Friday, January 10, 2014

How not to teach biochemistry at

The latest issue of Biochemistry and Molecular Biology Education (BAMBED) has a list of "Websites of Note." One of them is Here's what the BAMBED says about this site ...
You may be impressed or appalled that this site reduces biochemistry to the basics for rote learning. Type biochemistry into the search box associated with Learn on the home page. You will then discover numerous pages created by individual students who have listed prompts and answers to help in their biochemistry studies. Mostly the tabulations of pathways and facts are excellent and accurate. Try Laura Wright's page at The memorization protocol is simple, but effective. After declaring that you have memorized a table you will be tested and at the prompt you answer mentally or on paper, not by entering an answer. You then get to reveal the answer and tell the program whether your recall was correct. Continue as required until all propositions are memorized and can be answered correctly. Pavlov and Skinner would endorse the approach. If a student is pestering with the question "what else can I do to prepare for the exam?" then recommending this site may be the answer.
I was more than a little surprised that an education journal would advertise such a site especially since ASBMB (American Society of Biochemistry and Molecular Biology has come out strongly in favor of concept driven teaching [see ASBMB Promotes Concept Driven Teaching Strategies in Biochemistry and Molecular Biology]. The last issue of BAMBED had a series of articles on the proper way to teach biochemistry.


Better Biochemistry
A concept driven course is incompatible with rote memorization and regurgitation of facts. No respectable teacher—and no reader of BAMBED—should ever send students to the website.

According to ASMBM the The five core concept categories are:
  1. Evolution
  2. matter and energy transformation
  3. homeostasis
  4. biological information
  5. macromolecular structure and function
While I disagree with the way the evolution concept is described [ASBMB Core Concepts in Biochemistry and Molecular Biology: Evolution], I agree that it is important to teach biochemistry from an evolutionary perspective. I'm interested in knowing how biochemistry is taught at other schools and that's why I often look at websites such as where students post what they think is important.

What I see at is appalling. It's clear that students who are posting there have taken courses that focus exclusively on rat liver metabolism and human biochemistry. There's no evolutionary approach visible in any of the student websites. Not only that, many of these students seem to be fixated on something called the "rate-limiting step" in various pathways. Where does that come from? Is there a textbook that teaches like that?

There are people out there who actually think that as soon as an undergraduate finishes a biochemistry course they become an expert. This is the only explanation for all the favorable references to biochemistry websites constructed by teenagers who don't even have an undergraduate degree. (Many of them are directed at pre-med students who are preparing for the MCAT.)

Let's look at a few things that Laura Wright (Oxford University, UK?) says on her page at [Biochemistry - Metabolism 1].

The first box tells us where various pathways are located in the cell. Of course, we're talking about animal cells, not bacteria or plants (photosynthesis isn't mentioned). We learn that protein synthesis takes place in the "RER.". I had to look that up ... it means "rough endoplasmic reticulum." I'd love to know who taught her that. Only a small subset of proteins enter the endoplasmic reticulum. The vast majority of protein synthesis takes place in the cytoplasm.

Students taking a rote memorization course often have to memorize the number of ATP equivalents produced when glucose is oxidized to CO2. This number is 32 ATP equivalents in bacteria and less in eukaryotes. It depends on a number of estimates, especially the number of ATP equivalents produced when electrons from NADH pass through the membrane-associated electron transport system (should be 2.5). Laura Wright says,
32 from malate-aspartate shuttle (heart and liver) vs only 30 from glycerol-3P shuttle (muscle)
This is not what I teach in my textbook but the point is that the "correct" answer on a multiple choice test will not depend on what I think or what Laura Wright thinks. She thinks that the citric acid cycle produces 24 ATP equivalents, I think it produces 20 ATP equivalents, and who know what YOUR professor thinks.

If biochemistry is properly taught from concepts then every student would understand the problems with these estimates and would be able to explain the assumptions behind the calculations.

It's sad to see the sorts of things that students have to memorize. Apparently, many of them have to memorize the names of metabolic diseases (e.g. Niemann-Pick disease) and the symptoms. I think they're also expected to memorize the names of enzymes.

This is not how biochemistry should be taught.