Question

Please answer this question in detail (with relevant diagrams and examples).

3. Please describe how (i.e. by what mechanism) the increased activity of uncoupling proteins can increase the amount of heat generated by a cell.

*for biochemistry

Answer 1

Respiratory process oxidises coenzymes and in this process protons are pumped outside the mitochondrial inner membrane. Pumping of protons outside the membrane create a proton gradient and this process slow down the process of respiration. The protons flow back to mitochondrial matrix through ATP synthase. ATP synthase utilizes this proton gradient and the energy of back flow of protons is conserved by producing ATP. This back flow of protons also activates respiration; the process is termed as respiration coupling.

Uncoupler are proteins present in mitochondrial membrane, which facilitate the re-entry of the protons to the matrix without entering through ATP synthase. As the proton moves back through these uncouplers, the energy of back flow of protein is not conserved in the formation of ATP and thus gets dissipated as heat.

Uncouplers are naturally present in few plants and animal cells. Thermogenin is such an uncoupler which is found in new born animals Brown Adipose Tissue (BAT). Mitochondria of BAT has thermogenin which allows backflow of protons thus producing heat which keeps new born baby warm.

Ht HT (H7 H+ HT HAH ADP v When it mores back through ATP synthase. ththt Htt 4tht Meat ht I produced When Ht moves back through an funcouples Cucp). The process produce