The Genetic Cookbook
Available in all cells now! Includes all the recipes needed to make a human!
In the spirit of go big or go home, I’m opening with a bold, maybe controversial statement– genes are pretty much the most impressive and important things in our lives.
Because spitting into a 23andMe kit might show us we’re descended from the English royal family and can go and claim our throne?
Possible, but unlikely!
Because they’re responsible for everything from the curly hair we love, to the large nose we don’t?
Yes!
And why we’re more likely to develop diabetes than our neighbor but less likely to develop cancer?
YES, YES, YES!
Talking about genes needs to start with a brief discussion of diet – no, not another article about what we should or shouldn’t eat, but a quick chat about what everyone, but everyone does dine on: micronutrients and macronutrients.
Micronutrients are things like vitamin C, iron and calcium– vital for our survival but needed in really, really small amounts, probably less than 1g every day. In contrast, we eat macronutrients in much larger amounts and we can split these macronutrients into 4 types: carbohydrates (including fiber), fats, proteins and water.
(As each of us is around 60% water, water definitely deserves a blog post all of its own at some point in the future!)
Carbohydrates, whether we’re talking the starch in our bagel or the sugar in our coffee, are used mostly for energy. Gram for gram, fat, whether from crispy bacon or a ripe avocado, gives us about the double the energy as carbohydrates. Equally important though, fats act as homemade bubble wrap, insulating us against heat loss and protecting many of our vital organs.
Which takes us to last but very definitely, NOT least, proteins.
After eating steak or soy beans our gut goes to work, breaking down the proteins in animal- or plant-based foods for our cells then to remake them into the many different human proteins we need.
And oh, do we need proteins – they’re such an amazing family of talented performers!
Showy proteins, for instance, create the bulk of our skeleton and muscles as well as giving us brown eyes and red hair. However, quieter, shyer protein heroes pick up and move oxygen around the body, help destroy germs, control the production of sperm and eggs and pretty much get involved in every single one of the millions upon millions of chemical reactions keeping us alive.
In fact, researchers have calculated (don’t ask me how) that each of our cells contains as many as 40 million protein molecules of around 400,000 different types, phew!
By the way, there’s no test at the end of this article on these numbers and neither can I honestly say that these statistics are likely to be the answer to the biggest question in a “who wants to be a millionaire” run. They’re included only to reinforce the take home message that proteins are incredibly numerous, amazingly important and responsible for an impressive range of different tasks - we truly would be nothing without our proteins!
So, where’s the connection between genes and proteins?
Think of a gene as a recipe that tells our cell how to make one delicious dish, and that delicious dish is one of those thousands of different proteins
Our gene recipes are written in a chemical language called deoxyribonucleic acid, DNA for short.
Chemical language, hmm?
Right now, a huge number of different languages are being used across the planet – estimates suggest greater than 6000 oral (spoken) languages as well as more than one hundred sign languages using not mouth, but hand, body and head movements.
And the tech that I’m using right now to create this post? How on earth do our computers and smart phones allow us to do everything from make a tiktok video to checking our bank balance, using only a language made up of two numbers, zeroes and ones?
A chemical language doesn’t seem quite so strange or intimidating now does it? Instead of a way of communicating that uses sounds, movements or numbers, DNA is just a language that uses a mere 4 chemicals to write all the recipes of life.
Can we do a quick check-in here?
Comfortable that a gene is a recipe instructing our cells how to make a protein?
And each gene is written in DNA, a chemical language?
In that case, time to move from individual recipes to whole cookbooks!
Cookbooks organize their recipes into chapters, and our gene recipes are also arranged in a pretty similar way. Instead of chapters, our genes are collected into chromosomes and each of our cells has an identical cellular recipe book containing 46 of these chapters, I mean, chromosomes.
I liked the way this was going - likening our genes to recipes and collecting the genes/ recipes together into chromosomes/chapters
But now I’m going to have to draw attention to a rather large difference between our cellular recipe book and the one on the kitchen shelf.
Imagine a cook book where each chapter is copied so that straight after the soup chapter, is, oh, the same soup chapter. At first glance each of the two soup chapters looks the same. In both, tomato bisque comes before clam chowder which is followed by Italian wedding soup.
But look closer.
Aha, the first tomato soup recipe needs basil, but the same recipe in the repeated chapter has oregano instead. The clam chowder recipe includes vegetable broth in one recipe but milk in the other and the Italian wedding soup is garlicy in first version but garlic-free in the second!
Two copies of each recipe, almost identical but not quite.
And this happens for the all of the other chapters in this cookbook, two copies of each chapter where the details of the recipes are subtly different in the two different chapter versions.
Our cellular recipe book is like this strange cookbook – each of our cells has the same cookbook but instead of 46 different, individual chromosomes, our genetic cookbook has all our genes organized into 23 pairs of chromosomes.
So, not two chapter 1’s but two almost identical chromosome #1s.
And just like in our strange cookbook, we each have almost two identical versions of all the gene recipes on our two #1 chromosomes.
And the same thing happens with chromosome pair #2 and so on, all the way to and including the 22nd pair of chromosomes
We can thank our biological parents for these two versions of each gene!
Yup, Dad gave us one version of each gene protein recipe and Mom gave us a different version of that same recipe.
Sometimes our cells choose which recipe version to follow and ignore the other version – that’s why we have our father’s nose but our mothers chin!
But these duplicated chromosomes are also a great back up plan.
Because occasionally, when we were a developing embryo, one of those recipes didn’t print properly and now our cells can’t make head nor tail of it. But if we still have one version of the gene that the cell can read? We’ll probably be fine.
So phew, we now know that each of our cells carries an identical genetic cookbook, full of gene recipes, organized into 23 pairs of chromosomal chapters.
And it’s these genes that control the production of pretty much everything that makes us both the same as the human next to us as well as different to that very same human.
Which I think we can agree, makes them a pretty big, make that, enormous, deal!
Want to know more?
For instance, what’s special about that 23rd pair of chromosomes or where do genetic mutations fit into this discussion?
Then let me know via the comments section below or send me an email.
And remember, as always, I’m not here to give medical advice, just to help you have those conversations!
