2. Refer to the given figure and select the incorrect statement regarding X, Y and Z.
(A) Xis freely permeable to small molecules and ions.
(B) Yis arranged in characteristic pattern in different cells and bear oxysomes.
(C) Z contains respiratory enzymes, lipids, RNA, etc.
(D) None of these
Answers
Answer:
The correct answer is A.
'X is freely permeable to small molecules and ions' is an incorrect statement.
Explanation:
The given figure depicts Mitochondria, a double-membraned organelle, responsible for the production of ATP (energy currency).
X, Y, and Z are outer membranes, inner membrane and matrix of mitochondria respectively.
The inner membrane (Y)has many infoldings called cristae, and bear oxysomes. Oxysomes aid in the generation of ATP through proton motive force. The inner membrane also has ETC (electron transport chain) enzymes and carriers.
The matrix (Z) is the region having various respiratory enzymes, molecules like NADH, and genetic material (usually DNA).
The outer membrane (X) is SELECTIVELY permeable to ions and molecules. Since mitochondria take part in respiratory machinery, it becomes important to restrict the unregulated movement of ions and other molecules across the membrane, which hinders the biochemistry of mitochondria.
Therefore, the outer membrane is not freely permeable.