Organic and biochemistry Assistance Lecturer Amjad Ahmed Jumaa Elimination reactions. Bimolecular elimination (E2). Unimolecular elimination (E1); Biochemistry Organic chemistry of biomolecules. Lipids; occurrence and composition of fats. Fats as sources of pure acids and alcohols. 1

The organic chemistry of biomolecules: The study of biology at the molecular level is called biochemistry. It is a branch of biology, but it is equally a branch of organic chemistry. The biomolecules are bigger and more complicated than the ones we have so far studied. The physical and chemical properties of these compounds depend on molecular s tructure Fats (lipids): Fats and oils are naturally occurring mixtures of triacylglycerols, also called triglycerides. They are differing in that fats are solids at room temperature and oils are liquids.

Occurrence and composition of fats: The lipids, as substances, in soluble in water, that can be extracted from cells by organic solvent of low polarity like ether and chloroform. The lipids include compounds of many different kinds: steroids, and terpenes. We see chemically, fats are carboxylic esters derived from the single alcohol, glycerol:

The fatty acids may be saturated or unsaturated depends upon the presences of the double bonds or not. The fatty acids are all straight-chain compounds, ranging from three to eighteen carbons

Unsaturation in fat tends to lower its melting point and thus tends to make it a liquid at room temperature, the most common of these acids are:

We can convert unsaturated fats by hydrogenation of some of the double bonds in such cheaper fats as cottonseed oil, corn oil, converts these liquid fats to solid fats, in which take place under such mild condition ( Ni catalyst, deg. ), this operation is called the hardening of oils or( drying oils). Fats as sources of pure acids and alcohols: Fats are sometimes converted by alcohol in the basic medium into the methyl esters of carboxylic acids.

A) An aldohexose: is a six-carbon monosaccharide containing an aldehyde group. For example, (+)-Glucose, has the molecular formula (C 6 H 12 O 6 ). A six-carbon, straight-chain, pentahydroxy aldehyde that is (+)-glucose is an aldohexose.