#GS-03 Science and Technology

For Prelims


  • Mitochondria is a membrane-bound organelle, present in the cytoplasm of the cell of Eukaryotic organisms.
  • It is called the powerhouse of the cell since it synthesizes energy molecules in the form of ATP (Adenosine Triphosphate).
  • Mitochondria plays a major role in cellular respiration.
  • It needs to take in oxygen and glucose to generate ATP.
  • Red Blood Cells or RBCs do not contain mitochondria.

Mitochondrial Structure:

  • Mitochondria in animals are in the shape of round or oval and are bound by a double membrane.

The different parts of mitochondria in animal cells are:

Outer Membrane
  • The outer membrane keeps the inner organelles in place and intact.
  • It is made up of protein and phospholipid
  • This layer is semipermeable to macromolecules which means that ions, ATP, ADP, etc. can easily pass through this membrane.
Inter Membrane Space
  • This is the space between the outer membrane and inner
  • This space also consists of small molecules like ions and sugars, as these molecules can easily pass through the outer membrane.
Inner Membrane
  • The inner membrane of the mitochondria is made up of proteins which have different functions to carry out.
  • It also has enzymes necessary which acts as catalysts in the production of ATP.
  • The inner mitochondrial membrane is permeable to smaller molecules such as oxygen, carbon dioxide, and water.
  • The inner mitochondrial membrane is the primary site for the generation of ATP.
  • The inner membrane of mitochondria has several folds which are called cristae.
  • The cristae increase the surface area inside the mitochondrial membrane which increases the efficiency of ATP generation.
  • The surface of the cristae has exosomes attached to it, which promotes the osmosis of ions.
  • Matrix
  • The space in the inner membrane which is not part of cristae is called the Matrix.
  • It contains proteins, ribosomes, enzymes, tRNA, and genomic DNA and is highly fluid.
  • The Mitochondrial Matrix can synthesize its RNA and proteins due to the presence of genetic material.

Functions of Mitochondria

The major role played by mitochondria is carrying out cellular metabolism.

Through cellular metabolism, it carries out three major processes.

  1. Conversion of food into energy
  2. Conversion of food into molecules that are essential for the body like proteins, carbohydrates, etc.
  3. Eliminations of the wastes.

Mitochondria also has the responsibility to carryout cell growth and multiplication.

It is also responsible for homeostasis by generating body heat.