How micro-organisms help us to make drinks and baking?

What are micro-organisms?

Which micro-organisms are used to prepare antibiotics?

Are all micro-organisms of similar sizes?

Where do certain symbiotic micro organisms normally occur in human body?

Baking soda is used in small amount in making bread and cake. It helps to make this soft and spongy and aqua solution of baking soda turns red litmus blue. It is also used in Soda acid fire extinguisher. Use this information to answer the following questions How does baking soda help to make cakes and bread soft and spongy.