style="text-align: left;"> The free radical theory of aging
Dr.Denham Herman a scientific researcher who proposed the 'free radical theory of aging' in the year 1956.according to this theory the process of aging is due to oxidative damage of cell organelles and other cytoplasmic contents by free radicals. intially it was assumed that the free radicals such as ROS(reactive oxygen species) produced during normal respiratory process.The free radical theory got more attention when researchers studied the cause of cancer ,Alzheimer disease,and heart diseases .This theory realises that old age is just another disease,our old age is starting when mitochondrial DNA (mtDNA) get damaged by free radicals.1970s many scientist involved in Reserch related to this theory and in 1980 J.Miquel clearly explained the mitochondrial involvement in the production of free radicals,the theory is known as mitochondrial theory of free radicals.
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| Cell structure |
Mitochondria(mitochondrion-singular)
Mitochondria are tiny cellular organelles which are freely distributed in cytoplasm,they are covered with two membranes.The outer membrane is a double phospholipid layer,it covers and protects the inner part of the organelle and the inner one folded many times and forms structures called cristae,the fluid filled inner space of the organelle is called matrix.mitochondria has its own DNA(mtDNA)and ribosomes. mitochondria are often called as power houses of cell,they produce energy and stored in it.The energy that released from metabolic activities are using to convert ADP(adenosine diphosphate)to ATP(adenosine triphospate),when energy utilised ATP will change to ADP.More mitochondria are present in such cells which need more energy,for example muscle cells contain more mitochondria because it needed more energy for muscular activities,the Neuron has the least numer of mitochondria because it's function is to conduct electric impulses to and fro from central nervous system and deferent parts of the body,it need not much energy to work,and RBC( red blood corpacells)has no mitochondria because it need no extra energy to perform it's function,it work as oxygen carriers,the haemoglobin present in the RBC capable of doing the work.Most of the metabolic process is done inside mitochondria with the help of oxygen,this process is also called cellular respiration.
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| internal view |
