Proteínu

Proteínu (the genitive form of proteín in Slovak and Czech) refers to the molecule commonly known as protein. Proteins are large, diverse biomolecules essential to nearly all biological processes. They are built from amino acids linked by peptide bonds and fold into unique three‑dimensional shapes that determine their function.

Proteins have a hierarchical structure. The primary structure is the linear sequence of amino acids. Local patterns form secondary structures, such as alpha helices and beta sheets. Further folding yields the tertiary structure, and some proteins assemble into quaternary structures containing multiple polypeptide chains. The final shape is stabilized by hydrogen bonds, disulfide bonds, hydrophobic interactions and ionic forces, and can be influenced by temperature, pH and solvent conditions.

Functions of proteins are wide-ranging. Enzymes act as catalysts to drive biochemical reactions. Structural proteins provide support and form tissues, such as collagen in connective tissue and keratin in hair and nails. Transport proteins carry molecules, including hemoglobin moving oxygen in the blood. Signaling proteins regulate cellular processes, while antibodies form part of the immune system. Motor proteins enable movement, and storage proteins reserve amino acids for later use.

Biogenesis and nutrition: In cells, proteins are synthesized on ribosomes through transcription and translation, with post‑translational modifications refining activity. Diet supplies amino acids; nine are essential for adults and must be obtained from food. Protein quality depends on the amino acid profile and digestibility, with both animal and plant sources contributing to a balanced intake. Abnormal protein levels or misfolding can be associated with health issues.

Broader relevance: Proteins are ubiquitous in all living organisms and underpin metabolism, growth, and reproduction, making them central to biology, medicine, and nutrition.