Question

What are the different ways in which glucose is oxidised to provide energy in various organisms? Give one example of each.

Answer 1

Glucose can undergo oxidation either under aerobic conditions and anaerobic conditions -

(i) During aerobic respiration, glucose is oxidised to give carbon dioxide, water and energy.

$\mathrm{Glucose}\to \mathrm{Pyruvate}\to 6{\mathrm{CO}}_2+6{\mathrm{H}}_2\mathrm{O}+38\mathrm{ATP}$


(ii) During anaerobic respiration, glucose is oxidised to give ethanol, carbon dioxide and energy.

$\mathrm{Glucose}\to \mathrm{Pyruvate}\to 2{\mathrm{C}}_2{\mathrm{H}}_5\mathrm{OH}+{\mathrm{CO}}_2+2\mathrm{ATP}$

Anaerobic respiration occurs in human muscles and results in the breakdown of glucose to lactic acid and energy.

$\mathrm{Glucose}\to \mathrm{Pyruvate}\to 2\mathrm{Lactic}\mathrm{acid}+2\mathrm{ATP}$