I am always amazed how much people underestimate their ability to understand science. This is partly due to established scientists speaking in their own “science – speak.” One of the best teachers in history was a man named Michel Thomas who was a language educator – most famous for a BBC documentary where he taught French to high school students in 5 days. He said that it is the teacher’s responsibility, not the student’s aptitude that makes the difference. Put another way – you have the aptitude and ability to learn things that you might not think you do.
In this short post, you will know all you need to know about genetics to understand the science that follows in further posts.
Let’s start with a 30,000 ft view. All of your bodies cells have chromosomes which package your DNA to fit into the cell – you inherit 23 chromosomes from your father and 23 from your mother. These chromosomes hold all of your DNA. DNA is your genetic information, its the book and manual of what you look like and how your body functions. The DNA needs chromosomes because there is so much information that if it was not tightly packed into chromosomes it wouldn’t fit in your cells! It’s like trying to package a month’s worth of clothes into a regular suitcase. You better use all kinds of folding techniques to fit it in there. Chromosomes are that and then some, they hold, twist, and pack the DNA to fit – in fact if you took DNA and stretched it out it would be 6 ft tall!!
A gene is a segment of DNA. Your body reads your genetic code and makes the proteins that your body is made of. The language of this book of DNA is actually made up only of four letters or nucleotides: A, C, G, and T. I hope to get into the significance of this number 4 in another series of posts. Identical twins would have an exact duplication of this sequence of 4 letters. For the rest of us, we have differences in the sequences (genes) that account for our differences. Along with these differences, that make us taller, darker, have bigger eyes, etc there are other differences also that can affect the way our bodies process nutrients, detoxify our bodies, and a whole host of other biological processes.
The science of nutrigenomics is mostly concerned with this sequence of letters or nucleotides. We will concern ourselves with 3 variations. Before introducing what they are called, let’s describe them because you now know enough to understand them. There is one variation (1) where there is a change in one of the 4 letters or nucleotides we just mentioned. There are sometimes variations where (2) there is a large section of nucleotides missing, and (3) there are variations where additional nucleotides are added. The variations we will concern ourselves with are called SNP’s (single nucleotide polymorphisms), Del (as in deletions), and Ins (as in Insertions) variants.
That is all you need to know for now. To review – chromosomes package the DNA you have inherited from your parents. Individual segments of this DNA made up of a sequence of nucleotides will make up a gene that will code for some specific function, and in these sequences you can have variations of which we listed the main 3 that we will be concerned about SNP’s (pronounced snips that have one nucleotide different), Ins (insertion variation where a sequence of nucleotides have been added), and Del(where a sequence has been deleted).
The movie Gattaca was called that because of the genetic themes. The ethical themes raised by this movie will be dealt with here as well later on. The word GATTACA is made up of 4 nucleotides. A SNP of GATTACA would be AATTACA. An Ins would be GAGAATTACA. A Del would be TACA. Now that you understand each of these genetic variations, you are ready to understand some groundbreaking studies that allow us to examine the effect of these on your health and how that pertains to your nutrition.
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