Question

Which of the following statements regarding mitochondria is incorrect?
A) outer membrane is permeable to monomers of carbohydrates, fats and proteins
B) enzymes of electron transport are embedded in the outer membrane
C) inner membrane is convoluted with infolding
D) mitochondrial Matrix content singles circular DNA molecule and ribosomes

Answer 1

Hint: Mitochondria is a semi-autonomous membrane which is a bounded organelle found in the cytoplasm of many eukaryotic cells. The enzyme required for the production of ATP molecules is located in the inner mitochondrial membrane.

Complete answer:
The size of the mitochondria is in the range of 0.75 and 3 micrometres. The main function of mitochondria is to produce energy in the form of ATP. Other functions of mitochondria include signalling, cellular differentiation, cell death and also maintains the growth of cell cycle. Its number varies from cell to cell. For example, RBC lacks the mitochondria but liver cells contain more than 2000 per cell. This mitochondrion is composed of compartments which include the outer membrane, inner membrane, the intermembrane space, cisternae and the matrix. Mitochondria has its own genetic material. In mitochondria, the enzyme such as ATP synthase required for electron transport is present in the inner membrane and not in the outer membrane. The outer membrane is a relatively simple phospholipid bilayer, that contains protein structures called porins which help molecules of about 10 kilodaltons or less (the size of the smallest proteins) to enter. Ions, nutrient molecules, ATP, ADP, etc. can pass through the outer membrane with ease.
Thus, the correct answer is option B.

Note: Human mitochondria have their own genome and it is a circular DNA. The genetic material is about 10-kilogram bases, where it encoded almost 37 genes, and the code of respiratory complex, tRNA and one mitochondrion contains 2 to 10 copies of its DNA.