Your Body is a Fortress, Part 5 – Your DNA Suitcase

There’s a lot to talk about when mentioning the word, ‘DNA.’

Lots.

One aspect of DNA that I came oh so very close to specializing in (but not quite) is how all that genetic information is packaged. Think about this: stretched end-to-end, you have about six feet of DNA in every cell of your body. Yowzers!

As a reminder:

• Each cell has 46 chromosomes—23 for certain (haploid) cells, like sperm.
• Each chromosome harbors hundreds of genes.
• The human genome (all the genes in your body) numbers about 20,000 to 25,000 genes.
• Human genomes have about 3 million total base pairs. A base pair is a like a rung that forms the ladder, which adds together to form a gene or other DNA coding element.

Not all sections of DNA actually code for traits such as eye color, in other words, not all sections are genes. In fact, genes comprise only about 2% of our genome. I’ll address that aspect another day.

(For lots more interesting info from a superb and reputable source, the Human Genome Project, please click here.)

I was fascinated to learn how all this gunk is wrapped and packaged to fit in such a small space as a cell’s nucleus while maintaining functionality. I mean, geez, I have a few necklaces that I can’t even avoid tangling—DNA packaging is amazing.

I’ll describe, briefly, how it works here, but if you’re like me, and prefer to see pictures as opposed to explanations, go directly to the video below. (Really, I won’t feel bad if you skip the next couple of paragraphs…)

Briefly, here’s how it works, just the basics.
The DNA strands, made up of base pairs, remind me of my aunt’s spiral staircase. These strands wrap around little protein balls called histones. The histones have a lot of cool functions and are made of four types of protein. The balls gather together in sets of eight, the DNA wraps around the 8 balls, and out comes what is termed a nucleosome.

Have I lost you yet? I didn’t think so.

Bed bugs, er, no, those are chromosomes!

After the nucleosome is formed, the structures look kind of like beads on a string. Then these beads start coiling, like a telephone cord—does anyone even have telephone cords anymore? The new structure is called a chromosome and can now fit inside a cell’s nucleus and also be seen by a light microscope (see photo; warning, the linked photo will request a print job).

A parting thought: almost all (99.9%) base pairs (DNA) are exactly the same in all people. If you think you’re alone, or no one else is having the problem you’re facing, I can guarantee you you’re not alone. There’s a very high likelihood that someone shares your hopes, fears, and challenges. You’re not alone.

Thanks for reading along and finding interest in how we pack those six feet of DNA.

Life will never cease to amaze me.

Feel free to email me if you have questions or comments, or leave one here for all to learn from you! What about your body amazes you? There are lots of things to choose from, for sure.

Create a great day!