Rewind… Errrrch! put on the BRAKES.

I think I may need to start at the beginning before we jump into talking about SNP’s (Single Nucleotide Polymorphisms). I may have gotten a little ahead of myself! So I am going to write a post that hopefully my 8-year-old can understand… and that you can too! Complete with pictures and silly analogies to help him (and all of us) remember!

So let’s get Started!

So we are all made up of CELLS… which is basically a bunch of fluid filled sacks (membranes) that holds a NUCLEUS as well as other cellular components (ie. mitochondria and Golgi Apparatus, etc.) In the NUCLEUS of the cell, you can find Chromosomes.

So what are Chromosomes?

Chromosomes are tightly coiled structures of DNA. There are 23 pairs of chromosomes in human nucleus, for a total of 46 chromosomes in all, which contain DNA (DeoxyriboNucleic Acid).

Chromosomes look like this under a microscope:

Chromosomes (under the microscope)

I like to think of each chromosome as a cook book because it holds the “recipe”~ DNA, that will give the “CAKE” its final Flavor… that would be US, as Humans our flavor…or Traits!

So what is DNA?

DNA is chemical found in both the nucleus of the cell (nuclear DNA) and the mitochondria of the cell (mitochondria DNA) that contains instructions for making proteins out of amino acids. You can think of DNA like the recipe for making a cake, except instead ingredients and words for directions, DNA only uses 4 letters:

A, C, T, G

Each of these four letters represents a “DNA base” or

A= Adenine

T=Thymine

C=Cytosine

G=Guanine

base pairs

And this special “alphabet” goes together in a special way… A always couples (holds hands with ) T and C always couples with G, one letter on each strand of the DNA… giving DNA it’s famous Double Helix, Double Stranded shape.

Groupings of DNA form Genes and a Gene makes a specific protein with a specific function in our body, Proteins are made up of Amino Acids…

So what are Amino Acids?

The easiest way for me to think about Amino Acid are to think of them as individual PEARLS. There are 22 Amino Acids that Humans utilize, essential ones are ones that cannot be synthesized by humans (so they must be obtained through food), and nonessential are synthesized internally. Here is a list of them:

Essential	Nonessential
Histidine	Alanine
Isoleucine	Arginine*
Leucine	Asparagine
Lysine	Aspartic acid
Methionine	Cysteine*
Phenylalanine	Glutamic acid
Threonine	Glutamine*
Tryptophan	Glycine
Valine	Ornithine*
	Proline*
	Selenocysteine*
	Serine*
	Tyrosine*

So what are Proteins?

A protein is a sequence/chain of amino acids, so if amino acids are the pearls then a protein is A STRING OF PEARLS or a PEARL NECKLACE, so to speak. Just as a string of pearls can twist, bend fold and coil on itself, so can a protein and this folding gives the protein it’s charateristic “protein structure” or “protein confirmation”.

So what are Enzymes?

In our oversimplified Biochemistry world here, enzymes are Pac-Man’s or Mrs. Pac-Man’s. Those of you from my generation will hopefully relate to the analogy… for the younger generations you can use “a little guy who chomps on things”. A good way to recognize enzymes is the end in “-ase” like protease, lipase, sucrase or -in (pepsin, rennin). More examples here.

enzyme pac man

So Pac-Man enzymes in the world of our body, speed up or “chomp” on other biochemical molecules… or in the case of a protein, the enzyme bites through the STRING holding the PEARLS together. Enzymes speed up chemical reactions and allow these “strings” to be broken at a much faster rate than if no enzyme would be present. Think of “digesting” your food versus letting it “rot” and decompose, digestion is an accelerated process due to enzymes (specifically those found in your stomach!)