Brown Adipose Tissue

In this video I have explained briefly about three types of adipose tissues: white adipose tissue, brown adipose tissue and biege adipose tissue. The brown adipose tissue is abundantly seen in neonates and the quantity of it decreases as neonate develops into infant, child, adolescent and adult.
Brown adipose tissue has more mitochondria with high expression of an uncoupler protein called thermogenin. Thermogenin is also referred as uncouplin protein 1 (UCP1). Thermogenin acts as uncoupler of electron transport chain and uncouple oxidation from phosphorylation in electron transport chain. This way thermogenin in brown adipose tissue decreases the efficiency of electron transport chain thereby decreasing effective ATP generation from substrate oxidation.

Why Electrons flow from NADH to O2 in Electron Transport Chain

In this video I have explained the fundamental basis of electron transport chain that is the redox potential of NADH which is a electron donor and O2 which is a final electron acceptor. Electron transport chain which also referred as oxidative phosphorylation or respiratory chain runs with the redox potential difference of 1140 mv between NADH and O2. This drives flow of electrons from NADH to O2 via complex I, CoQ, III, cytochrome C and complex IV. The energy in the flow of electrons helps in pumping of protons across the membrane.