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In chemistry, an amphiphile (from Greek αμφις (amphis) 'both' and φιλíα 'love, friendship'), or amphipath, is a chemical compound possessing both hydrophilic (water-loving, polar) and lipophilic (fat-loving, nonpolar) properties. [1] Such a compound is called amphiphilic or amphipathic.
[1] [2] The word hydrophobic literally means "water-fearing", and it describes the segregation of water and nonpolar substances, which maximizes the entropy of water and minimizes the area of contact between water and nonpolar molecules. In terms of thermodynamics, the hydrophobic effect is the free energy change of water surrounding a solute. [3]
The water molecule is amphoteric in aqueous solution. It can either gain a proton to form a hydronium ion H 3 O +, or else lose a proton to form a hydroxide ion OH −. [7] Another possibility is the molecular autoionization reaction between two water molecules, in which one water molecule acts as an acid and another as a base. H 2 O + H 2 O ...
In the case of most saponins, one of these substituents is a sugar, so the compound is a glycoside of the base molecule. [1] More specifically, the lipophilic base structure of a saponin can be a triterpene, a steroid (such as spirostanol or furostanol) or a steroidal alkaloid (in which nitrogen atoms replace one or more carbon atoms ...
In one simplified version, the saponification of stearin gives sodium stearate. C 3 H 5 (O 2 C(CH 2) 16 CH 3) 3 + 3 NaOH → C 3 H 5 (OH) 3 + 3 NaO 2 C(CH 2) 16 CH 3. This process is the main industrial method for producing glycerol (C 3 H 5 (OH) 3). Some soap-makers leave the glycerol in the soap. Others precipitate the soap by salting it out ...
Hydrophobic collapse is a proposed process for the production of the 3-D conformation adopted by polypeptides and other molecules in polar solvents. The theory states that the nascent polypeptide forms initial secondary structure (ɑ-helices and β-strands) creating localized regions of predominantly hydrophobic residues.
A handmade soap bar Two equivalent images of the chemical structure of sodium stearate, a typical ingredient found in bar soaps Emulsifying action of soap on oil. Soap is a salt of a fatty acid (sometimes other carboxylic acids) used for cleaning and lubricating products as well as other applications. [1]
Hydrophobins are known for their ability to form a hydrophobic (water-repellent) coating on the surface of an object. [2] They were first discovered and separated in Schizophyllum commune in 1991. [3] Based on differences in hydropathy patterns and biophysical properties, they can be divided into two categories: class I and class II ...