frumuvegg

Frumuvegg, or cell wall, is a rigid layer located outside the plasma membrane in many organisms, including plants, fungi, bacteria, and some algae and archaea. Animals and most protists lack a rigid cell wall, relying instead on the cytoskeleton and extracellular matrix for support and shape. The frumuvegg provides structural support, protects against osmotic lysis, and influences growth, development, and interactions with the environment.

Composition varies by lineage. Plant and many algal cell walls are dominated by cellulose, organized into microfibrils within a matrix of hemicelluloses and pectins; secondary walls may be reinforced with lignin. Fungi largely use chitin with glucans and glycoproteins. Bacteria commonly rely on peptidoglycan (murein), with Gram-positive and Gram-negative differences in cell wall architecture. Archaea may employ pseudopeptidoglycan or other polymers, while some algae incorporate silica or other materials in specialized cases.

Cell wall structure includes distinctions such as primary and secondary walls in plants. The primary wall forms during growth and is flexible, while secondary walls are deposited inside the primary wall for added rigidity. The middle lamella, rich in pectins, helps adhere neighboring cells. Synthesis and remodeling processes differ: plants use cellulose synthase complexes at the plasma membrane and wall-modifying enzymes; bacteria synthesize and cross-link peptidoglycan; fungi build chitin networks through chitin synthases.

Relevance extends to medicine, agriculture, and industry. Antibiotics like beta-lactams target bacterial cell wall synthesis. Plant cell walls influence fruit texture and digestibility, while cell wall properties are important in biofuel production and material science.