THE ROLE OF MITOCHONDRIA IN AGING

Aging is a process drawing attention of many researcher, and at presen t many theories exists, which try to explain this chain of inevitable events leading to death of organism. In this article we focused our at tention on a theory explaining the degenerative changes occurring duri ng aging by the effect of oxygen free radicals. These highly reactive radicals are produced during oxidative phosphorylation in mitochondria . All cellular components appear to be sensitive to oxygen-radical dam age. Lipids, proteins and nucleic acids are probably the most suscepti ble to this injury. Lipoperoxidation of lipids together with cross-lin king of proteins with phospholipids and nucleic acids caused changes i n membrane fluidity. Mitochondrial DNA coding several subunits of resp iratory chain enzymes can be also damaged by these radicals. All these changes together have negative impact on mitochondrial metabolism res ulting progressive decrease of the efficiency of oxidative phosphoryla tion and thus of the whole organism.