Milk and Chemical Reactions free essay sample

Enzymes are biological catalyst. 2. Enzymes are proteins that catalyze chemical reactions. Emporase – an enzymes that speeds up the production of cheese. 3. First milk is pasteurized by heating it to 72? for 15 seconds to kill any harmful bacteria. Then, the milk is cooled and either a special blend of bacteria or an acidic solution such as vinegar or lemon juice is added. The milk is left for one and half hours while the bacteria converts lactose (a substance called milk sugar) into lactic acid. This causes the milk to sour and the pH to drop to approximately 4. 5. A substance called rennet is then added to the milk and within a short time, curds and whey are produced. Rennet is made up of a group of enzymes, such as pepsin and chymosin, that break up proteins. Rennet breaks up a milk protein, called casein, into paracasein. Paracasein combines with the calcium found in milk to form paracaseinate, which separates out. We will write a custom essay sample on Milk and Chemical Reactions or any similar topic specifically for you Do Not WasteYour Time HIRE WRITER Only 13.90 / page Milk fat and some water combines with paracaseinate to form curds. The remaining liquid is the whey. After curding, the whey is removed and the curds are processed into cheese. 4. Enzyme speed up chemical reaction by proving another pathway along which the reaction can occur this pathway has a lower ? G++ 5. Vinegar is an acidic liquid produced from the fermentation of ethanol in a process that yields its key ingredient. 6. Null (Ho): Enzymes speeds up chemical reactions. Alternative (H1): Enzymes don’t speeds up chemical reactions. 7. Null (Ho): Whole milk makes more cheese than 2% milk. Alternative (H1): Whole milk does not make more cheese than 2% milk. Methods (Procedure) 1. Obtain a blue and red cup. Label the blue cup â€Å"control treatment† and the red cup â€Å"experimental treatment†. 2. Add 100 ml of mild to each cup. Group A will use whole milk and group B will use skin milk 3. Using pH test strip, determine the pH of your milk (pH = 7) 4. Vinegar (pH =2) 5. Add 1 ml of vinegar to the control and experimental treatments and then determine the pH of the control (pH = 6) 6. Place the cups into the water bath set at 42C for 1 minute 7. Using a 10 ml Ctraduated add 1ml of emporse to the experimental treatment and stir. 8. Place the control and experimental treatments back into the water bath 9. After 10 min. observe both the control and the experimental treatments and record your observation 10. Using the mental stirrer, cut the curd (cheese) formed in the cup into a tic tac toe pattern, as shown in figure and refill it to the warm bath for another 5 minutes during this time. The curd will start to contract and release the whey 11. Weigh your cloth (3 grams) 12. Line a 250 ml beaker with cheese cloth as shown in figure 1b pour the contents of your experimental treatment into the beaker separating the curds and whey 13. After 5 minutes measure the volume of the whey (try to capture as much of the whey as possible) 14. Measure the pH of whey (ph=6) 15. Close the cheese cloth and tie it so that you can suspend it over a breaker for 24 hours (see figure 2) 16. After 24 hours, weigh your cheese and cheese cloth and determine the amount of cheese you made record your results. Result Discussion. It was raised to 42 C because the enzymes come from the cow’s stomach, where it is usually 40 degrees. This makes sure that the enzymes work better. It was done to create a better and more efficient environment. 2, Vinegar was added to make it the milk acidic. This is because the cow’s stomach is acidic and vinegar was added to recreate the atmosphere of the cow’s stomach. 3. Yes, enzymes do speed up chemical reactions. 4, Whole milk is better because whole milk has more fat than the 2% milk. This is enzyme break up the protein, which then combines with some water and paracaseinate. Therefore, whole milk is better. 5, Enzymes are not necessary for the making of cheese because the enzymes only speed up chemical reaction. Therefore, enzymes are not necessary but they are helpful because they make the process of making cheese faster. 6, I do not know how to make the experiment better because I was in isolation during the experiment. I learned that taking anti-biotic everyday is a very important thing because it helps you get better faster so that you do not have to miss lab experiments. Next time, I will be sure to ask Dr. Kilar for help when I miss class.