singlemembranebound

Singlemembranebound refers to cellular structures that are enclosed by a single lipid bilayer, as opposed to those surrounded by two membranes. In eukaryotic cells, many organelles and vesicles of the endomembrane system are single-membrane bound, reflecting their origin in membrane budding and fusion events within the cell. These compartments typically carry out specialized metabolic, degradative, storage, or trafficking roles.

Common examples include lysosomes, endosomes, peroxisomes, and vacuoles. Lysosomes are acidic, enzyme-filled organelles responsible for degrading macromolecules. Endosomes function as sorting hubs for endocytosed material, with early endosomes maturing into late endosomes that deliver cargo to lysosomes. Peroxisomes carry out fatty-acid beta-oxidation and other detoxification reactions. Vacuoles, especially the central vacuole in plant cells, store water and ions, sequester waste, and contribute to turgor pressure. Transport vesicles derived from the Golgi or plasma membrane are also single-membrane-bound carriers that move cargo between compartments and to the cell surface.

Formation and dynamics of single-membrane-bound structures involve vesicle budding, fusion, and, in some cases, growth and division of existing organelles. Proteins that govern vesicle formation and targeting ensure correct localization and function. Clinically, defects in single-membrane-bound organelles can lead to disease, such as lysosomal storage disorders from defective hydrolytic enzymes or peroxisomal biogenesis disorders affecting multiple metabolic pathways.

Singlemembranebound is thus a broad category describing many essential cellular compartments distinct from double-membrane-bound organelles like the nucleus, mitochondria, and chloroplasts.