mRNA

mRNA stands for (m) messenger (R) rybo (N) nucleic (A) acid  although usually, the r and n stay together making rybonucleic.  You can see that this is just DNA with the D chucked away and the m stuck on.

There are four bases in DNA strands.  They are G,C,A,T. 

C = Cytosine

G = Guanine

T = Thyamine

A = Adenine

C ALWAYS BONDS TO G

T ALWAYS BONDS TO A

What happens in mRNA is that certain pieces of information in the DNA need to be replicated They are replicated in the cytoplasm. The large strands of DNA cannot get out of the cell though, and so need to be taken by something smaller. What happens is that a single strand of DNA comes and copies the pieces of information that it needs.

To do this, the DNA double helix unravels and allows a strand of messenger RNA to cme between them.  It copies the side of the information it needs.

There is a strange thing though, that is that the messenger does not have T.  But A can also bond to U, so in messenger,

A ALWAYS BONDS TO U

C ALWAYS BONDS TO G

But this is rather advanced and will probably not be asked in a GCSE exam.  So the one strand copies the opposite of one strand.

When the messenger has arrived at the cytoplasm, it has the information.  The information is taken in chunks of three.  say that  T A C are next to eachother - lets say that they fit a shape triangle.  The triangle may make a certain Amino acid.  the G C T being the next set of three might make a square, accounting for another.  The three collection are called ribosomes and triplet codons.