Functions of Organelles

The cell, especially eukaryotic, is a complex open system. Performing various functions the parts of this system ensure its integrity. Functions of the organelles is interrelated and is aimed at maintaining the integrity of the cell, resisting the destructive effects of the environment, the development of the cell, its division.

Below listed the functions of the basic cell organelles of eukaryotes. The prokaryotes havn't the nucleus and membrane organelles. Organelle functions perform invaginations of the cytoplasmic membrane on which the enzymes are located.

Functions of the cell nucleus:

• Management of biochemical processes in the cell by regulation of gene expression
• Copying genetic information (DNA) before dividing
• Synthesis of RNA, assembly of ribosomal subunits

Meaning of the cytosol (but it is not an organelle):

• The environment for many biochemical reactions
• Movement of the cytosol provides displacement of organoids and substances
• It unites the parts of the cell into a single whole

The cytoplasmic membrane:

• Barrier function: It separates the inner components of the cell from the external environment
• Transport function; including selective transport of substances
• Enzymatic function; many immersed in the membrane protein molecules and complexes are enzymes
• Receptor function
• Phagocytosis and pinocytosis (some cells)

The cell wall (plants):

• Carcass function
• It prevents stretching and rupturing the cell,
• defines the shape of cells
• Transport function: the cell wall forms the vessels of xylem, tracheid and sieve tube elements
• Walls of all cells provide a support for a plant, create something like a skeleton
• Sometimes this is a place for storing nutrients

Ribosomes:

• Protein synthesis. They provide a connection between the molecules of mRNA, tRNA and enzymes, which occupy their "places" in the ribosome.

Mitochondria:

• Energy station of the cell: synthesis of ATP molecules due oxidation-reduction reactions; oxygen is consumed and carbon dioxide is released.

Chloroplasts:

• Photosynthesis - synthesis of organic substances from inorganic by using light energy. Herewith, carbon dioxide is absorbed and oxygen is released.

The endoplasmic reticulum:

• The membranes of the ER are the place of attachment of many ribosomes synthesizing polypeptides; after synthesis, the protein turns out in the ER's channels, where it "ripens".
• In the ER's channels, lipids and carbohydrates are synthesized
• Transport of substances in the Golgi apparatus

The Golgi apparatus:

• "Maturation" (modification) of substances synthesized in the cell
• Secretion from the cell through exocytosis
• Construction of the cell membrane
• Formation of lysosomes

Lysosomes:

• Splitting of nutrients that enter the cell (intracellular digestion)
• Destruction of unnecessary organelles
• Cell autolysis (self-destruction)

Peroxisomes:

• Decomposition of hydrogen peroxide into oxygen and water. Peroxide is toxic for cells

The centrosome:

• Forms the spindle apparatus during mitosis and meiosis
• Creates microtubules, basal bodies of flagella and cilia