the Cage of a green plant. Mitohondrii

you are: the Cage of a green plant

In a typical cage there is a set mitohondry, disseminated on all cytoplasm respiratory organell, under the form slightly reminding a cucumber. Their length fluctuates usually from one to several micrometers, and the width makes about 0,5 microns though in especially active cages contain sometimes larger and more numerous mitohondrii. Everyone mitohondrija is surrounded by a double membrane; the internal membrane forms set lamellar vyrostov which are called kristami. This internal membrane divides, thus, mitohondriju into two compartments, or kompartmenta: space between internal and external membranes mitohondrii and internal matriks, limited to an internal membrane.

The External membrane mitohondrii it is easy pronitsaema for bolshej parts of small molecules and ions. Various oraanicheskie molecules, and among them piruvat - the three-carbon connection formed at disintegration of six-carbon sugars in cytoplasm, pass through this membrane and then are oxidised to С02 and Н20 in a series fermentativnyh reactions. at the oxidation of molecules proceeding inside mitohondrii, liberated energy is reserved in the form of special - phosphatic communications rich with energy - adenozintrifosfata (ATR) (gl. 4). The cage can use energy of these communications for performance of the most various work, and, hence, continuous oxidation in mitohondrijah supplies its necessary ' with power currency ' in the form of ATR.

Arriving in mitohondriju piruvat at first breaks up on С02 and ' the activated acetate ' - the two-carbon fragment involved in a cycle of oxidising reactions, carrying the name of a cycle of Krebsa Each of reactions of this cycle kataliziruetsja the special enzyme which is present in matrikse mitohondrii. At separate stages of a cycle elektrony and protons are transferred from intermediate products of a cycle on the respiratory enzymes containing such derivatives of vitamins, as NAD + (derivative nicotinic acid) and FAD (derivative riboflavina). These carriers pass such way to the restored form.

NADH and FADH2, and then transfer the elektrony and protons to other carriers which are a part of respiratory ensembles. Finally they are transferred to oxygen which as a result of it is restored to Н20. Carriers elektronov, located in a certain order, take places on internal membranes mitohondry. When elektrony protons are transferred from one carrier to another, liberated energy is used for synthesis ATR from ADP and inorganic phosphate (P1). Subsequently at disintegration ATR to ADP and P1 energy is liberated again and can be used in any other reactions or the processes going with consumption of energy.