All living organisms, depending on the availability of the kernel can be divided into two broad categories: prokaryotes and eukaryotes.Both terms are derived from the Greek «karion» - kernel.
Those organisms which have no nucleus, called prokaryotes - pre-nuclear organisms nuclear material in the form of inclusions.The structure of the eukaryotic cell is somewhat different.In contrast to prokaryotes, eukaryotes have a formalized core - this is the main difference between them.For prokaryotes include bacteria, cyanobacteria, rickettsia, and other organisms.For eukaryotes include representatives of the kingdoms of fungi, plants and animals.
structure of eukaryotic cells of different organisms Nuclear similar.Their main components - the nucleus and cytoplasm, which together constitute a protoplast.The cytoplasm is a semi-liquid basic substance, or, as it is called, hyaloplasm, which are cellular structures - organelles that perform different functions.From the outside the cytoplasm is surrounded by a plasma membrane.Plant and fungal cells have a plasma membrane besides cell membrane tougher.The cytoplasm of plant cells and fungi contains vacuoles - bubbles which are filled with water and various dissolved substances.In addition, in the cell are included in a reserve nutrients or end products of metabolism.Features of the structure of the eukaryotic cell functions due to inclusions that are in the cell.
Structure and function of eukaryotic cells :
- plasma membrane - a lipid bilayer with proteins embedded in it.The main function of plasma membrane - the exchange of substances between the cell and the environment.Due to the plasma membrane is carried out and the contact between two adjacent cells.
- core - this element has dvumembrannuyu cell membrane.The main function of the nucleus - the preservation of genetic information - deoxyribonucleic acid.Due to kernel regulate cell activity, genetic material passed to daughter cells.
- mitochondria - these organelles are present only in plant and animal cells.The mitochondria, as well as the core are two membranes between which there are internal folds - Kristen.In the mitochondria contains circular DNA, ribosomes, the set of enzymes.Thanks to these organelles carried oxygen breathing phase cells (synthesized adenosine triphosphate).
- plastids - are available only in a plant cell, as their main function - photosynthesis.
- endoplasmic reticulum (reticulum) - is a system of flattened sacs - tanks, cavities and tubes.In the endoplasmic reticulum (rough) arranged important organelles - the ribosome.The tanks are insulated networks and ripen proteins that are transported as the network itself.On smooth reticulum membranes of the synthesis of steroids and lipids.
- Golgi apparatus - a system of flat odnomembrannyh tanks and bubbles attached to the ends of tanks advanced.The function of the Golgi complex - the accumulation and transformation of proteins and lipids.Here are formed secretory vesicles that present material outside the cell.The structure of the eukaryotic cell such that the cell has its own mechanism for the allocation of waste substances.
- lysosomes - odnomembrannye vesicles that contain hydrolytic enzymes.Due to the lysosomes digest damaged cell organelles, cells dead bodies.
- ribosome - are of two types, but their main function - to build protein molecules.
- centrioles - a system of microtubules, which are constructed from protein molecules.Thanks centrioles formed internal skeleton of the cell, it can maintain its permanent shape.
structure of the eukaryotic cell is more complex than prokaryotic cells.Thanks to the kernel, eukaryotes have the ability to transfer genetic information, thereby ensuring consistency of its kind.
