Ribonucleic acid (RNA) is a linear molecule composed of four types of smaller molecules called ribonucleotide bases: adenine (A), cytosine (C), guanine (G), and uracil (U).ach ribonucleotide base consists of a ribose sugar, a phosphate group, and a nitrogenous base. Adjacent ribose nucleotide bases are chemically attached to one another in a chain via chemical bonds called phosphodiester bonds. Unlike DNA, RNA is usually single-stranded.
Urushi is a kind of natural lacquer collected from the Urushi tree. We Japanese have a 6000 year history of the use of Urushi.Initially it was used as an adhesive, like fixing an arrowhead to the wooden shaft, applying gold foil or fixing chipped porcelain.hen it came to be used for finishing lacquer soup bowls and furniture. The Urushi tree grows in many parts of east Asia including Japan. Collecting Urushi is like collecting gum from rubber tree. We cut the bark of the tree and then the tree yeilds a milky-white sap to cure the wound.
When we hear of urushi lacquerware, we think of shiny objects such as boxes and bowls covered with gold or colored maki-e decorations. However, the idea of decorating on top of urushi is a relatively new idea. Until the 18th century, urushi lacquer ware was quite plain with no decoration.Red or black urushi was used on a wide variety of objects from household necessities such as rice bowls, sake cups and combs to hunting tools.hile most paints dry by the evaporation of some solvent, urushi dries or hardens by absorbing moisture from the air. The urushi sap contains an oily substance called urushiol. When exposed to warmth and humidity, an enzyme is activated and extracts oxygen from the water and supplies it to the urushiol.