prokarüootides

Prokarüootides are unicellular organisms that lack a membrane-bound nucleus and other membrane-bound organelles. They comprise two domains, Bacteria and Archaea, and are among the most diverse and widespread life forms on Earth, occupying habitats from soil and water to extreme environments and the bodies of other organisms.

Cell organization: Prokaryotic cells are generally small and simpler than eukaryotic cells. They typically have a plasma membrane and a rigid cell wall. Bacterial cell walls commonly contain peptidoglycan; archaeal walls do not and may consist of pseudopeptidoglycan or other polymers. Many prokaryotes possess exterior structures such as pili and flagella for adhesion and motility. Their genetic material is usually a single circular chromosome located in a nucleoid region, and many species carry plasmids. Ribosomes in prokaryotes are 70S in size.

Metabolism and growth: Prokarüootides display a wide range of metabolic capabilities, including photosynthesis (cyanobacteria), aerobic and anaerobic respiration, fermentation, and chemolithoautotrophy. They reproduce mainly by binary fission, but genetic exchange via transformation, transduction, and conjugation enables horizontal gene transfer and rapid adaptation.

Ecology and significance: Prokarüootides drive nutrient cycles (carbon, nitrogen, sulfur), decompose organic matter, and form symbiotic relationships that support ecosystems. They are fundamental to biotechnology and industry, contributing to fermentation, bioprocessing, and genetic engineering. The human microbiome includes many prokaryotes that aid digestion and immunity. Pathogenic bacteria cause disease in humans, animals, and plants; archaea are not known to cause human disease.