This statement is incorrect about mitochondrial membrane

The correct option is: "outer membrane embeds enzymes of electron transfer chain"

To understand why this statement is incorrect (and thus the correct answer to the question), let us analyze the structure and function of the mitochondrial membranes step-by-step:

1. Structure of the Outer Mitochondrial Membrane:
The outer mitochondrial membrane contains large pore-forming proteins called porins (specifically, VDAC or Voltage-Dependent Anion Channels). Because of these porins, the outer membrane resembles a sieve and is highly permeable to small molecules, ions, and nutrient molecules (like pyruvic acid) up to about 5000 Daltons. Therefore, the options stating that the outer membrane resembles a sieve and is permeable to molecules are correct statements regarding its physiology.

2. Localization of the Electron Transport Chain (ETC):
The enzymes and protein complexes involved in the electron transfer chain (ETC)—namely Complex I, II, III, IV, and ATP synthase—are embedded in the inner mitochondrial membrane, not the outer membrane. The inner membrane is highly folded into structures called cristae to increase the surface area available for these energy-generating chemical reactions and is selectively impermeable to maintain the proton gradient necessary for ATP synthesis.

Therefore, the statement "outer membrane embeds enzymes of electron transfer chain" is biologically incorrect, making it the correct option for this question.