What specific substance is produced by the Wood Frog to prevent lethal intracellular ice formation?

Glucose

The ability of *Lithobates sylvaticus* to survive profound freezing episodes relies on a sophisticated chemical defense mechanism employed by the organism. When temperatures drop severely during hibernation, the Wood Frog initiates the production and accumulation of large quantities of glucose. This sugar molecule serves the essential function of a cryoprotectant. In biological systems, cryoprotectants work by lowering the freezing point of water and managing the water-ice equilibrium outside the cell. By increasing the concentration of solutes in the unfrozen liquid phase, glucose effectively inhibits the formation of sharp, destructive ice crystals within the intracellular space, which would otherwise cause irreparable damage to the cell structure.