This training grant will continue to provide support for graduate students at U C Berkeley working in Molecular Biophysics. This support enhances the opportunities and experiences of students in this field, and hence stimulates students to enter it. It also supports our Structural and Quantitative Biology seminar program, bringing prominent researchers to Berkeley to present their work and meet students and faculty. The students in this training program take a small number of core courses (almost all during the first two years of study), which are centered on contemporary problems in molecular biophysics and the methods used for analysis of systems at the molecular level. Additional course offerings that provide a firm grounding in physical chemistry and in molecular biology, providing the basis for linking these to examine the molecular basis for biological behavior. Specialized courses are also available that focus on single methods, such as x- ray diffraction or NMR spectroscopy, that are relatively widely used. All students supported through this grant also take a course that addresses issues in the ethical conduct of research. Entering MCB and Biophysics students do rotations in labs, and then choose a research director. In chemistry during a 6-8 week period at the beginning of the first semester during students visit with faculty to learn about projects, and then join a lab mid-semester. Students also serve as teaching assistants during the first years (the number of semesters is determined by the department). Regular attendance at seminars (particularly those in Structural and Quantitative Biology) is expected throughout the graduate career. Research projects span many areas in the study of biological systems at the molecular level. This includes determing structures to understand the function of proteins, protein complexes, RNAs, ribonucleoprotein complexes (including the ribosome one of the largest and most important of such complexes). Three labs now actively involved in single molecule spectroscopy and manipulation experiments, and other labs collaborate with them. Students bridging between labs and methodologies are given increased priority for support through this training program. There is a very broad representation of methods used in the labs of the training faculty, with exceptional facilities for x-ray diffraction, NMR and EM as well as single molecule experiments.