Question

what is the main source of energy for cellular respiration?
a) atp
b) proteins
c) carbohydrates
d) fats

Explanation:

Cellular respiration primarily breaks down carbohydrates (most commonly glucose) to produce ATP, the usable energy currency of cells. ATP is the product, not the source. Proteins and fats are used only when carbohydrates are unavailable, making them secondary energy sources.

Answer:

c) Carbohydrates