Arizona Esthetics State Board Practice Exam

What element is vital for the process of metabolism in living organisms?

1. Carbon

2. Nitrogen

3. Oxygen

4. Hydrogen

The correct answer is: Oxygen

Oxygen plays a crucial role in the metabolic processes of living organisms. It is essential for cellular respiration, a process that allows cells to convert nutrients into energy. During cellular respiration, oxygen is used to break down glucose and other organic molecules, facilitating the production of adenosine triphosphate (ATP), the primary energy currency of the cell. Without oxygen, many organisms cannot efficiently produce the energy they need, leading to anaerobic conditions that may not sufficiently support life or growth. While carbon, nitrogen, and hydrogen are also important elements that contribute to various aspects of metabolism—such as forming the backbone of organic molecules or being involved in protein synthesis—they do not have the same direct role in the energy production processes that oxygen does. Oxygen's unique ability to act as the final electron acceptor in the electron transport chain makes it indispensable for aerobic metabolism, which is necessary for the survival of many complex life forms.