Breath and a metabolism. Supply by energy and building blocks. Storage and energy use

you are: Breath and a metabolism. Supply by energy and building blocks

We Will discuss first of all processes of storage, liberation and energy use. Chemical energy of organic connections - the transformed form of a solar energy - is concluded in structure of chemical bonds of these connections. At rupture of communications, usually in the course of oxidation, energy is liberated. When any organic material, for example wood, burns down (is oxidised), all energy containing in it is liberated entirely, mainly in the form of heat. in a plant such simultaneous liberation of a considerable quantity of energy would be, obviously, useless as it could not be used in the ordered, multistage constructive processes. Live organisms manage to use energy of chemical bonds thanks to that oxidation consists at them of a number of stages so energy is liberated by small portions which can be spent there and then in any other processes. The liberated energy goes on formation of new chemical bonds rich with energy, is frequent in the form of ATR (' power currency> cages; fig. 5.1) about what we already spoke earlier.

One of the main forms of such gradual oxidation is made by carrying over process elektronov, proceeding in mitohondrijah. At this process elektrony move on a carrying over chain elektronov, i.e. Pass from one carrier to another, each time to a little lower power level.

Moving in a similar way ' downwards ' from partially restored connection (carbohydrates) to that point where they eventually incorporate to oxygen, elektrony at each stage give any part of the energy, the certain which share is caught in the form of ATR. At photosynthesis two chains of carrying over elektronov operate: one - for cyclic fotofosforilirovanija, carried out by photosystem I, and another - for not cyclic fotofosforilirovanija, connecting photosystems II and I. Both these systems deliver ATR, and photosystem II - also regenerative force (NADPH) for fixing СО2 and for its restoration to level of carbohydrates. In other cellular reactions it is used ATR, formed mainly in the course of oxidising fosforilirovanija. Oxidizing fosforilirovanie it is connected with process of breath and it is carried out by means of other chain of carrying over elektronov which we also will shortly consider.

Gradually, i.e. In some stages, it should be made not only disintegration of organic molecules (for this necessary condition of effective storage and energy use), but also synthesis of difficult connections - fibers, nucleinic acids, lipidov or polisaharidov. When larger are under construction of simple molecules, activation quite often is required to these simple molecules; differently, energy enough should be informed them that reaction could come to the end. Thereof synthesis of this or that connection often proceeds more difficult way, rather than its disintegration.