Question

Even though cellular macromolecules contain a large number of carbon and hydrogen atoms, they are not all spontaneously converted into CO2 and H2O. This absence of spontaneous combustion is due to the fact that biological molecules are relatively __________ and an input of energy is required to reach lower energy states.

(A) large
(B) polar
(C) stable
(D) unstable

Answer 1

Biological macromolecules, which include numerous carbon and hydrogen atoms, do not naturally turn into CO2 and H2O because they are relatively stable, requiring energy to be converted.

Step-by-step explanation:

Certain cellular macromolecules such as proteins, nucleic acids (RNA and DNA), carbohydrates, and lipids do not spontaneously convert into CO2 and H2O because they are relatively stable, and an input of energy is required to reach lower energy states. Despite the high number of carbon and hydrogen atoms, these biological macromolecules need an energetic input for the bonds between these atoms to be broken and reassembled into carbon dioxide and water molecules through processes like cellular respiration.

These macromolecules are crucial for life and form the majority of a cell's dry mass. They are composed mainly of elements including carbon, hydrogen, oxygen, and nitrogen, and their stability is a result of carbon's unique properties, such as its ability to form four covalent bonds, creating complex structures that are not easily broken down without energy input.