Lipase catalyzed hydrolysis of fats? Help please!
Fats, or triglycerides consist of 1 molecule of glycerol and 3 fatty acid chains with an ester bond between them. They are the main ingredient in vegetable oil and animal fats. The length of the fatty acid chains is usually 16 to 20 carbons long. Lipase helps break the bonds. Glycerol usually goes through glycolysis metabolism. Bile, made in the liver and stored in the gallbladder is released into the small intestine during digestion and it emulsifies fats (makes them into small fat droplets) that are absorbed by the lymph and carried to the bloodstream where the two combine just before going to the heart.
Acid-Catalyzed Hydrolysis -- Organic Chemistry?
For the best answers, search on this site https://shorturl.im/avIWs Without knowing the identity of the ester, it's hard to propose an appropriate workup scheme. In general, though, you'd want to do something like this: The carboxylic acid is acidic enough to be deprotonated by NaHCO3, whereas the alcohol is not. Add some NaHCO3 to the aqueous reaction mixture, then add an extraction solvent - either ether or DCM. The carboxylic acid will be deprotonated and migrate into the aqueous phase. Hopefully, the alcohol will go into the organic phase. If it does, you can wash the organic phase with brine, dry it with a drying agent, and evaporate the solvent to obtain the pure alcohol. To obtain the carboxylic acid, take the basic wash, reacidify with 1M HCl, and extract with ether or DCM. Hopefully, the protonated form of the carboxylic acid won't be soluble in the aqueous phase and will migrate into the organic phase in the presence of HCl. Wash the organic phase with brine, dry it with a drying agent, then evaporate the solvent to obtain the pure acid. Unfortunately, this procedure won't work for all esters. If the alcohol is small - less than 4 carbons - it will be soluble in water, and the NaHCO3 wash won't work; both the acid and the alcohol will migrate into the aqueous phase. And if the acid is small - less than 5 carbons - the protonated form will be soluble in water too, so reacidifying won't bring it into the organic phase. If the boiling point difference between the alcohol and the ester is sufficiently large, simple distillation would work to separate the two. If the boiling point difference is small, a fractional distillation might work. In an acid-catalyzed catalyzed hydrolysis, the carboxylic acid will be in its protonated form at the end of the reaction, so you'd need to do basify the mixture to bring the acid into the aqueous phase. In a base-catalyzed reaction, the carboxylic acid will be present as its carboxylate anion, so the basic wash would be unnecessary; just extract the reaction mixture with an organic solvent to separate out the alcohol. The remaining steps would be the same.
Acid hydrolysis of an ester, why is a dilute acid used?
THE MECHANISM FOR THE ACID CATALYZED HYDROLYSIS OF ESTERS The mechanism for the hydrolysis of ethyl ethanoate Ethyl ethanoate is heated under reflux with a dilute acid such as dilute hydrochloric acid or dilute sulphuric acid. The ester reacts with the water present to produce ethanoic acid and ethanol. Because the reaction is reversible, an equilibrium mixture is produced containing all four of the substances in the equation. In order to get as much hydrolysis as possible, a large excess of water can be used. The dilute acid provides both the acid catalyst and the water. dilute acid CH3COOCH2CH3 + H2O ===========> CH3COOH + CH3CH2OH The mechanism mechanism cannot be explained here so follow this link: http://www.chemguide.co.uk/physical/catalysis/hydrolyse.html
Can a nucleic acid be hydrolized?
Yes. RNA is susceptible to alkaline hydrolysis because of presence of free 2'-OH on ribose, as shown in this diagram. DNA is stable to alkaline hydrolysis, because it lacks the free 2'- OH on the ribose. Nucleases = enzymes that catalyze hydrolysis of the phosphodiester bonds in nucleic acids Some are specific for DNA (DNases) others specific for RNA (RNases) still others show no specificity. Exonucleases remove nucleotides from the ends, either from the 5'- or 3'- ends. Endonucleases hydrolyze internal phosphodiester bonds.