In respiration, from 180 gm of glucose 264 gm Co₂ + 108 gm H₂O + 686 Kcal energy is formed.

${\text{C}}_6{\text{H}}_{12}{\text{O}}_6+6{\text{O}}_2\to 6{\text{CO}}_2+6{\text{H}}_2\text{O}+686Kcal$

Atomic weight of C = 12, H = 1, O = 16

C₆H₁₂O₆  $=\left(13\times 6+12\times 1+16\times 6\right)$

                   = 180 gm

6CO₂         = 6 (12 + 16 x 2)

                    = 264 gm

6H₂O          = 6 (2 x 1 + 16)

                    = 108 gm

∴  From 1 molecule or 180 gm of glucose, through respiration, 264 gm CO₂, 108 gm H₂O and 686 Kcal energy are formed.