Cell - the smallest structures of all plant and animal life - the most mysterious phenomenon of nature.Even on its own level, the cell is extremely difficult to find and contains many structures that perform specific functions.In the body, a set of specific cells form tissues, tissues - organs, and those - the organ systems.The structure of animal and plant cells in many respects similar, but at the same time and have fundamental differences.For example, like the chemical composition of cells, similar principles of the structure and activity, but in plant cells have centrioles (except algae), and as nutritional substitutes base is starch.
animal cell structure based on three main components - the nucleus, cytoplasm and cell membrane.At the core of the cytoplasm forming protoplasm.Cell wall - a biological membrane (septum) that separates the cell from the external environment, wraps cell organelles and the nucleus, forming cytoplasmic compartments.If you put the preparation under the microscope, the structure of the animal cell can be easily seen.Cell membrane comprises three layers.The external and internal layers of protein and the intermediate - lipid.Wherein the lipid layer further divided into two layers - a layer of hydrophobic molecules and a layer of hydrophilic molecules, which are arranged in a certain order.On the surface of the cell membrane is a special structure - glycocalyx, which provides selectivity of the membrane.The shell passes the necessary material and delay those that are harmful.Animal cell structure aimed at providing a protective function even at this level.The penetration of substances through the membrane takes place with direct participation of the cytoplasmic membrane.The surface of the membrane rather significant due to bends, protrusions, folds and villi.The cytoplasmic membrane passes as the smallest particles and larger.
The structure is characterized by the presence of an animal cell cytoplasm, mostly consisting of water.Cytoplasm - a receptacle for organelles and inclusions.In addition, the cytoplasm contains the cytoskeleton - the protein filaments that are involved in the process of cell division, intracellular delimit and maintain cell shape, the ability to shrink.An important component of the cytoplasm - hyaloplasm which determines the viscosity and elasticity of the cell structure.Depending on the external and internal factors hyaloplasm can change its viscosity - becomes a liquid or gel.
Studying the structure of an animal cell, it is necessary to pay attention to the unit cell - organelles that are found in the cell.All organelles have their own specific structure, which is due to the functions performed.Core - central cell unit, which contains the genetic information and participates in the metabolism within the cell.For cell organelles include the endoplasmic reticulum, the cell center, mitochondria, ribosomes, Golgi complex, plastids, lysosomes, vacuoles.These organelles have in any cell, but, depending on the function, the structure of the animal cell may differ by the presence of specific structures.
functions of cellular organelles:
- mitochondria oxidize organic compounds and accumulate chemical energy;
- endoplasmic reticulum due to the presence of special enzymes synthesize fats and carbohydrates, it feeds contribute to transport substances inside the cell;
- ribosome synthesize protein;
- Golgi complex protein concentrates, condenses synthetic fats, polysaccharides, forms the lysosome and is preparing material to eliminate them from the cell or immediate use within it;
- lysosomes break down carbohydrates, proteins, nucleic acids and fats, in fact, enter the cell to digest nutrients;
- cell center is involved in the process of cell division;
- vacuoles, due to the content of the cell sap support cell turgor (internal pressure).
structure of living cells is extremely difficult - at the cellular level takes a lot of biochemical processes that provide the vital activity of the organism sovvokupnosti.
