Which substance is necessary for the enzyme cellulose to degrade cellulose in wood?

The correct answer is Trichonympha, which is a genus of protozoans that live in the guts of herbivorous animals like termites. These organisms play a crucial role in breaking down cellulose, a complex carbohydrate found in plant cell walls, including wood.

Cellulose itself is the substrate that needs to be degraded, but it does not serve as an enzyme or cofactor. Instead, Trichonympha contains specific enzymes that can break down cellulose into simpler sugars that the host organism can utilize. This symbiotic relationship is essential in nature as it allows herbivores to derive energy from plant material that they otherwise couldn't digest on their own.

Water is also important in the degradation process, as many enzymatic reactions require moisture, but it is not a specific agent of degradation for cellulose. Glucose, while a product of cellulose breakdown, is not necessary for the enzyme activity itself. Thus, Trichonympha's role is central to the enzymatic activity that leads to cellulose degradation.