Yogurt

a) Bacteria-a terrifying species or an essential part of every day life? The answer is both! They are both potentially harmful and a life necessity. Bacteria are everywhere, but are typically too small to be seen by the naked eye. They are prokaryotes which means they are single celled with cell walls. There are many different shapes of bacteria. The three most common shapes are coccus,bacillus, and spirillum. Like all other life forms, bacteria require food(usually sugars). Bacteria uses enzymes to chemically ingest and break down the sugars into their molecules. Bacteria are crucial when it comes to making certain food products like yogurt. Yogurt can be produced when a specific kind of bacterica is added to milk. The mixture then begins to ferment . The bacteria takes in sugars from the milk and releases lactic acid.
b) The objective of this lab is to use a model to utilize Koch's postulates which involves making yogurt. This lab will be a controlled experiment using microbial techniques.
c) There will be four test tubes all containing milk. One of the tubes will have nothing added to it, therefore containing only plain milk. The other tubes will have yogurt, yogurt + ampicillin, and E.coli added to them. After inoculating the milk with the yogurt, we will need to check that the culture is the same.
d) The controls will be tube 1(milk) and tube 2(yogurt). Tube 1 is negative and tube 2 is positive which will verify the results of the lab.