- Member of the executive board of SON, 1994-1998
- Member of the executive board of GB-CW, 1999-2000
- Member of the executive board of the Committee of Biochemistry and Biophysics (CBB) of the Royal Netherlands Academy of Arts and Sciences (KNAW), from 1992-2003 (1998-2003 as chairman)
- Secretary of the Section Biochemistry and Biophysics of the Royal Netherlands Academy of Arts and Sciences (KNAW), 1996-1999
- Director of the Centre for Biomembranes and Lipid Enzymology (CBLE), 1989-1993 and 1998-2002
- Chairman of the board of the Institute and Onderzoekschool of Biomembranes (IB), 1999-2001
- Member of the board of the Institute and Onderzoekschool Bijvoet, 1988-present
- Member of the Governing Board of NWO, 2002-present
- Chairman of the Chemistry Section of the KNAW (Royal Netherlands Academy of Arts and Sciences), from January 2008
- Member of many evaluation committees of research organizations abroad
- Member of the selection committee of KNAW fellows, 1996-1999
- Chairman of the evaluation committee of VENI/VIDI/VICI candidates of Utrecht University, 2001-2002
- Vice-chairman of the Forsight Committee (OCW) of Chemistry, Education at High Schools (document: Bouwen aan Scheikunde, SLO, June 2002) 2002
- Vice chairman and member Committee (OCW). New Chemistry at HAVO and VWO (document: Chemie tussen context en concept) 2002-2003
- Member of the Council of the Biophysical Society USA, 2005-2008