Question

In a short essay (about 100–150 words), discuss how prokaryotes and other members of hydrothermal vent communities transfer and transform energy.

Answer 1

All the organisms will get energy from nutrition. The prokaryotes show many different modes of nutrition for the energy. These are classified mainly into 4 groups basing on the source of energy and carbon. They are

1. Photoautotrophs: these organisms use sunlight as energy source and CO2 as carbon source. All photosynthetic prokaryotes, like cyanobacteria are photoautotrophs.

2. Chemoautotrophs: these organisms use inorganic molecules (H2S, NH2, Fe+2) as energy source and CO2 as carbon source. This type of nutrition is unique to certain prokaryotes like purple sulphur bacteria and the microbes which grow in hydrothermal vents Ex; Sulfolobus.

3. Photoheterotrophs: these organisms use sunlight as energy source and organic compounds as carbon source. This is also unique type of nutrition exhibited by extreme halophiles. Ex: Rhodobacter, Chloroflexus.

4. Chemoheterotrophs: these organisms use organic compounds as energy source and carbon source. Most of the prokaryotes which live as parasites show this type of nutrition.