Question

1. Why would the homogenate fraction have the highest succinate dehydrogenase activity and thus the most mitochondria ( more than the S1,P1,S2 and P2 fraction).

SDH activity Initial Velocity (Abs./s) P1 Fractions Figure 2. The SDH of each fraction measured in velocity (Abs./sec). The H fraction had the highest initial velocity of 0.057 Abs./s while the P2 fraction had the lowest initial velocity of 0.0033 Abs./s.

Answer 1

Answer:

S fraction is soluble fraction.

Its prepared by disruptive biochemical methods. That is soluble in water. Also this can be supernatant fraction in centrifugation.

P fraction is pellet fraction.

Its prepared by centrifugation.

Homogenate is obtained by centrifugation and chemical treatment. The difference is its suspended in solution.

More denser and larger particles settle down and become pellet fraction. This mainly includes nucleus.

Less denser particles like mitochondria will be in homogenate. So more concentration of mitochondria in homogenate than other 2 fractions.

Light weight or smaller partices will be in supernatant if centrifuged in a low speed.

This is why homogenate has got maximum mitochondria and maximum succinate dehydrogenase activity.