Question

There is a special type of tissue that is found in newborn babies, hibernating animals, and some animals that live in the Arctic. The cells of this tissue have normal mitochondria, but the mitochondria also include a special protein that is a H⁺ channel. This protein allows H⁺ ions to flow across the inner membrane of the mitochondria (thus making the membrane permeable to H⁺ ions).  

1. How do you think the presence of this additional protein affects cellular respiration (especially oxidiative phosphorylation) in these cells?

2. Why do you think this tissue is abundant in newborn babies and arctic animals, but not adult humans or animals in other climates?

Answer 1

1) during respiration, inner mitochondrial electron transporter transport electron form consequtively higher reduction potential and meanwhile protons are transported from mitochondrial matrix to the mitochondrial space and in this process, mitochondrial inter membrane will be more acidic and positive .

When these protons crosses inner membrane and enter matrix through ATO SYNTHASE HUGE AMOUNT OF ATP ID GENERATED BECAUSE PROTONS IS TRANSPORTED DOWN CONCENTRATION GRADIENT AND VOLTAGE GRADIENTS ALSO GIVES FREE ENERGY.

NOW IF SOME PROTEINS WHICH CROSSES PROTONS ACROSS INNER MEMBRANE, WILL REDUCE THE VOLTAGE GRADIENT AND CONCENTRATION GRADIENT OF PROTONS AND THUS , WHEN, H+ WILL BE TRANSPORTED THROUGH ATP SYNTHASE LEES ENERGY WILL BE PRODUCED .

AS, THIS FREE ENERGY WILL NOT BE CONVERTED INTO HIGH ENERGY BONDS FORMATION LIKE BONDS OF ATP..

As, these protons gradient is lost heat is generated as free energy is dissipitate as heat.

2)In newborn babies and arctic animal , they need body heat to maintain body temperature because environment is very cold ,so these channels is present in MITOCHONDRIA to produce heat as H+ gradient will be lost by the transport of H+ through that channels.

This helps the organism to maintain their body temperature.