1.Structural organization of cells

Structural Organization of the Cell – Overview of Cell Components The cell is the smallest structural and functional unit of an organism, capable of independent life. It arises from other cells through cell division (proliferation). The cell consists of a nucleus and cytoplasm, containing organelles that are bounded by the plasma membrane. These organelles can be categorized into membranous and non-membranous types. Membranous Organelles: 1. Rough Endoplasmic Reticulum (RER) and Smooth Endoplasmic Reticulum (SER): RER is involved in protein synthesis by polyribosomes, which produce proteins destined for secretion out of the cytosol. SER, on the other hand, participates in phospholipid and steroid hormone synthesis, detoxification of toxins, and calcium release (abundant in muscle cells, specifically the sarcoplasmic reticulum). 2. Golgi Apparatus: This organelle modifies and packages proteins synthesized in the RER. 3. Lysosomes: Lysosomes serve as the site of intracellular digestion. 4. Mitochondria: Mitochondria are responsible for aerobic respiration and ATP production. 5. Peroxisomes: These organelles contain enzymes involved in lipid metabolism. 6. Nucleus: The nucleus houses the cell’s genetic material. Non-membranous Organelles: 1. Free-Floating Ribosomes: These ribosomes synthesize proteins for use within the cell. 2. Centrosome: Composed of a pair of centrioles, the centrosome acts as the organizing center for microtubules. 3. Cytoskeleton: The cytoskeleton includes microtubules, actin filaments, and intermediate filaments, providing structural support and facilitating cellular movement.