Question

Newborn babies have "brown fat" cells that make a mitochondrial inner membrane protein called UCP1, that acts as a channel for facilitated diffusion of protons. When this channel opens, what will be the effect on the proton gradient across the inner mitochondrial membrane?
a.the proton gradient will increase
b.the proton gradient will decrease
c.the proton gradient will stay the same

Answer 1

Answer:

the proton gradient will decrease

Explanation:

The proton concentration gradient is generated across the inner mitochondrial membrane. It is maintained since the inner mitochondrial membrane is impermeable for protons. Therefore, intermembrane space has a higher concentration of proton than the matrix. The opening of UCP1 that facilitates the diffusion of protons would dissipate the proton concentration gradient as protons will move back to the matrix through the opened channels. The proton concentration will be lost as heat.