EVERYDAY SCIENCE

Detailed explanation-1: -Some types of bacteria are autotrophs. Most autotrophs use a process called photosynthesis to make their food. In photosynthesis, autotrophs use energy from the sun to convert water from the soil and carbon dioxide from the air into a nutrient called glucose.

Detailed explanation-2: -Bacteria can be both autotrophic and heterotrophic. Autotrophic bacteria such as Cyanobacteria and Rhodospirillum contain pigment-containing vesicles called ‘chromatophores’. These vesicles contain carotenoids and bacteriochlorophyll that help in photosynthesis.

Detailed explanation-3: -Heterotrophs are a group of microorganisms (yeast, moulds & bacteria) that use organic carbon as food (as opposed to autotrophs like algae that use sunlight) and are found in every type of water. Detecting heterotrophs in water is done by using a method called Heterotrophic Plate Count (HPC).

Detailed explanation-4: -Heterotrophic bacteria obtain carbon and energy for growth from naturally occurring organic compounds, while autotrophs use carbon dioxide as their main source of carbon. Autotrophs obtain energy from light (photoautotrophs) or the oxidation of inorganic compounds such as ammonia (chemoautotrophs).

Detailed explanation-5: -Photoautotrophs – or photosynthetic. They derive energy from sunlight. Chemoautotrophs – or chemosynthetic. They use chemical energy to prepare their food.