INTRODUCTION1: In this lab we made our own cheese using different methods, and chemicals to speed up the cheese making process, or slow it down. The purpose of this lab was to see what goes into food and how it can be made. We are also observing what curdling agents work the best and the fastest. 2: In this lab we had to change one part about the previous lab. We decide to double the amount of FPC to see if that would make the milk curdle any faster or slower. The purpose of this lab was to give us some freedom to see what we wanted to change and conduct our “own experiments”. 3: In this lab we wanted to see what macromolecules where in the cheese we made in class. We did this by taking certain chemicals and mixing them with the cheese. If the chemicals changes or didn't change to a certain color it either meant it was there or it was missing.
HYPOTHESIS1: I hypothesis that the curling agents fpc, and butter milk will work the fastest, if you put either of these agents in then I think it will work faster than water or ncb. 2: I hypothesis that the milk with double the amount of FPC will curdle the fastest. If you put 2 times the agent in then it should work faster. 3: I hypothesis that the cheese will have all 4 macromolecules we are testing. If you put the cheese in the chemical then you will get the color needed to prove the macromolecule is there. PROCEDURE1.Label four 6ml tubes with the type of curdling agent group member. 2. Use a large pipet to transfer 3 ml of milk into each of the 6ml tubes. 3. Use a small pipet and transfer the entire contents of the tubes of fermentation produced chymosin, natural bovine chymosin or buttermilk to the labeled tube containing the milk. For water, fill the small transfer pipet to the bottom of the bulb and add to the labeled tube containing the milk. 4. Cap the tubes and invert the tubes three times and then transfer to 37°C water bath or place at body temperature (armpit) for incubation. 5. Set a timer and check for curdling every 5 minutes, by gently inverting the tube and examining for curds. 6. Record the time (in minutes) when the milk begins to curdle (small or large lumps) or solidified. 7. If the milk had not curdled in 30 minutes, check for curdling every hour. 8. In a data table similar to the Data Table 1, record the time (in minutes) when the milk begins to curdle (small or large lumps) or solidify. 9. Upon return to the lab, during the next work period, determine the amount of curds produced by each treatment. 10. For each treatment, weigh a paper cone and record the empty cone weight. 11. Transfer the entire contents of a tube into a labeled filter paper cone over a suitable collection vessel. Once all liquid has drained through, dry the filter paper with curds overnight. 12. Weigh the dry cone with dry curds. Subtract the dry cone weight. Record the weight of the curds (in mg) by multiplying the mass in grams by 1000. 13. Repeat with each treatment. 14. Create a data table that reports the Rate of Curd Production (weight/time) by each Curdling Agent. 15. Create a bar graph that shows the Rate of Curd Production by each Curdling Agent.
Part 2
1.Label four 6ml tubes with the amount of FPC agent for 2 group members. 2. Use a large pipet to transfer 3 ml of milk into each of the 6ml tubes. 3. Use a small pipet and transfer the entire contents of the tubes of fermentation produced chymosin(FPC) and label the tubes with the amount. 4. Cap the tubes and invert the tubes three times and then transfer to 37°C water bath or place at body temperature (armpit) for incubation. 5. Set a timer and check for curdling every minute, by gently inverting the tube and examining for curds. 6. In a data table similar to the Data Table 1, record the time (in minutes) when the milk begins to curdle (small or large lumps) or solidify. 7. Upon return to the lab, during the next work period, determine the amount of curds produced by each treatment. 8. For each treatment, weigh a paper cone and record the empty cone weight. 9. Transfer the entire contents of a tube into a labeled filter paper cone over a suitable collection vessel. Once all liquid has drained through, dry the filter paper with curds overnight. 10. Weigh the dry cone with dry curds. Subtract the dry cone weight. Record the weight of the curds (in mg) by multiplying the mass in grams by 1000. 11. Repeat with each treatment. 12. Create a data table that reports the Rate of Curd Production (weight/time) by each Curdling Agent. 13. Create a bar graph that shows the Rate of Curd Production by each Curdling Agent.
Part 3
-Monosaccharide indicator test 1.Test for glucose: In a test tube, mix 2 ml of cheese solution with 2 ml of benedict’s solution. Heat for 2 minutes in boiling hot water bath (100 ml of water in a 250-ml beaker at 100 degrees C) record all color changes and the length of time for each color change to appear. -Polysaccharide test 2. Test for starch: In a test tube, mix 2 ml of well-mixed cheese solution with 0.25 ml of Lugol’s Iodine. Gently swirl to mix. DO NOT HEAT. record the color change. -Protein test 3. Test for protein: place 2 ml of cheese solution in test tube. Wearing goggles and gloves, add 0.5 ml of 10% NaOH and gently vortex to mix. Add 0.25 ml of 5% copper sulfate (CuSO4) and gently mix. The NaOH and CuSO4 mixture is called biuret reagent. Mix well. Record color change after 30 seconds. -Lipid test 4. Test for lipids): Sudan IV. add 6 microliters of Sudan IV to 2 ml of cheese sample. Gently mix, red is negative for lipid test orange is positive test.
DATACurdling AgentCurdling Time Weight of Cone and Curds Weight of Cone Weight of Curds Rate Chymosin FPC 5 minutes 4.69g 1.15g 3.54g 708 mg/m
Chymosin NCB 24 hours 2.94g 1.15g 1.79g 1.24mg/m
Buttermilk 24 hours 2.8g 1.15g 1.65g 1.14mg/m
Water 24 hours 2.36g 1.15g 1.22g .84 mg/m
Data pt.2Curdling agent Weight of cone and curds Weight of cone Weight of curdes Rate Curdling time
FPC 100ml 3.16g .75g 2.4g 204mg/m 10 min
FPC 200ml 3.15g .75g 2.41 482mg/m 4 min Data pt.3Standard Indicator used Description + controle Description - controle Prescense
Glucose Benedict's Solution yellow-dark red blue Yes
Starch Lugols Iodine Black Red No
Protein Biuret Reagent Purple Light blue Yes
Fat/Lipids Paper test/ sudan IV Orange Red Yes
ANALYSIS1: In the graphs and charts shown above there are the results for our lab. The curdling time was how long it took the milk to turn into cheese. FPC was definitely the fastest out off all of them because it only took the fastest out of all of them taking only 5 minutes to curdle and the others took 24 hours to curdle. This means that my hypothesis is partially correct, because the FPC was the fastest. We are not sure if buttermilk, or the other curdling agents was the second fastest because it did not curdle in the 2 hours class period. We had to leave them in the classroom over night and the next day all 3 had curdled. We are not sure when the other 3 curdled which is a problem because it means the rate of the the milligrams per minute, because we didn't know the amount of minutes it took for it to curdle. We just said it took 24 hours. One other error in this lab was the fact that we fermented the cheese in our armpit which probably caused the cheese to ferment at different rates because the temperature of the students could be different. For example a kid who is wearing a sweatshirt armpit is going to be much warmer that a kids who is wearing a tank top. This could have caused a change in how fast or slow the cheese curdled. It would be hard to fix the first problem unless you had people in your group take shifts through the night seeing when the cheese would curdle. You could also stay up possibly 24 hours seeing when the cheese would curdle, but this is unreasonable for a high school classroom. Also instead of putting the cheese in people's armpits we could put the test tubes in a controlled water bath or heater to insure that all the possible outside variables that could change the experiment wont. I do not think there is a need for further investigation in the lad, because the cheese was mad and we understand what agents work the fastest, and how cheese is made. 2: The FPC with twice the amount curled almost twice as fast as the one with less FPC. This means my hypothesis was correct because the one with more FPC curled faster. This means that in the more FPC you put in the faster it is to make cheese. All of the other data besides the curling time and the rate was within .01g of each other, meaning they both make the same kind of and amount of cheese. The rate of the 200ml FPC was about double the amount of the 100 ml FPC because all the other factors were relatively the same. This means that the more FPC you put in then the cheese will be made faster. On problem that occurred was when we fermented the cheese in are armpit which probably caused the cheese to ferment at different rates because the temperature of the students could be different. For example a kid who is wearing a sweatshirt armpit is going to be much warmer that a kids who is wearing a tank top. This could have caused a change in how fast or slow the cheese curdled. Instead of putting the cheese in people's armpits we could put the test tubes in a controlled water bath or heater to insure that all the possible outside variables that could change the experiment wont. 3: This shows us that the cheese we made had glucose, protein, and lipids. My hypothesis is incorrect because we only had 3 of the 4 macromolecules. Some errors that could have occurred are mismeasurements or unsanitary materials if we mislabeled the pipette tips. We could fix these problems and make the lab better by simply having more experience in the lab and with the materials used. We could further your investigation by testing other foods and seeing what macromolecules they have and compare it cheese. CONCLUSIONIn conclusion we found out that FPC was the fastest most effective curdling agent. We tested this by taking mike and four curdling agents (FPC,NCB,Buttermilk, and water) and putting them in are armpit to fertilize them. We checked on if the milk had curdled every five minutes to see which one was the fastest, and FPC curdled first. FPC curled in 5 minutes, and the other 3 curdling agents curls overnight so they took 24. This means FPC had the fastest rate too because it curled so fast. One other reason it had the fastest rate was because the FPC cheese also was the heaviest. This means that FPC is the most effective method for making cheese because you can get the most cheese in the quickest time. Water was one of the ones that took 24 hours to curd, and also had the lightest curds. This means that water would probably be the least effective way to make cheese because it takes a long time to make and you don't get that much cheese. 2: In this lab we found out that if you put more FPC in milk it will curdle faster. We found this out by taking 2 different measurements of FPC (100 ml and 200 ml) and fermenting them in are armpit to see which one would curdle faster. We checked the curdling process every minute to see which one would curdle that fastest. The one with more FPC curled faster. This means that in the more FPC you put in the faster it is to make cheese. All of the other data besides the curling time and the rate was within .01g of each other, meaning they both make the same kind of and amount of cheese. The rate of the 200ml FPC was about double the amount of the 100 ml FPC because all the other factors were relatively the same. This means that the more FPC you put in then the cheese will be made faster. So if you were making cheese you would want to add more FPC because it would be easier to make and you would get more cheese faster. 3: In this lab we found out that the cheese that we made had the macromolecules glucose, protein, and lipids. We did this by taking certain chemicals and mixing them with the cheese. If the chemicals changes or didn't change to a certain color it either meant it was there or it was missing. We know that it had glucose because when we put the cheese in the benedict solution we saw that the color turned to a darker red meaning glucose was present in the cheese. We found out that it did not have starch in it because the color of the iodine did not change and stayed red. We figured out that there was protean in the cheese because when we put it in the burit it turned purple. Lastly we know that the cheese had fat in it because the sudan turned into a orange color.
New Content
Macro-molecules: A molecule containing a very large number of atoms, such as a protein, nucleic acid, or synthetic polymer. The four main classes being carbohydrates, lipids, proteins, and nucleic acids. After making the cheese we checked to see what macro-molecules were present in the cheese corresponding to the agents. The understanding of what macro-molecules are were vital to this project because we needed to know what we were testing the cheese for. Protein: a macro-molecule; a class of nitrogenous organic compounds that consist of large molecules composed of one or more long chains of amino acids and are an essential part of all living organisms. Proteins were present in the cheese that we made because of the tests we ran to confirm them. Lipids/fats: Any of a class of organic compounds that are fatty acids or their derivatives and are insoluble in water but soluble in organic solvents. They include many natural oils, waxes, and steroids. Our cheese tested positive for lipids. Carbohydrates: a macro-molecule that provides energy for the cell; two types- monosaccharides and polysaccharides; monosaccharides give the cell energy while polysaccharides store the energy.
Reflection
On this lab I felt like we rushed throughout some steps and maybe didn't fully understand what was going on, or possibly went to fast and messed up citron parts of the lab. I also felt like there was a great lack of communication and understanding between some group mates. I did think we did a good job at using are resources and trying are best to get what we needed to get done with what we had. I also thought we did a good job at collaborating with other groups in oder to get the right information and check are results.