What is the role of bacteria in the making of yoghurt from milk?

1. to make alcohol
2. to make carbon dioxide
3. to make lactic acid
4. to make lactose coagulate

I think the answer is number 4, but i'm not so sure.

Bacteria eat, and the remains of lactose become lactic acid, and it is the acid which makes coagulate.

One can do add vinegar or lemon juice to make milk coagulate also.

Answer 3.

thanks

You're on the right track! The correct answer is actually option 3 - bacteria play a crucial role in making yoghurt by producing lactic acid.

To understand this better, let's delve into the process of yoghurt production. Yoghurt is made from milk, and it undergoes fermentation to transform into its final product. The fermentation is primarily carried out by two species of bacteria: Lactobacillus bulgaricus and Streptococcus thermophilus.

These bacteria are added to the milk and create an environment conducive to their growth through a process known as incubation. During this incubation period, the bacteria consume the lactose present in the milk and convert it into lactic acid through a metabolic process called fermentation.

Lactic acid is responsible for several crucial aspects of yoghurt formation. It gives yoghurt its characteristic tangy taste and helps to thicken the milk by causing the proteins within it to coagulate. This process of protein coagulation is what gives yoghurt its smooth and creamy texture.

So, while lactose coagulation is involved in the yoghurt-making process, it is primarily driven by the production of lactic acid by bacteria, making option 3 - to make lactic acid - the correct answer.