# What are organisms that use chemical substances as a source of energy?

Aug 8, 2018

Is this not ALL organisms?

#### Explanation:

Autotrophs (green plants for instance) use solar energy to fix carbon dioxide to make simple sugars..

$6 C {O}_{2} + 6 {H}_{2} O \stackrel{\Delta , \text{photosynthesis}}{\rightarrow} {C}_{6} {H}_{12} {O}_{6} + 6 {O}_{2} \uparrow$

Heterotrophs consume the sugar so produced...
in the process of respiration...

${C}_{6} {H}_{12} {O}_{6} + 6 {O}_{2} \rightarrow 6 C {O}_{2} + 6 {H}_{2} O + \Delta$

Is respiration the reverse of carbon fixation?