Final answer:
The major isoenzyme fraction in the sera of healthy individuals is LD-2, followed by LD-1, LD-3, LD-4, and LD-5. LDH exists in multiple isoenzyme forms, with different physical characteristics and functions in different tissues. Analysis of LDH isoenzyme levels in blood serum can help diagnose tissue damage.
Step-by-step explanation:
The question pertains to the major isoenzyme fraction in the sera of healthy individuals. Lactate dehydrogenase (LDH) is an enzyme that exists in multiple isoenzyme forms, which have different physical characteristics such as molecular weight and charge. In the case of healthy individuals, the major isoenzyme fraction of LDH in the sera is LD-2, followed by LD-1, LD-3, LD-4, and LD-5.
These isoenzymes have different affinities for pyruvate, resulting in variations in the conversion rate of pyruvate to lactate. LDH-1, or H₁, is predominantly present in the cardiac muscle, while LDH-5, or M4, is more abundant in the skeletal muscle. Analysis of LDH isoenzyme levels in blood serum can be used to diagnose tissue damage in organs such as the liver and heart.
Overall, the question is about the major isoenzyme fraction of LDH in the sera of healthy individuals, and the different isoenzyme forms and their functions in various tissues.