In this I provide you All Knowledge about Cytoplasm and Organelles from Sindh text book board and Federal
The living matter of a cell is called protoplasm. In eukaryotic cells it can be divided into two parts i.e, cytoplasm and nucleus .
1=Cytoplasm: Cytoplasm is the region between nuclear membrane and plasma membrane. This is also a common component of prokaryotic and eukaryotic cells. The major difference between the cytoplasm of these two kids of cells is the presence or absence of cytoskeleton and membrane bounded organelles . These structures are absent in prokeryotic cells.
Physico_ Chemical nature of Cytoplasm:
It is about 90% water and forms a solution that contains all the fundamental biochemicas of life . Some of these are ions and small molecules in true solution , such as salts, sugar, aminoacids,fatty acids, nucleotides, vitami and dissolved gases. Other are large molecules, such as proteins, which form the colloidal solutions. The inner portion of Cytoplasm i.e: towards the nucleus is less viscous and is called cytosol while the peripheral part of Cytoplasm i.e towards the plasma membrane is more viscous and is called cytogel. A circular streaming movement can also be observed in cytoplasm due to the contractile activity of microfilaments . This movement is called cyclosis. which is responsible for distribution of cell contents in cytoplasm.
Metabolic and Storage role of Cytoplasm:
The cytoplasm acts as a site of metabolism and storehouse of a cell. The metabolic pathways generally occur in the cytosol which includes protein synthesis, glycolysis etc.
The cytosol is usually concerned with storage of usefull compounds which are subsequently used in various cellular activities and waste compounds which are eliminated from the cell time to time.
Cell organelles: In a eukaryotic cell, the cytoplasm contains highly organized discrete structures which are specific for various cellular functions are called cell organelles . The cell organelles are generally enclosed by the membrane except few such as ribosome.
Endoplasmic reticulum: An interconnecting network of cisternae elongated closed sacs which is generally extended from nuclear membrane throughout the cytoplasm of eukaryotic cells is called endoplasmic reticulum Er .
There are two types of Er , rough Er and smooth Er.
Rough Er: has ribosome attached to the sides facing the cytoplasm and has rough appearance under electron microscope.
Smooth Er: is continuous with the RER. Since ribosomes are not attached to it , therefore, it has smooth apperance eg. Metabolism of carbohydrates. The deoxidation of drugs and poison especially in the liver cells and synthesis of lipids including oil, phospholipids and steroid take place in smooth ER.
Ribosome: Ribosome were first observed using Electron microscope as dense granules. Ribsomes are roughly spherical, granular non membranous bodies found in both eukaryotic as well as prokaryotic cells However eukaryotic ribsomes are lager and characterized as 80S ribsomes while the prokaryotic Ribosomes are slightly smaller and are characterized as 70S Ribosomes.
Golgi complex: It is found in all eukaryotic cells. It was discovered by Italian biologist Camilo Golgi in 1898
Golgi complex consists of a stack of flattened memberane bound sacs called cisternae together with system of association vesicles called Golgi Vesicles it is a complex system of interconnected tubles formed around the central stack
Lysosomes: lyco mean splitting and soma mean body. These are single membranous, spherical vesicles. They contain digestive or hydrolytic enzymes. The lysosomal enzymes are made by the RER and then are transported to Golgi complex through SER.