Question: One common strategy for generating a rapid response is to use a positive feedback loop. The rapid…

One common strategy for generating a rapid response is to use a
positive feedback loop. The rapid release of cyt C from
mitochondria in response to cell damage could result from such a
positive feedback loop. For example, the caspases activated by cyt
C could act on mitochondria to release additional cyt c. To test
this possibility, cells expressing a cyt-c-GFP fusion were
incubated in presence or absence of broad spectrum caspase
inhibitor zVAD prior to exposure to a variety of apoptosis inducing
agents. The average time for release of cyt-c-GFP from mitochondria
in individual cells were then compared, as shown in figure
below.

Do your expectations match the observed results? Is a caspase
mediated positive feedback loop involved in cyt C release?