<unk> s are a class of chemical compounds and functional groups.<unk> s consist of an inorganic or organic acid in which at least one -OH (hydroxy) group is replaced by an -O-alkyl (alkoxy) group. The most common type of<unk> s are carboxylic acid<unk> s (R1-C(=O)-O-R2), other<unk> s include phosphoric acid, sulfuric acid, nitric acid, and boric acid<unk> s. Volatile<unk> s often have a smell and are found in perfumes, essential oils, and pheromones and give many fruits their scent. Ethyl acetate and methyl acetate are important solvents, fatty acid<unk> s form fat and lipids, and polyesters are important plastics. Cyclic<unk> s are called lactones. The name<unk> " is derived from the German Essig-Äther (literally:vinegar ether), an old name for ethyl acetate.<unk> s can be synthesized in a condensation reaction between an acid and an alcohol in a reaction known as<unk> ification.
An<unk>  is an often fragrant organic or partially organic compound formed by the reaction between an acid (including amino acids) and an alcohol (alkyl, R) or aromatic alcohol (aryl, R') (including a more basic amino acid) with the elimination of water. For examples,
acetic acid + an alcohol <=> acetic<unk>  + water,
CH3COOH + ROH <=> CH3COOR + H2O,
or
CH3COO- + H+ + R+ + OH- <=> CH3COOR + H2O;
with one amino acid acting as a base:
formic acid + L-methionine <=> N-formyl-L-methionine (an amino acid) + H2O,
or
two amino acids:
Cys + Gly <=> Cys-Gly + H2O,
forming a dipeptide. A reaction between an inorganic hydroxide (e.g. sodium hydroxide) and an organic acid (e.g. acetic acid) produces a salt of acetic acid (sodium acetate). A compound is an<unk>  when the hydroxide donor is organic and a salt when the hydroxide donor is inorganic. Hence, a carbonate can be thought of as a salt or an<unk>  of carbonic acid.
Ester
Ramogen
Thiometon
Testicular artery
FODMAP
Endometrium
Testolactone
G-LOC