Quiz 10: Isolation, Subfractionation, and Enzymatic Analysis of Beef Heart Mitochondria


In this problem, we are asked why we use sucrose in the mitochondria isolation buffer. Mitochondria, despite their function, are reasonably delicate. They require an environment that is polar (much like the cytosol they are extracted from), but not ionic. Sucrose meets both requirements - it is polar, and as a sugar it is not ionic. This buffer will stabilize the mitochondria as they are extracted.

In this problem, we are asked to describe the mode of action and function of sodium deoxycholate. Sodium deoxycholate is used in the protein assay; it functions as a detergent, releasing proteins from the membrane.

In this problem, we are asked to explain the derivation of the following equation for the activity of malate dehydrogenase. Specific activity = img This equation relates the activity of malate dehydrogenase to cause a change in the configuration of NADH. The A 340 value will change with time as malate dehydrogenase converts the NADH to NAD+; the 6.2 is a coefficient for NADH conversion at 340 nm.

There is no answer for this question

There is no answer for this question