can anyone answer either of these questions?? Hibernating animals and newborn in
ID: 266603 • Letter: C
Question
can anyone answer either of these questions??
Hibernating animals and newborn infants have a high proportion of brown fat. Brown fat contains a protein called thermogenin, which acts as an uncoupler (i.e. electron transport is uncoupled from oxidative phosphorylation). As discussed in class, thermogenin allows protons (H') back into the mitochondrial matrix bypassing ATP synthase e. i. Does the rate of ATP synthesis increase, decrease, or stays the same in the presence of an uncoupler? Explain your answer. i. For hibernating animals and newborn infants, explain what the physiological advantage is of having electron transport uncoupled from ATP synthesis (i.e. what happens to the energy generated from electron transport)?Explanation / Answer
1) In the presence of an uncoupler such as thermogenin, ATP production decrease. In oxidative phosphorylation, ETC is coupled with ATP synthesis. The protons pumped by the electron transport chain in the intermembrane space of mitochondria create a potential gradient, which drives the production of ADP through ATP synthase in order to synthesize ATP. ATP synthase is an enzyme that couples the movement of protons back to the inner membrane of mitochondria. This provides enough free energy for production of ATP from ADP. In the presence of uncouplers such as thermogenin, the protons pumped to the intermembrane escape back to the inner membrane of mitochondria without passing through the ATP synthase. They do this by increasing the permeability of the inner mitochondrial membrane, allowing protons that have been pumped into the intermembrane space to return to the mitochondrial matrix. Thus, ATP is not generated, hence in presence of uncouplers ATP production decreases.
2) The uncouplers confer a physiological advantage to hibernating animals and newborns. The uncouplers such as thermogenin bypass proton transport through ATP synthase which leads to generation of heat instead of ATP production. This helps the animals to cope with the increasing cold and helps in thermoregulation of the body tempertaure.
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