According to the cellular theory, each cage is capable to independent activity: it can grow, breed, exchange substance and energy with the environment. The internal organization of cages in many respects depends on the functions which are carried out by them in a metaphyte, however all of them have a unified plan of the building.
Instruction
1. Similarities in structure of the cells – the cytoplasmatic cage of a membranasnaruzha is covered with a cytoplasmatic membrane 8-12 nanometers thick. This cover is constructed of a bilipidny layer. Each molecule of a lipid has a hydrophilic head which sticks out outside, and the hydrophobic tail turned inside. Such double layer of fat cages provides barrier function of a membrane thanks to which contents of a cage do not spread and in it dangerous substances do not get.
2. What role is played by the molecules of proteins shipped in a bilipidny layer membranyv a bilipidny layer of a cellular cover numerous proteinaceous molecules are shipped. Some of them lie on a surface (from external or inside), others penetrate a membrane through. These membrane proteins perform a number of the major functions – receptor, transport, enzymatic. By means of some of them the cage perceives irritations, on others transport of various ions is carried out, the third catalyze cell activity processes.
3. What is represented fagotsitoz and pinotsitoz and why they are necessary kletkekrupny food particles cannot get freely through a cell membrane. The cage absorbs them by a pinotsitoz or a fagotsitoz. In the first case firm particles, in the second – liquid with the substances dissolved in it are absorbed and involved. The general name for these processes – endotsitoz. There is also the return to it process – ekzotsitoz during which the substances synthesized by a cage (for example, hormones), are packed into membrane bubbles, approach a cell membrane, are built in it and throw out contents outside. The same way the cage gets rid of metabolism products.
4. Special functions of a membrane at cages-prokariotovu of prokaryotic cells, i.e. nuclear-free, the cellular membrane carries out also some other functions. The cover of bacteria has numerous internal "embolies" and folds – mesosom. On their surface there are enzymes providing reactions of a metabolism. Mesosom of prokaryotic cells perform functions of mitochondrions, plastids, endoplasmic network, Golgi's complex or lysosomes.