Describe the nutritional modes of organisms based upon where they obtain carbon energy. Include an example of each. Solution Describe the nutritional modes of organisms based upon where they obtain carbon and energy. Almost all organisms on the earth need energy to do their work, and carbon to use in building their chemical structures. And these two (energy and carbon) has to be obtained from external sources, based on the way they obtain energy and carbon, organisms are broadly classified into four different groups. Classification Obtaining energy and carbon Examples Autotrophs Photoautotrophs They get energy from sunlight and will not depend on other organisms for carbon. Use CO2 as a carbon source. All photosynthetic prokaryotes Plants (eukaryotes) Chemoautotrophs These make use of inorganic chemicals as an energy source. For example, H2S, Fe2+ etc and CO2 will serve as a carbon source. Archaea living in hydrothermal vents. Heterotrophs Photoheterotrophs Use light as an energy source and will use organic molecules as a carbon source. These type of organisms are rare. Heliobacteria, non-sulfur bacteria, green non-sulfur bacteria etc Chemoheterotrophs Use organic molecules like sugars as an energy source. Use organic molecules like proteins, sugars, fats, nucleic acids, etc. as a carbon source. This type of nutrition is most common form of nutrition on Earth Most of the prokaryotes, protists, fungi, and animals Classification Obtaining energy and carbon Examples Autotrophs Photoautotrophs They get energy from sunlight and will not depend on other organisms for carbon. Use CO2 as a carbon source. All photosynthetic prokaryotes Plants (eukaryotes) Chemoautotrophs These make use of inorganic chemicals as an energy source. For example, H2S, Fe2+ etc and CO2 will serve as a carbon source. Archaea living in hydrothermal vents. Heterotrophs Photoheterotrophs Use light as an energy source and will use organic molecules as a carbon source. These type of organisms are rare. Heliobacteria, non-sulfur bacteria, green non-sulfur bacteria etc Chemoheterotrophs Use organic molecules like sugars as an energy source. Use organic molecules like proteins, sugars, fats, nucleic acids, etc. as a carbon source. This type of nutrition is most common form of nutrition on Earth Most of the prokaryotes, protists, fungi, and animals.

1. Describe the nutritional modes of organisms based upon where they obtain carbon energy.
Include an example of each.
Solution
Describe the nutritional modes of organisms based upon where they obtain carbon and energy.
Almost all organisms on the earth need energy to do their work, and carbon to use in building
their chemical structures. And these two (energy and carbon) has to be obtained from external
sources, based on the way they obtain energy and carbon, organisms are broadly classified into
four different groups.
Classification
Obtaining energy and carbon
Examples
Autotrophs
Photoautotrophs
They get energy from sunlight and will not depend on other organisms for carbon. Use CO2 as a
carbon source.
All photosynthetic prokaryotes
Plants (eukaryotes)
Chemoautotrophs
These make use of inorganic chemicals as an energy source. For example, H2S, Fe2+ etc and
CO2 will serve as a carbon source.
Archaea living in hydrothermal vents.
Heterotrophs
Photoheterotrophs
Use light as an energy source and will use organic molecules as a carbon source. These type of
organisms are rare.
Heliobacteria, non-sulfur bacteria, green non-sulfur bacteria etc
Chemoheterotrophs
Use organic molecules like sugars as an energy source.
Use organic molecules like proteins, sugars, fats, nucleic acids, etc. as a carbon source. This type
of nutrition is most common form of nutrition on Earth
Most of the prokaryotes, protists, fungi, and animals
Classification
Obtaining energy and carbon
Examples

2. Autotrophs
Photoautotrophs
They get energy from sunlight and will not depend on other organisms for carbon. Use CO2 as a
carbon source.
All photosynthetic prokaryotes
Plants (eukaryotes)
Chemoautotrophs
These make use of inorganic chemicals as an energy source. For example, H2S, Fe2+ etc and
CO2 will serve as a carbon source.
Archaea living in hydrothermal vents.
Heterotrophs
Photoheterotrophs
Use light as an energy source and will use organic molecules as a carbon source. These type of
organisms are rare.
Heliobacteria, non-sulfur bacteria, green non-sulfur bacteria etc
Chemoheterotrophs
Use organic molecules like sugars as an energy source.
Use organic molecules like proteins, sugars, fats, nucleic acids, etc. as a carbon source. This
type of nutrition is most common form of nutrition on Earth
Most of the prokaryotes, protists, fungi, and animals