The assembly lines of bio-tech

What genes are? – part 2

After introducing the molecules that store the information of how to create life - the nucleic acids, I will now shortly introduce the way these long chains of information is translated into the small machines that creates life.
In biotechnology we use this machinery to our advantages, to control the way this precious biological data is used.

As you already know, the huge data-base of life is stored in a highly packed ans stable DNA molecules, which can be billions of letter long. These molecules are highly preserved and maintained, and cannot "make life" by themselves. Something have to read the data and use it. The way it is done, is by using a nano scale assembly line, that can read the manuscripts written in the genes and translate it to small machines. Most of the small machinery of life are called proteins, and we will discuss it later.

A large part of the genome contain the information of the machines that use to translate the information in the genome itself. Many small machines are called "transcription factors". These factors control the timing and amount of reading the genome, by binding and modifying, specific locations on the long DNA molecules. The main purpose of these factors is to control the binding of large assembly line, build from several proteins (we call it "complex"), that are used to translate the 4 letters code of the DNA to the 4 letter code of a smaller RNA molecule. This process is called "transcription" since you create the RNA transcript which represent small parts of the DNA code that bear specific functions.




After the RNA is created, it is used as the key to create the functionality of the living cell. RNA have many purposes. First some of the RNA are actually nano-machine by themselves. RNA unlike DNA is not very stable, and its long chines is not packed is a stable helix. The RNA chain can twist and fold, and create a specific form that may have special chemical properties. The folded RNA can be use as a small catalyst to some reactions, like cleaving other RNA. It is also used as part of the transcription complex, and small RNA can be used to cleave other RNA as well, and be part of the transcription control. Finally, most of the RNA are used as a message to further build much more complex machines called proteins. Proteins are the real secret of life, and I will dedicate a different article for them later.

Before being translated into proteins, this messenger RNA is sometimes being modified and changed, parts of it may b cleaved out, and some of its letters are edited. I have to mention it, since you must understand, that not everything that is written in the DNA is translated as is to the RNA message. This message RNA is transferred to a very large protein and RNA complex, a nano-factory called ribosome. This ribosome reads the RNA and translate each 3 letters to one amino-acid. There are 20 amino-acids that the ribosome knows how to connect, and the long RNA message is translated to a long chains of amino acids. Each amino acids have different chemical properties - some are acidic and some are more basic, some can break chemical bonds, and some can assist in creating one, some can bind metals, and so on. Creating this long chains of amino acids with different qualities, is the secret of creating new molecules that can have very different chemical and physical properties, these are called proteins.



In ancient, simple creatures like bacteria, all of these processes are taking place in one large space, inside the cell, which is covered by oily membrane. In more advanced organisms, there are many internal membranes that divide and compartmentalize the cell, so every part of this assembly line is being placed is a dedicated area. the DNA is stored in the nucleus, which protect and maintain the genetic material. In the nucleus the DNA is being transcribed to RNA, and the RNA message is transferred outside of the nucleus, and being translated to proteins on a ribosomes outside of the nucleus.

That's all for now.
lets summarized:
1. The genetic material is being controlled and read by proteins called transcription factors.
2. then a transcription complex assembly line read the DNA is specific locations and create a complementary RNA molecules.
3. RNA can be used as machines by themselves, and help in the processes of controlling the transcription and translation process.
4. The RNA message can go to the ribosome, in which it is being translated to long chain of amino acids, called protein.

Before I'll go into the functions of proteins, I will discuss the way information of the basis to lifr on earth.