ABSTRACT
The long DNA helix resembles a twisted ladder made up of four types of building blocks called nucleotides: adenine, guanine, cytosine, and thymine. The nucleotides of the DNA ladder can also become isomers-slightly changing shapes. The individual base pairs of DNA are held together by hydrogen bonds, a connection where an electrically positive hydrogen ion attracts a negative partner. The polymerase enzyme can transform small amounts of DNA into useful quantities by copying and re-copying the sequences of interest. Anyone who lacks the enzyme lactase cannot make use of lactose—and thus becomes lactose intolerant. Amylase is an enzyme that breaks down starch and that starts to work already in the oral cavity when we eat vegetables and fruits. Enzymes being the chemical workhorses in all cells are at the core of what is specific for life; the ability to drive useful reactions far from equilibrium.
