?
  1. Explain the results from bags 4 and 5.
  1. Selective Permeability of Membranes

  1. Go to Lab, Section III, Exercise 4 to learn about theimportance of selectively permeable membranes, then complete thetable and answer the following questions:

Contents of Beaker

0 Min

30 Min

Starch

Chloride ion
  1. Which substances diffused through the dialysis membrane?

  1. How does dialysis tubing model the selective permeability of aplasma membrane?
  1. Tonicity

  1. Go to Lab, Section IV, Exercise 5 and 6 to observe plasmolysisin Elodea cells and tonicity in red blood cells. Summarizethe concept of tonicity using blood and Elodea cells asexamples. Your description should incorporate these terms: turgid,plasmolysis, hemolysis, and crenation.

Cells

Isotonic Solution

Hypertonic Solution

Hypotonic Solution

Elodea

RBC

  1. Based on your previous work, reproduce the table below and drawan illustration of a single cell in each box. Include arrows toshow the direction of water flow relative to each cell and dots tosymbolize solutes. Sign, date and prepare an image of your drawingand include it with this lab report.

Cells

Isotonic Solution

Hypertonic Solution

Hypotonic Solution

Elodea

RBC

Summary Questions

  1. Compare diffusion and osmosis. Give an example of each.

2. In which direction will osmosisoccur if a 15% sugar solution is separated from a 25% sugarsolution by a selectively permeable membrane?

3. Why did osmosis, but not diffusionof sucrose molecules, occur across the dialysis membrane containing20% sucrose solution?

4. You are having a party and thecelery is limp. What might you do to make the celery crisp (turgid)again? What will occur in the cells?

5. A small amount of fertilizer(mineral salts) will stimulate plant growth, but over fertilizationcan kill plants? Why?

6. Michael adds sugar to his coffee.Explain what in this drink is the solvent, solute, and solution.

7. You add a cube of sugar to yourdrink. How could you speed up the diffusion of sugar moleculeswithout stirring?

8. How is dynamic equilibriumestablished within a solution?

Experiment 1 Fermentation by Yeast Experiment Inventory Labware (4) 250 mL Beakers (1) 100 mL Graduated Cylinder (1) Test Tube Rack (5) Fermentation Tubes = (10) Test Tubes (5 plastic and 5 glass; see Figure 4) (1) Measuring Spoon (4) Pipettes (1) Ruler Note: You must provide the materials listed in *red. EXPERIMENT 1: FERMENTATION BY YEAST Yeast cells produce ethanol, C2 H6 O, and carbon dioxide, CO2 , during alcoholic fermentation. In this experiment, you will measure the production of CO2 to determine the rate of fermentation in the presence of different carbohydrates with fermentation tubes. Note: Regular table sugar is sucrose, a disaccharide, which is made up of glucose and fructose. Glucose is a monosaccharide. Figure 4: Fermentation tubes. Note how the smaller, plastic test tube is inverted into the larger glass tube. You will create five fermentation tubes in this experiment. PROCEDURE 1. In this experiment, you will mix yeast with sugar, Equal®, and Splenda®. Before you begin, develop a hypothesis predicting what will happen when the sugar/sweeteners are mixed with yeast. Will fermentation occur? Why or why not? Record your hypothesis in the post-lab questions. 2. Use the permanent marker to label three 250 mL beakers as Equal®, Splenda®, and Sugar. 3. Empty the Equal®, Splenda®, and Sugar packets into the corresponding beakers. 4. Fill the Equal® and Splenda® beakers to the 100 mL mark with warm tap water. 5. Fill the Sugar beaker to the 200 mL mark with warm tap water. 6. Mix each beaker thoroughly by pipetting the solution up and down several times. Use a new pipette to mix each solution. Each beaker now contains a 1% solution. Set these aside for later use. 7. Completely fill one of the smaller plastic tubes with tap water and invert the larger glass tube over it. Push the small tube up into the larger tube until the top connects with the bottom of the inverted tube. Invert the fermentation tube (Figure 4) so that the larger tube is upright (there should be a small bubble at the top of the internal tube). Note: Repeat Step 7 several times as practice. Strive for the smallest bubble possible. When you feel comfortable with this technique, empty the test tube(s) and proceed to Step 8. CAUTION: Do not try to force the plastic test tube into the glass test tube. This might cause your glass test tube to break, causing you injury. If your plastic test tubes do not fit easily, please call eScience Labs for replacement glass tubes. If you are able to set up at least two fermentation tubes, continue with the experiment, but know that you will have to perform steps 12-15 in multiple steps. 8. Use the permanent marker to label the fourth 250 mL beaker as Yeast. 9. Fill this beaker with 175 mL of warm tap water. It should be between 30 and 40o C (warm to the touch). 10.Open the yeast package, and use the measuring spoon to measure and pour 1 tsp. yeast into the beaker. Pipette the solution up and down until all of the yeast is mixed homogenously into the solution. Note: Make sure the yeast solution remains homogenous before each test tube is filled in the proceeding steps. The yeast density is fairly high, and the yeast may settle to the bottom of the beaker if it rests for an extended period of time. 11. Use the permanent marker to label the big glass and small plastic test tubes as 1, 2, 3, 4, and 5. 12.Use the 100 mL graduated cylinder to measure and pour 15 mL of the following solutions into the corresponding small plastic test tubes: Tube 1: 1% Glucose Solution Tube 2: 1% Sucrose Solution Tube 3: 1% Equal® Solution Tube 4: 1% Splenda® Solution Tube 5: 1% Sugar Solution Note: Thoroughly rinse the graduated cylinder between each measurement. 13.Fill the remaining volume in each small tube to the top with the yeast solution. 14.Slide the corresponding larger tube over the small tube and invert it as practiced in Step 7. This will mix the yeast and sugar/sweetener solutions. 15.Place the fermentation tubes in the test tube rack, and use a ruler to measure (in millimeters) the initial air space in the rounded bottom of the internal tube. Record these values in the Table 1. 16.Allow the test tubes to sit in a warm place (approximately 30 °C) for two hours. Placement suggestions include: a sunny window sill, atop (not in!) a warm oven heated to approximately 85 °C (185 °F on an oven setting), or under a very bright (warm) light. 17.At the end of the fermentation period, use your ruler to measure (in millimeters) the final gas height (total air space) in each tube. Record this data in Table 1. 18.Calculate the difference between the initial and final gas height in each tube. Record this data in Table 1.

EXPERIMENT 1: FERMENTATION BY YEAST

Result Tables

Table 1: Yeast Fermentation Data

Tube

Initial Gas Height (mm)

Final Gas Height (mm)

Net Change (mm)

1

2

3

4

5

Post-Lab Questions

Include your hypothesis from Step 1 here. Be sure to include at least one piece of scientific reasoning in your hypothesis to support your predictions.

Did you notice a difference in the rate of respiration between the various sugars? Did the artificial sugar provide a good starting material for fermentation?

Was anaerobic fermentation occurring? How do you know (use scientific reasoning)?

If you observed respiration, identify the gas that was produced. Suggest two methods you could use for positively identifying this gas.

Hypothesize why some of the sugar or sweetener solutions were not metabolized, while others were. Research the chemical formula of Equal® and Splenda® and explain how it would affect yeast respiration.

How do the results of this experiment relate to the role yeast plays in baking?

What would you expect to see if the yeast cell metabolism slowed down? How could this be done?

Indicate sources of error and suggest improvement (for example, what types of controls could be added?).

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