Question

When making yogurt, bacteria and milk are mixed together and set in a warm area. The container is sealed and no gasses are allowed to enter the container. After 24 hours the container is opened, and there is still no gas. Upon tasting the mixture there is a tart flavor. What type of respiration were the bacteria most likely carrying out?

A.
photosynthesis

B.
alcoholic fermentation

C.
lactic acid fermentation

D.
aerobic cellular respiration

Answer 1

When making yogurt the tart flavor get in the end is more likely because the bacteria have carried out a type of respiration named lactic acid fermentation (option C).

Step-by-step explanation:

The process of obtaining yogurt from whole milk involves the association of the bacterial species Streptococcus and Lactobacillus. In order to carry out the lactic acid fermentation that produces yogurt, the bacteria act in a different way:

1. Streptococcus is in charge of removing the oxygen from the milk product.
2. Lactobacillus promotes the conversion of lactose sugar into lactic acid.

This fermentation process leads to the conversion of milk into a coagulated and tart flavor product.

Other options are not correct because:

A. Photosynthesis : is the process that occurs in plants to obtain chemical energy from sunlight.

B. Alcoholic fermentation: in this chemical process alcohol is obtained from the fermentation of a sugar.

D. Aerobic cellular respiration: does not involve fermentation, but the series of processes that convert glucose into energy.