Health Tech

What Are Hormones

Hormones are complex organic substances that regulate and control various biochemical processes, growth, development, and reproduction in living organisms. They are secreted by cells and glands. Since hormones typically act on cells or tissues located far from their site of origin, they are also referred to as ‘chemical messengers.’ Even minute quantities of hormones are highly potent. They can’t be stored long, so they are broken down and excreted after use. Both a deficiency and an excess of hormones can cause disruptions in living organisms. Due to the broad definition of a hormone (as a signaling molecule that exerts its effect at a distance from its production site), various types of molecules can be classified as hormones.

Substances that can be considered hormones include eicosanoids (such as prostaglandins and thromboxanes), steroids (such as estrogen and brassinosteroids), amino acid derivatives (such as epinephrine and auxin), proteins or peptides (such as insulin and CLE peptides), and gases (such as ethylene and nitric oxide).

Introduction

Both plants and animals possess their own specific hormones. Hormones found in plants are known as phytohormones or plant hormones. These complex organic compounds are synthesized in one part of the plant and translocated to other parts, where they control growth and biological processes and establish coordination among various organs. Plant hormones assist in regulating growth, development, cell division, seed germination, bud formation, adventitious root growth, fruit formation, the prevention of premature fruit and leaf drops, cambial activity, and various other biological processes within the plant. In animals, hormone secretion typically occurs via endocrine glands; these glands are well-developed in vertebrates. Hormones travel through the bloodstream to reach their target sites. They are generally proteinaceous, steroidal, or polypeptide in nature.

Hormones influence the activity of cells at their target sites. Their modes of action vary according to their chemical nature. Protein and polypeptide hormones bind to receptors on the cell surface, triggering chemical changes within the cytoplasm that result in the desired physiological response. Steroid hormones, however, cross the cell membrane to enter the cell; after binding to receptors in the cytoplasm, they move into the nucleus. Inside the nucleus, they interact directly with DNA to influence protein synthesis. Not all steroid hormone receptors are located in the cytoplasm; some are situated within the cell membrane itself.

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