Saturday, November 22, 2014

The Central Dogma Cafe

Molecular Biology is vitally important for Modern Biology, but can sometimes seem foreign or complicated to new students and the lay person. At the heart of this study of the inner workings of the cell is the transfer of information from DNA to RNA and finally into Protein, which is responsible for a lion's share of activity in the cell.

I have previously tried to explain the importance of, and relationship between, these three molecules by using an analogy of sheet music being read by a musician and instrument to produce sound. While it is a good analogy, I think I have developed an even better one, that of a recipe being used by a chef to prepare a meal. In lieu of writing out a detailed explanation of this analogy (which I may eventually do), I have posted a short video as the first part of my new video series, Life Science in 6 Minutes. 

As it turns out, I was not the first to use the recipe and cooking analogy in molecular biology. At least one other video, courtsey of Bozeman Science, used this analogy. One of my former colleagues also employed this analogy, quiet well in fact, at her blog It's Like Biology. In the remainder of this article, I share ways in which I have expanded upon this analogy, as well as how others have explained the Central Dogma.

Feel free to share your comments both here or on my youtube page. What is your favorite way to explain concepts in molecular biology, microbiology, and synthetic biology?

Extending the Analogy

The idea of a gene as a recipe is not only a sound analogy, but also fits well with how the chromosomal basis of inheritance can be explained. The idea of a gene as a recipe for a protein is useful not only when explaining molecular biology, but also genetics and the chromosomal basis for inheritance. 

Chromosomes are essentially like cookbooks, containing many different recipes. Adult human cells have 46 chromosomes, arranged into 23 pairs. This is akin to have cookbooks for 23 different cuisines, with two slightly different variations for each cuisine. To put this more clearly, imagine you have two Italian cookbooks: they both might have slightly different recipes for meatballs. This is analogous to the two copies of a particular chromosome pair, both with variations on the same gene.

When a particular product is demanded, either a meal in a restaurant or a protein in a cell, only a single recipe is needed at a particular time. While this is an oversimplification on how the production, or expression, of different genes is regulated, it does nicely explain why some traits or recipes are dominant while others are recessive. In some cases, recessive traits are version of a gene that are defective or non active, like a recipe that you don't use because it doesn't taste well. 

Other Examples in the Central Dogma Cafe

Below are several other examples of the cooking analogy as applied to molecular biology. Interestingly, many others have used the idea of making cookies or of the cell as a bakery, as opposed to a generic restaurant. I have to say, I prefer the more visual and delicious idea of cookies!

Explainer: The Central Dogma (It's Like Biology)
A post that uses the recipe / cooking by a former colleague of mine. I particular like the analogy of powdered sugar or other finishing as post-translational protein modification. Her blog, It's Like Biology, has other posts that attempt to give a simple and concise explanation to complicated topics in biology (Like the coordination of cellular behavior, or the structure and function of antibodies).

Basic Concepts: The Central Dogma of Molecular Biology (Sandwalk)
An interesting, although old, blog post by a biochemist, that discusses the use of the phrase 'central dogma': the history of the phrase (developed first by Francis Crick), and how many times it has been 'revised'.

Baking Cookies Describes the Central Dogma (Instructor Exchange)
A very short and concise post, again using the analogy of baking cookies to explanation gene expression.

The Central Dogma - Biochemistry (Amedeo Blog)
A very detailed explanation of the central dogma, fully exploring the analogy and including details of cell structure (the cell as a bakery)

US Government as Central Dogma of Molecular Biology
Another interesting analogy, this time not a bakery but that of the US government. It is an interesting approach, although I have used the government as an analogy in a more specific way (The cooperation of several transcription factors to either activate or repress transcription reminds me of the cooperative and simultaneously adversarial nature of congress). 

The fundamental dogma for beginners...
Not quiet a blog, this is nonetheless an approachable and interactive guide to the central dogma.

Revisiting the Central Dogma in the 21st Century
An interesting article that examines how the central dogma is taught.

The Central Dogma entry on Wikipedia
A straightforward explanation of the central dogma, as can be expected from Wikipedia

I will be returning to more usual posts about synthetic biology and microbiology shortly; the end of the semester is nigh, a busy time for a professor!

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