Saturday, 4 May 2013

What up with DNA?

You don't exactly know what DNA is!

So what is DNA, and how does it work?

 DNA, also know as DeoxyRiboNucleic Acid is a molecule. It's a bunch of atoms, stuck together. In the case these bunch of atoms combine to form the shape of a long spiraling ladder . Sort of like this one here. If you've ever studied biology or saw the movie Jurassic Park, you've probably heard , "DNA acts as a blueprint or a recipe for a living thing". But how? How on earth can a mere molecule act as a blueprint for something as beautiful and complex as tree, dog or a dinosaur?  

To answer that question, let's first take a quick look at amino acids. Amino acids are tiny little chemicals inside our bodies which are so important, they are often referred to as the building blocks of life.  

Aspartic Acid (Amino Acid)
Glutamic Acid derivative (Amino Acid)

There's about 20 different kinds of  amino acids, each with there own unique shape. The neat thing about them is that they can be attached to each other ( kinda' like lego's) , to produce an endless variety of larger particles called 'Proteins'. So, amino acids make up proteins. Proteins, along with other chemicals make up living cells. Cells make up tissues.Tissues make up organs. And organs, when they are all put together and functioning, make up living creatures like you and me!

These proteins which make up our bodies, keeping in mind that there are millions of different kinds of them,  they each have to be formed in a perfect shape, in order to function. If they are in the wrong shape, they most likely won't function. That's where DNA comes in.
                                                                                      DNA does a lot of interesting things, some of which we don't fully understand. But one of it's main and well understood functions is to tell amino acids how to line up and form themselves to the perfect protein shape. In theory, if the right proteins are built at the right time and in the right place, everything else from cells to organs and to the creatures will come out just fine.

This here is a simplified model of DNA. It shows us that the steps of a ladder(DNA) are made up of 4 different kinds of chemicals by different colours. If we look at just one half (or one strand) of the model, we can read it's chemical sequence or genetic code from top to bottom, sort of like a book. A single strand of DNA is extremely long. Millions of letters long. It spends most of its coiled up like a noodle of a nucleus of a cell. To help DNA interact with the cytoplasm or the remaining part of the cell other than the nucleus, it converts amino acids (present in the cytoplasm) into proteins. Special chemicals inside the nucleus make 'partial copies' of the DNA code called RNA. These RNA look a lot like DNA but they are shorter and contain only one strand. They are small in shape and this allows them to fit through the tiny pores in the nucleus, from where it goes to the cytoplasm and then into the mouth of another cellular 'organelle' called ribosome. 

Ribosome's are the protein building machines.  They read the RNA code 3 letters at a time, suck amino acids out of their surroundings and stick the newly formed proteins in a chain, according to the RNA code. As the chain grows, it bends and folds and sticks to itself to form a perfectly shaped protein. Every 3 letters of the RNA code tells the ribosome which of the twenty different kinds of should be added next to form a protein.

Once the protein is built, it can then go on to do a number of different things like forming a brand new cell. Then tissue, organ and so on. So the answer to previous question, "What is DNA?". DNA is a molecular blueprint for a living thing. 

This is DNA people.

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