respiratory substrates are organic molecules oxidized during cellular respiration to release energy for ATP synthesis
include carbohydrates (e.g., glucose), lipids (e.g., fatty acids), proteins (amino acids) and other compounds once preferred substrates are depleted
these substrates enter pathways such as glycolysis, β-oxidation and the citric acid cycle, generating reducing equivalents (NADH, FADH₂) for oxidative phosphorylation
the most common respiratory substrate is glucose, owing to its universal availability, ease of transport into cells and high ATP yield per unit oxygen consumed
Sourav Pan
