Question

A patient with Luft discase presented with general weakness, excessive perspiration, a high caloric intake without increase in body weight, and an excessively elevated basal metabolic rate. Luft disease was the first disease involving a defect in mitochondria to be described. It is a defect in the mechanism that controls oxygen utilization in mitochondria. Which of the following is a characteristic of mitochondria? A. The inner membrane forms cristac and contains small spheres attached by stalks on the inner surface. B. Only the outer membrane has transmembrane systems for translocation of metabolites. C. The mitosol is relatively inert metabolically. D. Mitochondrial DNA is similar to nuclear DNA in size and shape. E. Mitochondria have no role in apoptosis.

Short answer

A: The inner membrane forms cristae and contains small spheres attached by stalks on the inner surface. B: Both the inner and outer membranes have transmembrane systems for translocation of metabolites. C: The mitosol is relatively inert metabolically. D: Mitochondrial DNA is larger in size compared to nuclear DNA. E: Mitochondria do not play any role in apoptosis. Answer: A: The inner membrane forms cristae and contains small spheres attached by stalks on the inner surface.

Step-by-step solution

Eliminate Incorrect Statements

To find the correct statement about mitochondria, we must first eliminate the statements that are inaccurate or false. B: Incorrect- Both the inner and outer membranes of mitochondria have transmembrane systems for translocation of metabolites. C: Incorrect - The mitosol or the matrix of mitochondria contains many metabolic enzymes, as well as small circular DNA molecules, which means it is not relatively inert metabolically. D: Incorrect - Mitochondrial DNA (mtDNA) is much smaller in size and circular in shape, while nuclear DNA is much larger and linear in shape. E: Incorrect - Mitochondria play a significant role in apoptosis, or programmed cell death.

Identify the Correct Statement

After eliminating the incorrect statements, we are left with one option: A: The inner membrane forms cristae and contains small spheres attached by stalks on the inner surface. This statement is correct, as it accurately describes the structure of the inner membrane of mitochondria. The cristae (folds) in the inner membrane provide a large surface area for metabolic processes, and the small spheres attached by stalks are the ATP synthase complexes involved in energy production. So, the correct answer is A.