| Welcome to Exploration's mini Biology lecture for the day. Don't worry, this won't hurt. Much. We promise. OK, so here's the deal: living things are very, very well-organized and well-oiled pieces of natural machinery. An animal body processes food to harvest energy, sends complex internal messages, and maintains a consistent internal environment so that all the parts of the body can function at their best. A body is very complex, but behind it all is something quite simple: genetics. The cells in a body are a bit like men in an army: there are lots of them, and they can do a whole variety of things, but what they really need to function effectively is something that acts as a leader, something to tell them what to do. In a body, those are called genes. (genes --> genetics, stuff about genes.) The way genes work is relatively simple (unless you're in Advanced Bio class, I'll bet) but quite elegant. They are templates that contain coded instructions for making large molecules called protiens. These protiens are pigments for hair and eyes and skin, messengers that can travel throughout the body, enzymes that help the body beak things down, and myrad other things. Protiens just about do it all. But the trick is, like I said, that the instructions the genes contain for making protiens are coded. They have to be coded so that the instructions can be read over and over again, re-used to make millions of copies of all of the protiens that the body needs in order to function correctly. (Protiens wear out: they must be refreshed and replaced regularly.) So, the idea of how genes do their work in the body is not so complicated: gene gets decoded, gene template translted into a protien, protien has a function that helps keep the body organized and coordinated. But the process of decoding and translating the stored information is not quite so simple. First, a gene is written in code, using a four-letter "alphabet": A,T,G, and C. These letters stand for four special molecules which really do function like a four-letter alphabet: they are read by threes, forming three letter "words," like AGC, TGA, AAT, and so on. Now, these are nonense to us, but to our body those speak volumes: each three letter word stands for an amino acid. These amino acids are the building blocks of all protien molecules, so what the genes really represent is a sort of step-by-step instruction book on how to build specific protiens ("first, put this amino acid over here, and then that one over there..." and so on). For all of that to work, you need three things: 1) a very clear "decder key" to make sure you know which word stands for which amino acid. 2) something that can take the instructions and actually build the needed protiens. 3)some way to get the instructions to whatever will be building the protien. This is rapidly becoming quite a project, here. Luckily, we have the proper "decoder key" and we have something that can build the protien--that's called a ribosome. It's the construction worker in this picture, working away, building protiens. To get the instructions to the ribosome, you first have to do a few things: you have to unwind the DNA strand which is the part of the gene that codes for the protien you want, then you have to make a temporary copy of the coded instructions it contains (are we getting tired yet?). Once you've done that, the ribosome can do its job, albiet with a little help: before it can build a protien, it need the amino acids it is supposed to use (small detail, quite important). So there is a little fleet of carrier molecules called t-RNAs that ferry amino acids to and fro. There are perhaps several dozen different types of t-RNA, each one designed to carry one of about twenty amino acids which the body will need to use. Each type of t-RNA has a little "ID tag" that identifies which ammino acid it's carrying, and this matches with the instructions the ribosome is using such that they hook together like lock and key and fit into the right place. The ribosome strings together each sucessive amino acid that matches with the temporary copy of the instructions which it is reading. Finally, we are almost there. If you are the mathematical type, you may have figured out that if you use four "letters" and read them in groups of threes, you will get more possible combinations than I estimated there were amino acids. This is no problem: sometimes more than one "word" will stand for the same amino acid. This gives the body a bit of a back-up plan. Also, a few three-letter words are not associated with an amino acid. They are "blank," so the ribosome reads them as a STOP command that tells it when the protien is finished. Once the ribosome comes to a STOP command, it no longer adds amino acids, and it releases the protien-to-be. There are a few special enzymes that clip the future protien and sometimes help fold it into its proper shape, and then our protien is ready to do its job--and that, friends, is how you make a protien. *sigh of relief* OK, I know. You weren't expecting biology class. You were expecting something to do with God. Here it comes. This whole process I told you about is incredibly complex: it has, in essence, a code book which is set down and encoded in just the right sequence onto a strand of DNA to map out how to make important protiens. Scientists have actually worked out most of this code-book and you can find it printed in a table in most biology texts. Not only is there this amazing doce-book, there is a factory-floor process involving a whole slew of specialized molecules used to actually construct the protien. But how did this come to be? Molecules don't just organize themselves. What, one day did a molecule just sit up and say, "hey guys, I'm DNA and I'm gonna be in charge from now on, so this is what we're gonna do..."? It's a little preposterous. Everything alive on Earth, from the merest bacterium on up, relies on this system of genetics. But I ask again, how did this system ever get organized? What could have caused it to be in a world where things like to get more disorganized the longer you leave them alone? That's my point: this system reminds me of a careful factory production plan drawn up by someone capable of rational thought. Now, I am not--repeat not--getting into the Creation/Evolution debate here. I plan to talk about that elsewhere. What I say here would be the same if we were all simply created as-is, genes and all, or whether we evolved from the first single-celled organism where the system of genes-to-protien was used. It is entirely possible that the system in question arose entirely on its own through chance, but it just seems so...well...improbable that it would have ever actually happened. It really does give me the feeling that there is Someone out there who weitghted the dice in our favor. Genetics is a complex system, it seems "too good to be true"...but here I am writing, and there you are reading. Go figure. Mabe there's Something out there after all.... Biology and Religion can be good friends. What do you think? Send feedback: Email Redwing Back to Discussion of God Back to Philosophy Homepage Back to Exploration Homepage |
| 2) Go Figure: Genetics |