Question

The highest number of Mitochondria are found in
A) Nervous
B) Skin
C) Connective
D) Muscle
E) Bone

Answer 1

Mitochondria is a membrane bound organelle and found in eukaryotic organisms. It is termed as the powerhouse of the cell because it generates most of the cell's supply of ATP as a chemical energy source.

Complete answer:
The number of mitochondria in a cell varies widely by organism, tissues.
RBCs have no mitochondria while liver cells can have more than 2000.
This organelle is composed of compartments that carry specific functions.
Mitochondrial proteins vary depending on the tissue and species.
Structure:

The outer mitochondrial membrane: It consists of large numbers of integral membrane proteins called porins.
The intermembrane space: It is the space between the outer membrane and inner membrane and this is also called peri mitochondrial space.
The inner mitochondrial membrane: It consists of more than 151 polypeptides.
The cristae space: Crista is a fold in the inner membrane.
The matrix: It is the space enclosed by the inner membrane and it is important in ATP production.
Functions:
Energy conservation- helps in ATP production which occurs by oxidizing glucose: pyruvate and NADH.
Citric acid cycle- Pyruvate transported across the inner mitochondrial membrane into the matrix where the oxidized or combined with coenzyme A to give acetyl-CoA, $CO_2$ and NADH.
Heat production and storage of calcium ions.
Regulation of membrane potential and cellular metabolism.
The cells with extensive metabolic activities have a great number of mitochondria. The highest number of mitochondria are present in muscles because the energy requirement of muscle is high.

Hence the correct answer is option ‘D’ Muscle.

Note: In the heart muscle cells about 40% of the cytoplasmic space is taken up by the mitochondria. In liver cells 20-25% of cytoplasmic space taken by 1000-2000 mitochondria per cell.