pienmolekyylillä

Pienmolekyylillä, meaning "small molecule" in Finnish, refers to a chemical compound with a low molecular weight. Typically, these molecules are organic and have a molecular weight of less than 900 Daltons. The definition is somewhat arbitrary and can vary depending on the context, but it generally distinguishes them from larger biomolecules like proteins, nucleic acids, and complex carbohydrates.

Small molecules play a crucial role in biological systems. They include a vast array of substances such as amino acids, nucleotides, sugars, lipids, vitamins, and neurotransmitters. These compounds are involved in virtually every biological process, acting as building blocks, energy sources, signaling molecules, and catalysts. For example, glucose is a small molecule essential for cellular respiration, while adenosine triphosphate (ATP) is the primary energy currency of cells. Neurotransmitters like dopamine and serotonin are small molecules that transmit signals between nerve cells.

In pharmacology, the term "small molecule drug" is commonly used. These are drugs that exert their therapeutic effects by interacting with specific biological targets, often proteins, within the body. Many of the most widely used medications are small molecule drugs due to their ability to be synthesized, absorbed, distributed, metabolized, and excreted relatively easily. Their small size allows them to penetrate cell membranes and reach intracellular targets. Examples include aspirin, ibuprofen, and many antibiotics. The study and design of small molecules for therapeutic purposes is a major area of pharmaceutical research.