  Nucleosynthesis in Type I X-ray bursts may involve up to several thousand
nuclear processes. The majority of these processes have only been determined
theoretically due to the lack of sufficient experimental information. Accurate
reaction Q-values are essential for reliable theoretical estimates of
reaction-rates. Those reactions with small Q-values (< 1 MeV) are of particular
interest in these environments as they may represent waiting points for a
continuous abundance flow towards heavier-mass nuclei. To explore the nature of
these waiting points, we have performed a comprehensive series of
post-processing calculations which examine the sensitivity of nucleosynthesis
in Type I X-ray bursts to uncertainties in reaction Q-values. We discuss and
list the relatively few critical masses for which measurements could better
constrain the results of our studies. In particular, we stress the importance
of measuring the mass of 65As to obtain an experimental Q-value for the
64Ge(p,gamma)65As reaction.
