Question

In mitochondria, protons accumulate in the
A. Outer membrane
B. Inner membrane
C. Intermembrane space
D. Matrix

Answer 1

Hint: Mitochondria are double membrane bound cell organelles which are present in cytoplasm of the cell. They are called powerhouse of the cell as they produce the chemical energy in the form of ATP. They have an outer membrane and inner membrane which is separated by intermembrane space.

Complete answer:
Mitochondria are double membranous structures which are present in the cell cytoplasm of almost all eukaryotes. They are responsible for ATP production through cellular respiration and hence are called powerhouse of the cell. The structure of mitochondria consists of the following:
> Outer membrane
> Intermembrane space
> Inner membrane
> Cristae
> Matrix
According to the question, protons in mitochondria accumulate in the intermembrane space. These protons are transported from the matrix to intermembrane space to produce the proton motive force or chemiosmosis. It is the process of movement of ions across the mitochondria, down their electrochemical gradient. This proton motive force depends on two factors: diffusion force caused by concentration gradient and electrostatic force caused by electrostatic potential gradient. These two gradients together form electrochemical gradients or electrical gradients. It is a measure of potential energy stored as a combination proton and voltage gradient.

Thus, the correct answer is option C.

Additional information:
Mitochondria has various functions, such as,
> It plays an important role in apoptosis, cell death.
> It regulates metabolic activity of the cell.
> It produces ATP through oxidative phosphorylation.
> It promotes cell multiplication and growth.
> Helps in detoxifying liver cells.

Note:
Mitochondria not only helps in carrying out various processes but is also a cause of various disorders. Mitochondrial disorders are hard to detect as its symptoms vary from person to person. In severe cases, it can lead to organ failure. A few mitochondrial disorders are, Alpers disease, Barth syndrome.