Chemical and Physical Biology

Professor Daniel E. Kahne, Co-Head Tutor
Professor Rachelle Gaudet, Co-Head Tutor

The Chemical and Physical Biology (CPB) concentration provides students with a broad foundation in the physical and life sciences. This concentration is designed for students interested in applying quantitative tools, physical concepts, and chemical principles to the study of biology.

Remarkable progress in the last four decades has revealed the atomic structure of proteins, enzymes, and genes, the nature of the genetic code, and how genes can be turned on or off in response to the demands of the environment. As our understanding of fundamental biological processes has increased, so has our appreciation that the focus on information transfer through nucleic acids provides an inadequate basis for understanding living systems. The activities of proteins are regulated by post-translational modifications—chemical changes in protein structure—and are affected by small signaling molecules. Dissecting metabolic pathways and reconstructing cellular networks requires supplementing the traditional arsenal of molecular, genetic, biochemical, and cell biological techniques with advances in chemical and physical methods that make it possible to characterize the state of a biological system under a given set of conditions. Chemical and physical biology provides a link between classical approaches to studying biology and the chemical tools and physical methods required to understand dynamic changes in complex biological systems.

Students who are interested in understanding living systems in detail will require considerable proficiency in mathematics and physics as well as a broad background in both chemistry and biology. In its emphasis on quantitative, physical, and chemical tools, this concentration represents a significant departure from traditional undergraduate programs of study in the biological and life sciences. Our goal is to provide the next generation of life scientists with the background needed to make new advances in the quantitative understanding of living systems. The CPB concentration is intended primarily for students considering careers in research.

All students are required to participate in a tutorial unless engaged in thesis research. Tutorials for students in both Chemical and Physical Biology and Molecular and Cellular Biology are offered by the Board of Tutors in Biochemical Sciences, which was established in 1926. Each tutor holds a PhD and/or an MD degree and meets with her or his students, singly or in small groups, about twice a month to discuss topics tailored largely to individual interests and needs. Tutorial sessions typically consist of readings selected from the primary literature or relevant texts. Mentoring on career choices, the research experience, and other academic issues is a logical extension of the tutorial. The tutorial is not taken for credit and therefore does not appear on the study card or transcript.  A handout that describes the history, goals, and format of the tutorial program is available online.

All students are required to obtain a minimum of one term of laboratory research experience. This requirement may be fulfilled through a project lab course, a term of laboratory research (Chemical and Physical Biology 91r), or research for a senior thesis (Chemical and Physical Biology 99).

A thesis based on laboratory research is required to be eligible for honors in the Chemical and Physical Biology concentration. Students are encouraged to begin thesis research in a laboratory no later than the start of their junior year.


Basic Requirements: 15 half-courses

  1. Required courses:

    1. Life Sciences: Life Sciences 1a (or Life and Physical Sciences A) and Life Sciences 1b, or equivalent.

    2. Molecular and Cellular Biology: Molecular and Cellular Biology 52 and 54.

    3. Chemistry: One half course in general or inorganic chemistry (chosen from Physical Sciences 1, Chemistry 40 or 160, or a suitable equivalent) and one half course in physical chemistry (chosen from Chemistry 60, Molecular and Cellular Biology 56 or 199, Chemistry 161, or suitable equivalent)

    4. Organic Chemistry: Chemistry 20 and 30, or Chemistry 17 and 27, or equivalent.

    5. Mathematics: Mathematics 19a and 19b, or 21a and 21b, or Applied Mathematics 21a and 21b.

    6. Physics: Physics 11a and 11b or 15a (or 16) and 15b, or equivalent.

    7. Three upper-level courses in the natural sciences, engineering, and/or mathematics. Courses that meet this requirement include any 100-level chemistry, molecular and cellular biology, or physics course. Other courses that meet this requirement are posted here.

    8. Students who do not write a thesis based on laboratory research (see item 3 under Requirements for Honors Eligibility) must take one upper level project lab course (such as Life Sciences 100r, Chemistry 100r, 135 or 165) or enroll in one term of Chemical and Physical Biology 91r.

  2. Tutorial: Required of all concentrators in sophomore and junior years unless engaged in thesis research. Tutorial sessions are non-credit (and therefore do not appear on the study card or transcript), take place approximately twice per month, and typically consist of readings selected from the primary literature or relevant texts. A handout that describes the history, goals, and format of the tutorial program is available online.

Requirements for Honors Eligibility: 16 half-courses

  1. Required Courses: Same as Basic Requirements.

  2. Tutorial: Same as Basic Requirements.

  3. Thesis: A thesis based on independent laboratory research is required for honors eligibility. Students should therefore enroll in two terms of Chemical and Physical Biology 99, one of which counts towards the upper-level course requirement (see item 1h, above).


Professors Dan Kahne, Rachelle Gaudet, and Erin O’Shea (on leave 2009-10)  are the primary advisers for CPB concentrators. Dr. Tom Torello is also available to concentrators and pre-concentrators to provide guidance on course selection, laboratory research, and the fulfillment of concentration requirements. Please call 5-4106 or email to schedule an appointment with either Tom Torello or one of the head tutors. Advising notes for CPB concentrators are also available online.

For up-to-date information on advising in Chemical and Physical Biology, please see the Advising Programs Office website.


A tutorial reference library is housed in the Student Affairs Office at 7 Divinity Avenue, and contains books and journals frequently used for tutorial reading.


For more information about the CPB concentration, visit and click on the link for Chemical and Physical Biology under the "concentrations" tab. The CPB Student Affairs Office is located in Sherman Fairchild Room 195, 7 Divinity Avenue (617-495-4106).


Non-exempt areas:

Exempt areas:

Foreign Cultures

Quantitative Reasoning

†Historical Study A

Science A

†Historical Study B

Science B

†Literature and Arts A

ONE of the areas marked †.

Literature and Arts B


†Literature and Arts C


Moral Reasoning


Social Analysis


For more information on fulfilling the Core requirement, see the Core Curriculum Requirement.

All students—regardless of concentration—planning to graduate under the requirements of the Program in General Education must complete one letter-graded course in each of the eight categories in General Education. The Class of 2013 is the first to enter the College under these requirements. Students who entered Harvard College in September 2008 or earlier are expected to fulfill the requirements of the Core Curriculum, but will be permitted to switch to the Program in General Education if such a change is possible and advisable given their overall schedule and plan of study. For more information on the requirements of the Program in General Education and the possibility of switching to it, please see The Program in General Education in Chapter 2 and the General Education website.


Number of concentrators as of December





Chemical and Physical Biology




CPB + another field




Another field + CPB