We investigated the influence of the projectile size and energy using Au n q+ clusters (5<n<400, 1<q<4) impacting on a glycine target with a 19q–34qkeV energy range. We show that both CN − fragment and Gly − molecular ion yields are equivalent for projectiles with n>9 and increase with the energy per projectile atoms. A maximum yield of 0.5 (50%) for both CN − and Gly − was obtained with the Au 400 4+ projectile at 136keV total energy. For Gly − , the yield enhancement is linear for Au n when n>5. Trends for the CN − fragment are different. A nonlinear yield enhancement proportional to n 3 is observed for Au n when n<9.