Which of the following is NOT considered a biochemical molecule of life?

Water is considered a crucial biochemical molecule of life because it plays a fundamental role in various biological processes, including serving as a solvent for biochemical reactions, participating in hydrolysis and dehydration synthesis reactions, and regulating temperature within organisms. Similarly, both proteins and lipids are essential macromolecules that constitute the building blocks of life, involved in structural, enzymatic, and metabolic functions.

On the other hand, while gases like oxygen and carbon dioxide are vital for certain biological functions, they do not constitute biochemical molecules in the same sense as proteins, lipids, and water. They do not form complex structures or participate in a wide variety of biological functions as the other options do. Therefore, gases are not categorized as fundamental biochemical molecules of life, making this choice the correct answer.