Question

Where food molecules come from originally and what happens to them so that organisms can use them for energy.

Answer 1

Answer:

(i) As most organisms depend on plants and other autotrophs for food and autotrophs depend on inorganic sources to make food, the source of all food molecules comes from inorganic compounds.

(ii) Inside an organism, digestion and respiration take place to convert the food to usable forms of energy, mostly ATP.

(iii) The organism digests food to molecules like fatty acids, amino acids, and glucose. After that, mitochondrion in each individual cell uses other means to further breakdown the molecules to produce ATP, the energy currency of the cell.