Of Tangles and Balls
My struggles to untangle the cords of my earphones often reminds me of my grandma. She had no earphone cords to worry about, but she had yarn, lots of it. Except her yarn was never tangled because she meticulously finger-wrapped any loose yarn into tight balls. It sure requires planning and effort to prevent strings of any kind from becoming a useless mess.
Sailors, gardeners, knitters, manufacturers and those with lovely long hair can all attest to this truth. When I learned about DNA, an incredibly long, thin and sticky string that functions as a 3-dimensional instruction manual, I wondered what prevents it from hopelessly tangling up. As it turns out, DNA takes the tangle-prevention strategy to a whole new level.
Inside the tiny nucleus of human cells, this 6 ft (2 m) long double-stranded string is sectioned, wrapped, and rolled to fit into a space of just 6 microns across. And would you know it, the string wraps around molecules (histones) into tiny balls (nucleosomes) like beads on a string! Before cell division, these balls then wrap around each other and stack up in super-coils to protect the pages of the most complex and valuable book of life. Unrolling the DNA strands for copiers to read the information requires a different set of machinery.(1) But that is a story for another day. Below a 3-D animation, How DNA is Packaged, from the DNA Learning Center that gives a glimpse into this fascinating process.
What's more, this process needs a precision control mechanism. For example, wrapping around the wrong amount of balls will cause defects in DNA replication, because it will be either too easy or too difficult for the copier machines to run along the string. So following cell division, the instructions for making these balls are sent to the “shredder’ so that no new balls can be made during the life of the cell. Since errors in the wrapping process will eventually lead to cell death, scientists are now exploring the possibility of using this information to kill cancer cells. (2) It is not an easy fix though, as the cell’s complex signaling and control systems are still beyond our understanding. (3)
The remarkable multi-level packaging of DNA testifies to the creative ability of the Designer. His attention to detail is on a scale grander than what we can ever imagine. It is a reminder that there is nothing too big or too small for Him, and that includes our problems and us. Jesus once said, ‘“And why are you worried about clothing? Observe how the lilies of the field grow; they do not toil nor do they spin, yet I say to you that not even Solomon in all his glory clothed himself like one of these. But if God so clothes the grass of the field, which is alive today and tomorrow is thrown into the furnace, will He not much more clothe you? You of little faith!”
(Matthew 6:28-30 NASB)
2. http://our.oasis.unc.edu/public_html/hhmi/hhmi- ft_learning_modules/2011/proteinsmodule/histones/research.html