Risk which is common to an entire class of assets or liabilities. The value of investments may decline over a given time period simply because of economic changes or other events that impact large portions of the market.
Properties of the alpha-helix. 1  The structure repeats itself every 5.4 Angstroms along the helix axis, ie we say that the alpha-helix has a pitch of 5.4 Angstroms. Alpha-helices have 3.6 amino acid residues per turn, ie a helix 36 amino acids long would form 10 turns.
The double helix is a description of the molecular shape of a double-stranded DNA molecule. In 1953, Francis Crick and James Watson first described the molecular structure of DNA, which they called a double helix, in the journal Nature. For this breakthrough discovery, Watson, Crick, and their colleague Maurice Wilkins won a Nobel Prize in Physiology, or Medicine, in 1962.