Chemical and Physical Biology

Professor Adam Cohen, 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. Tutors hold a PhD and/or an MD degree and meet with their 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 my.harvard crimson cart 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 91), or research for a senior thesis (Chemical and Physical Biology 99A and B). 

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: 16 courses (64 credits)

  1. Required courses
    1. Life Sciences (2 courses): Life Sciences 1a (or Life and Physical Sciences A) and Life Sciences 1b, or equivalent. 
    2. Biology (2 courses): MCB 60 and one additional course selected from MCB 63, MCB 64, MCB 65, MCB 68, or MCB 80. 
    3. Chemistry (2 courses): One course in general or inorganic chemistry (chosen from Physical Sciences 1, 10 or 11; Chemistry 40 or 160; or a suitable equivalent) and one course in physical chemistry (chosen from Chemistry 60, Molecular and Cellular Biology 65 or 199, Chemistry 161, or a suitable equivalent). 
    4. Organic Chemistry (2 courses): Chemistry 20 and 30, or Chemistry 17 and 27, or equivalent. 
    5. Mathematics (2 courses): Mathematics 19a and 19b, or 21a and 21b, or Applied Mathematics 21a and 21b. 
    6. Physics (2 courses): One course in mechanics (chosen from Physics 16 or 15a, Physical Sciences 2 or 12a, or Applied Physics 50a), and one course in electricity and magnetism (chosen from Physics 15b, Physical Sciences 3 or 12b, or Applied Physics 50b). Students who do not take at least one course at the level of Physics 15 or 16 or Physical Science 12 must take a computational course as one of the upper level courses (see item 1g, below) chosen from CS 50 or 109; Applied Math 111, 115 or 126; MCB 111, 112, 131, or 199; or other computational class approved by the Head Tutor. 
    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 or Chemistry 100r) or enroll in one term of Chemical and Physical Biology 91. 
  2. Tutorial: The tutorial program is an important component of the concentration. It provides a mechanism for students to engage in mentorship relationships with the MCB faculty and members of the Board of Tutors in Biochemical Sciences. The goals are to (1) provide opportunities for discussions about science and its role in the larger community, (2) provide students with the foundation to apply their education and the scientific method to life outside of the classroom and Harvard and (3) advise and inform students on curricular and pre-professional choices. The tutorial is a non-credit program that spans the whole length of time the student is part of the concentration.A handout that describes the history, goals, and format of the tutorial program is available online

Requirements for Honors Eligibility: 16 courses (64 credits) 

  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 1g, above). 
Professors Adam Cohen and Rachelle Gaudet and Dr. Dominic Mao are available to concentrators and pre-concentrators to provide guidance on course selection, laboratory research, and the fulfillment of concentration requirements. 
A tutorial reference library is housed in the CPB Undergraduate Office at 7 Divinity Avenue (95 Sherman Fairchild building), which contains books and hard copies of past senior theses (thesis titles from 2011-present can be viewed here). Four rooms in the upper level of the undergraduate office are used by concentrators for tutorial meetings and as study spaces. 
The Co-Head Tutors for the Chemical and Physical Biology concentration are Professors Adam Cohen and Rachelle Gaudet, and the Concentration Adviser is Dr. Dominic Mao ( or 617-495-4106). Visit or contact Dr. Dominic Mao ( or 617-495-4106) for more information. 
Number of Concentrators as of December
Concentrators 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019
Chemical and Physical Biology 33 65 59 57 63 48 42 42 50 45 39 40
Chemical and Physical Biology + another field 22 0 0 1 0 0 0 0 0 1 2 4
Another field + Chemical and Physical Biology 0 0 0 0 0 0 0 1 1 1 2 1