The acids in the nucleus.

What genes are? – part 1

During the 20th century, biologists started to understand the concept of genes, and the way basic chemicals can produce the diversity and phenomena of life. The big explosion of this knowledge was, when scientists proved that the material that is accountable to store and transfer the hidden data of how to create and maintain a living creatures, is coded in a complex, acidic molecules inside our cells nuclei.

These molecules are long chains of simple sugar molecule called ribose, in which each unit in the chain have a slightly different chemical structure. The ribose chains that were found in the nucleus were called Ribo – Nucleic – Acids (RNA) and Deoxy-ribo Nucleic Acids (DNA).
It the 1950’s, scientists understood the structure of these molecules, and from then to now, we gradually figuring out, how these molecules, store and use biological information.

So what is a gene?
A gene is a very old concept in modern biology that is a virtual unit of information that can be passed on to next generations. Today, we usually call to a unit of information written in the DNA language, which can be translated to one protein – a gene. I will explain that sentence later.

The language of life
It is funny to call to the basic molecules of life “nucleic acids”, since they do not have to be in the nucleus. Any creature on earth have DNA and RNA, from the simplest bacteria (which have no nucleus), to mammals and plants. And although the letters of the language are the same, there is huge different in the way different creatures use the universal language of DNA and RNA to store and retrieve information. In its basics, the DNA has 4 “letters” – four different ribose base molecules that can be combined to produce “words”. Part of the huge DNA molecules contains chains of three letter words that can be copied from the DNA to a RNA molecule and then each 3 letter word is translated with sophisticated machinery to long chains of different of amio-acids that build the small machinery of life. More about that later.

Storing the data
The information of how to build the small chemical machines of life is stored in the DNA, a very stable molecule. The DNA has two parallel chains, and each piece of information is actually backed up by the complementary chain. Advanced organisms usually store a backup of the entire gene repertoire in two different molecules. The information is carefully taking care of, by a big inventory of preserving and repairing machines. The DNA is held in every single cell. The information is passed on from generation to generation by duplicating the entire genetic material and passing half of it to the sibling.
We have to understand that most of the data stored in the DNA is not genes themselves, but a huge information on how to read them and when.

Reading the data
Like mentioned before, the data is read by a dedicated machines that knows how and when to translate the information to small molecular machines. Most of the genome contains information on where genes begin and end, when to read them, and in which organ. A lot of nano-machines (that the information to build them is also stored in genes), are used to read, and translate the data to the life processes.

The code of life
When we look on different organisms we can say that most of the gene repertoire was not dramatically changed from the ancient uni-cellular organisms to big animals. Many of life processes are the same. The change in many cases is in the code surrounded the genes, that dictate how and when to read these genes. For example, the hidden different between us and chimps, is probably not in the pool of genes, which is virtually identical, but in the control of how and when to use them.

Complicating things.
When we first solved the way genes are translated to the machinery of life (that will be explained in later articles), we thought that we can easily control the way genes are used, and if we will understand the genome, we will control the processes of life.
That was the beginning of “genetic engineering”. but soon we found out that things are much more complicated.
First, it turn out that most of the genome is not coding to “real genes”. Later we found that a lot of information is not stored in the DNA code, but in other form of data, like RNA, small molecules, and modification of the DNA. We found that genes can be edited after they were transcribed from the genome.
So today we stand with basic understanding of the information of life, but with many questions that have to be solved before we can really “genetically engineer” life.

So what biotechnology and genetic engineering really is?
Well, we do understand some of the way genes work, and we can use the information to manipulate living creatures to do what we want. How do we do so? – on this in later posts...

Let’s summarized:
1. Life’s data is stored in long molecular chains called DNA.
2. DNA is highly maintained and is the genetic material that passed between generations.
3. Part of the DNA contains the information on how to build the life machinery, and some contain the instructions of how to use this data.
4. The way the data is stored and read is very complex and we do not understand the whole picture yet.