Question

Cellular respiration uses glucose and oxygen, which have high levels of energy, and releases CO₂ and water, which have low levels of free energy. Is cellular respiration spontaneous or not? Is it exergonic or endergonic? What happens to the energy released from glucose?

Short answer

Cellular respiration is a spontaneous process because it occurs without an input of energy.

It is an exergonic reaction because it releases energy from glucose molecules.

The energy released during cellular respiration is used to perform body activities such as muscle contraction.

Step-by-step solution

Cellular respiration is a spontaneous process

Reactions that occur without any requirement of energy from an outside source are called spontaneous reactions.Such reactions increase the entropy of the system. This means they are energetically favorable.

Cellular respiration is a spontaneous process because it occurs naturally in the absence of energy and increases entropy.

Cellular respiration is an exergonic reaction

The reactions that release free energy are called exergonic reactions. As energy is released during the exergonic reaction, these reactions occur spontaneously.

In cellular respiration, the reactants glucose and water have high free energy, whereas carbon dioxide and water have low free energy. So free energy is released during cellular respiration.

Thus, cellular respiration is a spontaneous and exergonic process.

Energy released in cellular respiration performs activities of the body

The breakdown of glucose using oxygen to produce carbon dioxide and water is cellular respiration. This process releases energy which is captured in the form of ATP (adenosine triphosphate).

The ATP molecules produced are used to perform energy-driven processes in the body, such as transport of ions across the membrane, muscle contraction, firing of neurons, substrate phosphorylation, etc.