Right !!- The food
vacuole undergoes fusion with lysosomes shortly after it is formed. This
explains the existence of the proton pumps 5 min after feeding but
NOT 30 sec after feeding (apparently, at this point the fusion process
has not yet occurred). As migration continues, parts of the lysosome- membrane
(containing the proton pumps) are recycled by the cell and are pinched
off the vacuole, thus allowing the pH to increase. This is evident by the
observed absence of the proton pumps 10 min after feeding.
We have previously noticed that the size of an early
(30- sec) food vacuole is smaller than the size of the later (5 min) food
vacuole and of the same size as the latest food vacuole (10 min). These
findings support the fusion theory (hypothesis C), but they do not prove
it beyond any doubt.
Continue to the "Reshut" part of this tutorial
