Biophysics of Excitable Cells (PHYS*2030)

Code and section: PHYS*2030*01

Term: Winter 2022

Instructor: Leonid Brown


Course Information

Course Calendar Description

An intermediate biophysics course with special emphasis on the physical properties of nerve cells and of biological transducers such as the ear and the eye.

Prerequisite(s): 1.00 credits in physics (excluding PHYS*1020, PHYS*1600, PHYS*1810)
Credit Weight: 0.5



Leonid Brown
MacNaughton 325

Teaching Assistants

Marie Pinto

Philip Drewniak

Office Hours

By appointment, please email your TA or Leonid.

Lectures and Tutorials


Monday, Wednesday, Friday 9:30 – 10:20 AM, THRN 1307


Section 1: Tuesday 04:30 - 05:20 PM, MCKN 224
Section 2: Monday 03:30 - 04:20 PM, MCKN 227

(NOTE: no tutorials will be held in the midterm week and the week after, weeks 7-8)

NOTE: Both lectures and tutorials will be delivered in Synchronous (AD-S; VIRTUAL) mode until at least January 24th, via Zoom and Teams, see the Courselink to join. Stay tuned for the announcements regarding any changes in the delivery mode!


The main objectives of this course are to provide a basic understanding of the physical phenomena underlying nerve and membrane activity, and to illustrate how these phenomena are applied to different types of excitable cells.

By the end of this course students will be able to…

  1. Describe how physical principles influence the structure and function of excitable cells.
  2. Illustrate how physical phenomena can be applied to different types of excitable cells.
  3. Solve numerical problems using circuit analysis with various components including membrane resting and action potentials, membrane conductance and current flowing through cell membranes under different physiological conditions.
  4. Explain membrane and nerve activities with reference to the relevant underlying physical phenomena that give rise to them.
  5. Analyze how the principles of diffusion and electricity apply to biological membranes and individual nerve cells and how these result in cell resting and action potentials under different conditions.
  6. Apply the appropriate physical models to solve numerical problems describing sensory functions including hearing, vision, olfaction and taste.
  7. Generate simple circuit models to describe excitable cell membranes for excitable cells specific to the sensory systems.
  8. Compare and contrast the mechanisms underlying sensory functions of vision, hearing, olfaction and taste.

Learning Resources

Course Website

Lecture notes, problem sets, and supplementary materials will be available on Courselink.

Required Text

  • "Biophysics of Excitable Cells" by G.H. Renninger, U. of G., 2003.
    Available from the UG Bookstore.

Recommended Texts

  • "From Neuron to Brain" by J.G. Nicholls et al. (Library: QP 355.2.K83 2001)
  • “Principles of Neural Science" by E.R. Kandel et al. (Library: QP 355.2.P76 2013)


Week Topics Assessment/Tutorial
Week 1: Jan 10-14 Introduction to the course
Chapter 1: Membrane structure/function
Begin Chapter 2: Diffusion, Fick's Law, Permeability
Tutorial 1 - review of mathematics
Week 2: Jan 17-21 Continue Chapter 2: Diffusion, Fick's Law, Permeability, active transport
Begin Chapter 3: Coulomb's law, Electric potential, Work, Electric fields, Capacitance
Tutorial 2
Week 3: Jan 24-28 Continue Chapter 3: Coulomb's law, Electric potential, Work, Electric fields, Capacitance
Begin Chapter 4: Electric current, mobility, Nernst equation, Donnan equilibrium
Tutorial 3
Week 4: Jan 31 - Feb 4 Continue Chapter 4: Electric current, mobility, Nernst equation, Donnan equilibrium, equivalent circuit of a membrane, Goldman-Hodgkin-Katz equation Tutorial 4
Week 5: Feb 7-11 Chapter 5: Current injection; the nerve impulse, voltage clamps and ionic currents Tutorial 5
Problem Set 1
Due on Monday, Feb 7
Week 6: Feb 14-18 Chapter 6: Synaptic transmission
Midterm Review
Tutorial 6 - Midterm Review
Week 7: Feb 28 – Mar 4 Chapter 7: Ion channels
Midterm Exam (Wednesday, Mar 2, Online or Room TBA)
Problem Set 2
Due on Monday Feb 28;
Midterm is on Wednesday, Mar 2;

No tutorial
Week 8: Mar 7-11 Chapter 7: Ion channels continued
Begin chapter 8: Vision, the invertebrate eye
No tutorial
Week 9: Mar 14-18 Continue Chapter 8: Vision, the invertebrate eye Tutorial 7
Week 10: Mar 21-25 Continue Chapter 8: Vision, the vertebrate eye Problem Set 3
Due on Monday, Mar 21

Tutorial 8
Week 11: Mar 28 – Apr 1 Chapter 9: Hearing Tutorial 9
Week 12: Apr 4-8 Chapter 10: Olfaction and taste
Exam review
Problem Set 4
Due on Friday, Apr 8

Tutorial 10 – Exam review

Course Assessment

Assessment Details Weight
Problem Sets 4 total, 8% each 32%
Midterm Mar. 2, Room TBA 28%
Final Exam April 19, 2022, 11:30am, Room TBA 40%
Total   100%


Tutorials will be held every week (except for the weeks 7 and 8). The tutorials are an important part of the course, since they provide practice and assistance with solving numerical problems.

Problem Sets

These contain mainly numerical problem-solving questions showcasing the application of physics to biological membranes and sensory systems. There will be four (4) problem sets worth 8% each and have deadlines throughout the semester:

Problem Set 1: February 7
Problem Set 2: February 28
Problem Set 3: March 21
Problem Set 4: April 8

The Problem Sets should be submitted ELECTRONICALLY on the dates indicated above, by 11 PM, to the drop-box set up on the Courselink.

Midterm examination

Wednesday, March 2, in class or online, Room TBA. In the first half of the course, physics principles are reviewed with specific application to cell membranes. The midterm is worth 28% of the total course grade.

Final examination

Tuesday, April 19, 11:30 am, location TBA. In the second half of the course, sensory systems are discussed in detail with the application of physics phenomena and circuit models. The final exam is cumulative as the course builds throughout the semester and has both numerical and qualitative questions. The final exam is worth 40% of the total course grade.

Late Assignments

The penalty for late assignments is a 20% deduction per day, to a maximum of two days. You will be given ample time to complete your assignments; accordingly, you will be required to provide medical documentation if you wish to submit your assignment later than two days after the deadline.

Course Policies

Course Policy regarding use of electronic devices and recording of lectures

Presentations which are made in relation to course work—including lectures—cannot be recorded or copied without the permission of the presenter, whether the instructor, a classmate or guest lecturer. Material recorded with permission is restricted to use for that course unless further permission is granted.

University Policies

Email Communication

As per university regulations, all students are required to check their e-mail account regularly: e-mail is the official route of communication between the University and its students.

When You Cannot Meet a Course Requirement

When you find yourself unable to meet an in-course requirement because of illness or compassionate reasons please advise the course instructor (or designated person, such as a teaching assistant) in writing, with your name, id#, and e-mail contact. The grounds for Academic Consideration are detailed in the Undergraduate and Graduate Calendars.

Drop Date

Students will have until the last day of classes to drop courses without academic penalty. The deadline to drop two-semester courses will be the last day of classes in the second semester. This applies to all students (undergraduate, graduate and diploma) except for Doctor of Veterinary Medicine and Associate Diploma in Veterinary Technology (conventional and alternative delivery) students. The regulations and procedures for course registration are available in their respective Academic Calendars.

Copies of Out-of-class Assignments

Keep paper and/or other reliable back-up copies of all out-of-class assignments: you may be asked to resubmit work at any time.


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When accommodations are needed, the student is required to first register with Student Accessibility Services (SAS). Documentation to substantiate the existence of a disability is required; however, interim accommodations may be possible while that process is underway.

Accommodations are available for both permanent and temporary disabilities. It should be noted that common illnesses such as a cold or the flu do not constitute a disability.

Use of the SAS Exam Centre requires students to book their exams at least 7 days in advance and not later than the 40th Class Day.

For Guelph students, information can be found on the SAS website

Academic Integrity

The University of Guelph is committed to upholding the highest standards of academic integrity, and it is the responsibility of all members of the University community-faculty, staff, and students-to be aware of what constitutes academic misconduct and to do as much as possible to prevent academic offences from occurring. University of Guelph students have the responsibility of abiding by the University's policy on academic misconduct regardless of their location of study; faculty, staff, and students have the responsibility of supporting an environment that encourages academic integrity. Students need to remain aware that instructors have access to and the right to use electronic and other means of detection.

Please note: Whether or not a student intended to commit academic misconduct is not relevant for a finding of guilt. Hurried or careless submission of assignments does not excuse students from responsibility for verifying the academic integrity of their work before submitting it. Students who are in any doubt as to whether an action on their part could be construed as an academic offence should consult with a faculty member or faculty advisor.

Recording of Materials

Presentations that are made in relation to course work - including lectures - cannot be recorded or copied without the permission of the presenter, whether the instructor, a student, or guest lecturer. Material recorded with permission is restricted to use for that course unless further permission is granted.


The Academic Calendars are the source of information about the University of Guelph’s procedures, policies, and regulations that apply to undergraduate, graduate, and diploma programs.

Academic Calendars