Yogurt Lab Discussion

a) In the first test tube, which was the negative control containing only milk, remained unchanged. In the second test tube, which was the positive control containing milk and yogurt, the texture appeared more like a thick liquid resembling yogurt. It also smelled like yogurt, and so I conclude that the bacteria from the added yogurt affected the milk and turned the whole mixture into yogurt. In the third test tube, which contained the ampicillin and yogurt, the state of the mixture was liquid and smelled like milk. Since the ampicillin is an antibiotic, it must have fought off the bacteria from the yogurt and enabled it to turn into milk. The last test tube contained yogurt and E.coli. This would answer the question as to see if any type of bacteria would be able to produce yogurt. The texture was somewhat resembling to yogurt but the smell was anything but. E.coli is unable to produce yogurt.
b)One possible error that could have occurred could be that the vortex was not properly used and the mixtures in the test tubes were not fully mixed causing complications that would later affect the results.