Non-coding strand

DNA is composed of two strands of nucleotides that are bound together through several types of chemical interactions. RNA polymerase reads one of these strands, the template or coding strand, and produces an mRNA transcript, which is later translated into a protein. The DNA strand that is "read" by the polymerase is the Non-coding or template strand(coding DNA strand will have the same nucleotide sequence as the mRNA transcript read from the template strand but with uracil instead of thiamine). The coding strand always grows and is always read in the 5' to3' direction. Seemingly useless coding DNA strand is just one of the mechanisms live organisms created to decrease the chances of a random mutation of extremely valuable DNA strand. The addition of a second strand of DNA decreases the chance of nucleotides shifting along the strand, but unfortunately when a non-coding DNA strand is present a "point mutation" can occur. Point mutation is a situation in which a connected pair of nucleotides (A and T or C and G) will flip and nucleotides will take each other's places on the opposite strand.