What is essential for the production of energy in cells?

Glucose is a primary source of energy for cells, particularly in vertebrates, where it undergoes a process known as glycolysis. During glycolysis, glucose is broken down into pyruvate, releasing energy that is used to produce adenosine triphosphate (ATP), which is the energy currency of the cell. This metabolic pathway is critical because it allows cells to efficiently convert carbohydrates into usable energy for various cellular functions, including growth, repair, and maintenance.

While other substances like fatty acids and amino acids can also produce energy, glucose is typically the most immediate and preferred energy source, especially for tissues that require quick energy, such as the brain and muscles during excise. Nucleotides primarily serve as the building blocks of DNA and RNA and are not directly involved in energy production. Therefore, glucose is essential for energy production, making it the correct answer.