What term describes the chemicals that adjust and maintain activities in the body?

The term that best describes the chemicals that adjust and maintain various activities in the body is hormones. Hormones are chemical messengers produced by glands in the endocrine system and are released into the bloodstream. They play a vital role in regulating many physiological processes, such as metabolism, growth and development, tissue function, and mood regulation, among others. By binding to specific receptors on target cells, hormones convey important information and instructions that help maintain homeostasis within the body.

In contrast, enzymes are biological catalysts that speed up chemical reactions but do not primarily regulate activities across the body. Neurotransmitters, while also critical for communication within the nervous system, primarily facilitate signaling between neurons and are not used for systemic regulation like hormones. Proteins serve a wide array of functions in the body, including structural roles and enzymatic activity, but they do not specifically function as hormonal regulators.