Cell as a holistic system
A living eukaryotic cell is a uniquely organized system, the interaction of all its components ensures the vital activity of the cell as an integral unit. Its main components include plasmolemma, cytoplasm and the nucleus, however, many cells have additional organelles - specialized structures dissolved in the cytoplasm and participating in the metabolism and energy of the cell.
Thus, the functions of a ribosome are
protein synthesis, mitochondria produce
macroergic compounds, microtubules play the role of a cell skeleton and provide intracellular transport, and the endoplasmic reticulum and Golgi complex are the main "stations" in metabolism. In this case, all reactions occur in the cytoplasm, which is in constant motion.
Membrane organelles and their functions
Ribosomes perform their functions on the EPR, where they are transported through the pores of the nuclear membrane immediately after formation. EPR is a membrane organelle, consisting of many tubes and pockets, turning into each other and communicating with the lumens of the shell of the nucleus. In the cell, there are two parts of the endoplasmic reticulum, which differ in both structure and function: rough and smooth. The first of them carries ribosomes, the structure and functions of which are laid down even when leaving the nucleus, there are no ribosomes on the second, and it participates in the synthesis of lipids and steroids of the cell, stores intracellular calcium, dephosphorylates glucose-6-phosphate in the liver. But both types of EPR are inconsistent structures and are subject to frequent changes, as is the Golgi complex. It is similar in structure to the EPR and consists of a complex of cisterns, and its function is to modify the primary proteins synthesized on SER, the formation of lysosomes, the accumulation of secretory substances and their transport from the cell.
Non-Membrane Organoids
The cell also contains non-membrane organoids: the cytoskeleton, centrioles, inclusions of storage substances (lipids, polysaccharides, biologically active substances or pigments) and the ribosome. The functions of each of them are regulated by the inverse mechanism, that is, they depend on the nature of the current metabolism: inclusions appear in the cell only when they are synthesized excessively, centrioles double when the cell passes to division, and microtubules increase their activity in the phase of opening transport channels and chemotaxis in phagocytes . The functions of the ribosome in a human cell are relatively constant and differ little from those in a plant cell. They consist of ions, some biopolymers and condensed RNA, assembled into two subunits - 30S and 50S (by Svedberg sedimentation coefficient), thus making up 80S ribosomes. This is an extremely important factor that makes it possible to distinguish human ribosomes from ribosomes of bacteria having a 70S structure, since antibiotics are prescribed in the treatment of bacterial infections that can partially or fully block the functions of 70S ribosomes, thereby inhibiting protein synthesis in the bacterial cell and interfering with its vital functions.