Biophysics of Excitable Cells (PHYS*2030)

Code and section: PHYS*2030*01

Term: Winter 2021

Instructor: Leonid Brown


Course Information


Name Office Email
Leonid Brown MacNaughton 325


Name Office Email
Richard Parg MacNaughton 537
John (Atkinson) Simmons MacNaughton 537

Lectures and Tutorials


Monday, Wednesday, Friday 11:30 – 12:20, Synchronous (AD-S; VIRTUAL)


Section 1: Tuesday 8:30 – 9:20, Synchronous (AD-S; VIRTUAL)
Section 2: Monday 2:30 – 3:20, Synchronous (AD-S; VIRTUAL)
(NOTE: no tutorials will be held in the midterm week and the week after, weeks 7-8)

Office Hours

By appointment, on-line only, please email Richard, John, or Leonid.

Course Website

Zoom links, lecture notes, problem sets and solutions, tutorial problems, and other supplementary material will be available on the Courselink.

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)


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

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 Assignment/Tutorial
Week 1: Jan 11-15 Introduction to the course
Chapter 1: Membrane structure/function
Begin Chapter 2: Diffusion, Fick's Law, Permeability
Tutorial 1 - review of the relevant mathematics
Week 2: Jan 18-22 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 25-29 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: Feb 1-5 Continue Chapter 4: Electric current, mobility, Nernst equation, Donnan equilibrium, equivalent circuit of a membrane, Goldman-Hodgkin-Katz equation Tutorial 4
Week 5: Feb 8-12 Chapter 5: Current injection; the nerve impulse, voltage clamps and ionic currents Tutorial 5
Problem Set 1 Due on Monday, Feb 8
Reading Week: Feb 15-19 NO CLASSES  
Week 6: Feb 22-26 Chapter 6: Synaptic transmission
Midterm Review
Tutorial 6 - Midterm Review
Week 7: Mar 1-5 Chapter 7: Ion channels
Midterm Exam (Wednesday, Mar 3 in class)
Problem Set 2 Due
on Monday Mar 1

No tutorial
Week 8: Mar 8-12 Chapter 7: Ion channels continued
Begin chapter 8: Vision, the invertebrate eye
No tutorial
Week 9: Mar 15-19 Continue Chapter 8: Vision, the invertebrate eye Tutorial 7
Week 10: Mar 22-26 Continue Chapter 8: Vision, the vertebrate eye Problem Set 3 Due
on Monday, Mar 22

Tutorial 8
Week 11: Mar 29 – 31 Chapter 9: Hearing; No class Apr 1 - holiday Tutorial 9
Week 12: Apr 5-12 Chapter 10: Olfaction and taste
Exam review
Extra class Apr 12 rescheduled from Apr 1
Problem Set 4 Due on Monday, Apr 12
Tutorial 10 – Exam review

Course Assessment

Assessment Details Weight
Problem Sets 4 total, 8% each 32%
Midterm March 3, in class, on-line 28%
Final Exam April TBA, on-line 40%
Total   100%


Tutorials will be held every week (except for the weeks 7 and 8). The tutorials are 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 8
  • Problem Set 2: March 1
  • Problem Set 3: March 22
  • Problem Set 4: April 12

The Problem Sets should be submitted ELECTRONICALLY on the dates indicated above, by 4.30 PM, to the drop-box set up on the Courselink.

Midterm examination

Wednesday, March 3rd, in class (on-line). 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

April TBA, on-line. 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 a justification if you wish to submit your assignment later than two days after the deadline.

Other Information and 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.

Academic Consideration

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. See the undergraduate calendar for information on regulations and procedures for Academic Consideration.

Academic Misconduct

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 discourages misconduct. 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.

The Academic Misconduct Policy is detailed in the Undergraduate Calendar.


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For more information, contact SAS at 519-824-4120 ext. 56208 or email or see the website:

Course Evaluation Information

Information about the date and time of the course evaluation will be made available during the semester.

Drop date

The last date to drop one-semester courses, without academic penalty, is April 12, 2021. For regulations and procedures for Dropping Courses, see the Undergraduate Calendar.


Please note that the ongoing COVID-19 pandemic may necessitate a revision of the format of course offerings and academic schedules. Any such changes will be announced via CourseLink and/or class email. All University-wide decisions will be posted on the COVID-19 website and circulated by email.


The University will not require verification of illness (doctor's notes) for the Fall 2020 or Winter 2021 semesters.