H2O, or water, is often debated in the context of biomolecules. While traditional definitions of biomolecules typically emphasize carbon-based compounds found in biological systems, water plays a crucial role in cellular processes. It is integrated into biological systems and is essential for life, leading some to classify it as a biomolecule due to its active participation in these processes. Despite not being organic, water's significance in biological functions supports its consideration as a biomolecule in certain contexts.