Category: My Classroom Material

Effect of Detergent on Gelatin

 

“How Good Is Your Enzymatic Detergent?

 

Introduction:
In nature there are enzymes called proteases that “digest” or degrade proteins. Some of these enzymes have been genetically engineered and added to our laundry detergents in the hope that they will “digest” the protein off of our clothing. Do they work? Do they assist in cleaning? In this experiment you can compare different detergents and their ability to “digest” protein.
What is gelatin? Gelatin consists of protein chains that are easily digested into their amino acid components. Gelatin is prepared from collagen, a protein found in animal tendons and skin and taken out during the meat rendering process. Boiling collagen reduces the  weight by about one-third and separates the protein strands by breaking bonds. When the boiled collagen is cooled, it does not revert back to collagen but sets to a gel we know as gelatin.

Purpose :
To test the effectiveness  of laundry detergent brands (and their enzymes) to digest protein (in the form of gelatin)

Prelab

Hypothesis:   ____________ will decompose more gelatin in millimeters than ______________.

Materials:
Gelatin in 4 test tubes  Wax Pencil/ Permanent marker
3 detergent brands
Distilled water
Test tube rack
Parafilm®
Ruler

Procedure:
Day 1
1. Pour 5 ml of melted gelatin into 4 test tubes. Let the gelatin solidify.
2. Make 10% solutions of the five non-liquid detergents selected for testing. (Mix 10 g of detergent in 90 mL of distilled water). Label the solutions carefully and note whether enzymes are listed as a component of each.
3. Mark the top level of the gelatin with a permanent marker. Add 15 drops of each detergent solution to the top surface of the hardened gelatin in a test
tube. To one tube add 15 drops of distilled water. Label carefully.
Day 2
4. After 24 hours examine the test tubes. Notice that the gelatin has been liquefied in some tubes.  Use a ruler to measure the depth of the liquefication. Measure from the mark where the hardened gelatin started down to where it is still hard. Measure to the nearest mm. Record.
Day 3
5. Measure the depth of liquefication again after 48 hours.

Data   1 data table, 1 graph (time vs. mm. liquefied)

Enzymes listed? Liquefied After 24 hours (mm.) Liquefied After 48 hours (mm.)
Distilled Water
Detergent 1 ?
Detergent 2 ?
Detergent 3 ?

 

Conclusion:

1. What is the job of enzymes?

 

2. Why do laundry detergents often contain enzymes?

 

3. Why was gelatin used in this lab?

 

4. How is gelatin made?

 

5.  Name each of the laundry detergents you used and describe the effect each one had on the gelatin.

 

 

 

6.  Did any of the laundry detergents contain enzymes? If so, which one(s)?

 

7. Was your original hypothesis correct? Explain.

 

 

Effect of Solutions on Cells

 Effect of  Solutions on Cells

What happens when cells are place in different kinds of solutions

Plant cells placed in a hypertonic solution will undergo plasmolysis, a condition where the plasma membrane pulls away from the cell wall as the cell shrinks. The cell wall is rigid and does not shrink. 

   The Elodea cells  have been placed in a 10% NaCl solution. The contents of the cells have been reduced to the spherical structures shown.  

 

 

   Normal Elodea cells

 

 

Animal cells placed in a hypertonic solution will undergo crenation, a condition where the cell shrivels up as it loses water. Red blood cells in a hypotonic solution will swell and burst or lyse.

                               

 

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DNA Quiz

DNA QUIZ QUESTIONS


1. What is the general name for chemicals like DNA and RNA
2. What general shape does the DNA molecule have?
3. List 4 differences between RNA and DNA
4. Describe the function of the mRNA in Protein Synthesis
5. What is the definition of a codon
6. What is the definition of an anti-codon
7. How many amino acids will result from the following strand of DNA?
A C G C C C A A A T A C
8. Name the two stages that make up protein synthesis
9. Where in the cell does replication take place?
10. Describe the function of the tRNA in Protein Synthesis?
11. Describe briefly the events that occur during transcription?
12. Name 2 common environmental mutagens
13. Describe briefly the events that occur during translation?
14. What is the definition of     a) translation       b) transcription
16. Define complementary base pairing and give an example?
17. Describe the function of the ribosome during protein synthesis
18. From a given strand of DNA. Show the results of Transcription or Replication
19. Make a drawing of DNA or RNA nucleotide and label the parts
20. Give 2 examples of     a) purines          b) pyrimidines
21. Name the 4 bases that make up DNA or RNA molecules
22. Describe how an environmental mutagen could cause a mutation
23. Describe briefly the events that occur during replication?
24. List 3 functions of DNA
25. Describe the function of the DNA in Protein Synthesis
26. What is the definition of a chromosomal mutation
27. What is the definition of a gene mutation
28. If the Nucleic acids are like ladders: What chemicals form the backbone of DNA or RNA molecules?
29. If the Nucleic acids are like ladders: What chemicals form the rungs of DNA or RNA molecule?
30. Briefly describe what occurs during Protein synthesis 

31. What is recombinanant DNA. Give two uses of recombinant DNA

 

DNA SUBJECTIVE QUESTIONS
1. Describe 2 differences between the following pairs of terms
a. codon and anti codon                  b. replication and transcription              c. RNA and DNA  

d. transcription and translation          e. chromosomal and gene mutation       f. mRNA and tRNA           

g. purine and pyrimidine                    h. complementary base pairing and joining of adjacent nucleotides
2. Describe complementary base pairing. Show an example. 

3. Explain the roles/function of the following during Protein Synthesis:
a. DNA in the nucleus       b. Transfer RNA (tRNA)            c. Messenger RNA (mRNA)             d. Ribosome
4. Name 2 environmental mutagens and describe how they could cause a mutation in an organism 

5. Explain the process of DNA replication 

6. Make a drawing of an RNA or DNA nucleotide and label the parts 

7. Compare DNA and RNA with respect to the following things:
a. shape         b. chemical makeup         c. function         d. abundance in the cell

8. Explain the process of translation

9. Explain the process of transcription

10. Describe in sequence, the process of protein synthesis. Include in your answer the names of the various steps, the organelles involved, and the names of the major molecules.

11. Describe how radiation or another such substance could cause mutations to occur. 

12. From a given strand of DNA be able to determine the sequence of mRNA codons, and the amino acid strand produced.

Egg Osmosis Sample 1 Lab

Osmosis through the Cell Membrane of an Egg

Introduction:
The cell or plasma membrane is made up of phospholipids and different types of proteins that move laterally. These include peripheral proteins, which are attached to the interior and exterior surface of the cell membrane. Integral proteins are embedded in the lipid bilayer. Attached to these integral proteins are carbohydrate chains. These carbohydrates may hold adjoining cells together, or act as sites where viruses or chemical messengers such as hormones can attach. Cell membranes are selectively permeable. They allow some substances to pass through, but not others. Small molecules that are usually nonpolar, such as oxygen, water, and carbon dioxide, easily move through the lipid bilayer. Larger molecules, such as glucose, the food for all living things, must seek aid from the carrier proteins in a process called facilitated diffusion. Facilitated diffusion is a process used for molecules that cannot diffuse rapidly through cell membranes. Integral proteins are used by calcium, potassium, and sodium ions to move through the cell membrane. The muscles and nerves use these ions.
Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration. This difference in the concentration of molecules across a space is called a concentration gradient. Diffusion is a type of passive transport, meaning it does not require energy input by the cell. This type of transport and osmosis are the two processes used in this lab. Osmosis is the process by which water molecules diffuse across a cell membrane from an area of higher concentration to an area of lower concentration. When the concentration of the solute is higher outside of the cell, it is known as a hypertonic solution. When the concentration of the solute is lower outside of the cell, it is known as a hypotonic solution.

Hypothesis:
The substance, syrup, which has a higher solute concentration than the interior of the eggs, will cause water to leave the eggs’ membrane; the other substance, distilled water, which has a lower solute concentration than the eggs’ interior, will cause liquid to enter the eggs’ membrane.

Materials:
The materials necessary for this lab are: two fresh eggs in their shells, a felt tip marker, 200mL graduated cylinder, five jars, clear Saran wrap, white vinegar, clear sugar syrup (Karo), distilled water, tap water, pencil, paper, eraser, computer, electronic scale, and a plastic tray.

Methods:
Day One: On day one, label the five jars, with the felt tip marker: one labeled vinegar, two labeled syrup, and two labeled distilled water. Also put the group number on each jar. Find the mass of each egg and record this information in the data table. Place the two eggs in the jar labeled vinegar. Add vinegar until both eggs are submerged by it. Cover the jar with the clear Saran wrap. Place the jar on the plastic tray and allow to set for 24 hours.

Day Two: On day two, observe what has happened to your eggs. Record this in a data table. Now that the eggs’ shells are dissolved, gently remove the eggs from the vinegar. Rinse each egg with tap water. Pat the eggs dry with paper towels and mass them separately on the electronic balance. Record this in the data table. Place the eggs in the jars labeled syrup. Add syrup to each jar (labeled egg 1 or egg 2) until the eggs are submerged in syrup. Loosely cover each jar with Saran wrap. Place the jars on the tray and allow them to soak for 24 hours.

Day Three: On day three, observe what has happened to the eggs and record this information in the data table. Carefully remove the eggs from the syrup and rinse them with tap water. Pat dry with paper towels. Using the electronic balance, find the mass of each egg separately and record these masses in the data table. Place the eggs in the jars labeled distilled water (labeled egg 1 and egg 2). Add distilled water to each jar until the eggs are covered. Cover the jars with the Saran wrap and allow them to sit on the tray for 24 hours.

Day Four: On day four, remove the eggs from the jars and record the eggs’ appearance. Mass each egg on the electronic balance. Record this in the data table. Dispose of the eggs in the container provided by the teacher.

Results:

Egg 1 Data Table

 

Substance egg submerged in Egg’s mass before placed in substance Egg’s mass after removed from substance Observations of egg before placed in solution Observations of egg after removed from substance
Vinegar 59.2 g 86.0 g The egg’s shell is intact and is included in the first mass. The egg’s shell dissolved and wasn’t included in the 2nd mass.
Syrup 86.0 g 53.2 g The egg is swollen and soft, yet firm to touch. The liquid inside the egg diffused into the syrup.
Distilled Water 53.2 g 86.5 g The egg has lost some of its firmness. The water diffused into the egg, increasing the egg’s mass.

 

Egg 2 Data Table

 

Substance egg submerged in Egg’s mass before place in substance Egg’s mass after removed from substance Observations of egg before placed in solution Observations of egg after removed from substance
Vinegar 58.8 g 85.6 g The egg’s shell is intact and is included in the first mass. The egg’s shell is mostly dissolved and so wasn’t included in 2nd mass.
Syrup 85.6 g 52.2 g The egg is rough to touch and feels rather sturdy. The liquid inside the egg diffused into the syrup.
Distilled Water 52.2 g 88.9 g The egg feels more fragile and lighter in weight. The water diffused into the egg increasing the egg’s mass.

 

 

 

 

Egg in Hypotonic Solution of Vinegar & Plasmolyzed Egg in Distilled Water Egg in Hypertonic Solution of Syrup

 

1. When the egg was place in the water, in which direction did the water molecules move? The water moved into the eggs from the surrounding environment.

2. On what evidence do you base this? The eggs’ masses had increased from the time they were placed in the water to when the eggs were removed.

3. How do you explain the volume of liquid remaining when the egg was removed from the syrup? The volume of the liquid remaining when the egg was removed from the syrup must have increased because the eggs’ masses had decreased. The liquid within the eggs left the eggs and diffused into the surrounding syrup.

4. When the egg was place in the water after being removed from the syrup, in which direction did the water move? The water moved into the eggs.

Error Analysis:
Several errors may have occurred during this lab. When finding the eggs’ masses, on each occasion, an error may have occurred. Mistakes may have been made when recording these masses on the data table. Some of the eggs’ shell may have been left on the eggs’ membranes and changed the outcome of this lab. When the eggs were rinsed, after being placed in the vinegar and syrup, a small amount of water could have entered through the membranes of the eggs, effecting their masses. These are just a few of the errors that may have taken place throughout the lab.

Discussion and Conclusion:
The hypothesis was correct. When the eggs were placed in the syrup, their masses decreased greatly. This shows that the interior of the eggs must have had a lower solute concentration than their surrounding environment of syrup. The water within the eggs left through the membrane and diffused into the syrup, decreasing its solute concentration. When the eggs were placed in the distilled water, their masses greatly increased. This shows that the interior of the eggs must have had a higher solute concentration than their surrounding environment of distilled water. The distilled water diffused into the eggs’ membrane, decreasing the interior of the eggs’ solute concentration.

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