Question

Describe the structure and functions of mitochondria. Write two differences in function of mitochondria and chloroplasts.

Answer 1

Structure of mitochondria:

• The mitochondria are tiny bodies of varying shapes and sizes, present in the cytoplasm.
• Each mitochondrion is bounded by a double membrane envelope where the outer membrane is porous in nature whereas the inner membrane shows internal folds for increasing the surface area as compared to the surface area of the outer membrane.
• These inner membrane folds are called cristae which are embedded with small rounded bodies called oxysomes.
• The gel-like matrix fills the few small-sized ribosomes, a circular DNA molecule and phosphate granules.

Function of mitochondria:

• Mitochondria are sites of cellular respiration.
• They use molecular oxygen from the air to oxidise the carbohydrates and fats (lipids) present in the cell to carbon dioxide and water along with the release of energy.
• The organelle is responsible for synthesising adenosine triphosphate (ATP) which is used as the energy currency in the cell. Hence, the mitochondria is known as the 'powerhouse' of the cell.

Basis of contrast	Mitochondria	Chloroplasts
Function	They perform oxidation of food by releasing energy.	They synthesize food by photosynthesis.
	They consume Oxygen and liberate Carbon dioxide.	They consume Carbon dioxide and liberate Oxygen.