What is the effect of nonsteroid hormones on cells?

Nonsteroid hormones exert their effects on cells by primarily activating second messengers. These hormones are typically water-soluble and cannot pass through the lipid bilayer of the cell membrane. Instead, they bind to specific receptors on the cell surface, triggering a cascade of intracellular events through the activation of second messenger systems, such as cyclic AMP (cAMP) or calcium ions.

Once the hormone binds to its receptor, it initiates a signal transduction pathway that amplifies the hormonal signal and leads to various biological responses within the cell. This can include changes in enzyme activity, regulation of gene expression, or alterations in cellular metabolism, among other functions. The use of second messengers is crucial for these hormones, as it allows them to exert their effects without needing to enter the cell directly.

The other options do not accurately reflect the mechanism of action of nonsteroid hormones. They do not change nuclear DNA directly since that requires specific interactions with steroid hormones, which do have the ability to pass through the cell membrane and bind to nuclear receptors. Nonsteroid hormones also do not work to store energy in cells or produce heat as their primary functions, though the metabolic changes they induce could indirectly influence energy utilization.