LEARNING OBJECTIVES In this article, author has explained the functions of essential and non-essential amino acids. Essential amino acids The essential amino acids perform the following functions: Histidine is a precursor of various hormones which are essential for the function of the kidney, neurotransmission, and gastric secretion. Histidine also plays role in the immune system. …

LEARNING OBJECTIVES In this article, author has explained the introduction, structure and broad classification of amino acids. Definition The group of organic compounds which contain two functional groups; amino and carboxyl groups are called amino acids. The amino group is basic while the carboxyl group is acidic in nature. The elements that are present in…

LEARNING OBJECTIVES In this article, author has explained the introduction, structures, properties, classification and functions of proteins. Proteins are the most abundant organic molecules found in living organisms. Proteins form about 50% of the cellular dry weight. Proteins contain carbon, hydrogen, oxygen, and nitrogen. These C, H, O, and N are arranged to form amino…

LEARNING OBJECTIVES In this article, author has explained the introduction, functions and examples of amphipathic molecules. Definition The molecules which have both polar and non-polar ends are called amphipathic molecules. This characteristic gives them both hydrophobic and hydrophilic (water-loving) properties. Amphipathic molecules are lipophilic (fat-loving) For example, phospholipids have a polar phosphate head and a…

LEARNING OBJECTIVES In this article, author has explained the structure, functions and properties of steroids; cholesterol and ergosterol. The compounds which contain cyclic steroid nucleus cyclopentanoperhydrophenanthrene are called steroids. The cyclopentane ring is attached to the phenanthrene nucleus. They are various steroids of biological importance. Cholesterol, bile acids, sex hormones, vitamin D, adrenocortical hormones, sitosterols,…

LEARNING OBJECTIVES In this article, author has explained the different types of glycerophospholipids. The phospholipids which contain glycerol as alcohol is called glycerophospholipids. In glycerophospholipid, C1  and C2 are esterified with the fatty acids while C3 has a phosphate group. They are major phospholipids that occur in the cell membrane. Phosphatidic acid is involved in…

LEARNING OBJECTIVES In this article, author has explained the introduction, structure, properties, classification and functions of phopholipids. Definition The complex lipids which contain phosphoric acid in addition to fatty acids, nitrogenous bases, and alcohol are called phospholipids. Phospholipids are the main component of the cell membrane. They are naturally occurring molecules and the major component…

LEARNING OBJECTIVES In this article, author has explained introduction, occurrence, structure, physical and chemical properties, classification and functions of triacylglycerols. Definition The esters of glycerol with fatty acids are called triacylglycerols. Triacylglycerols are widely distributed in plants and animals. They are also known as neutral fats. The common name of triacylglycerols is triglycerides. Oxidation of…

LEARNING OBJECTIVES In this article, author has explained introduction, occurrence, structure, classification, and functions of fatty acids. Definition The simplest lipids with carboxylic acid and hydrocarbon side chains are called fatty acids. They are composed of carbon, hydrogen, and oxygen. Fatty acids are building blocks of fats in our body and the food we eat.…

LEARNING OBJECTIVES In this article, author has explained the introduction, structure, physical and chemical properties, classification and functions of lipids. Definition Lipids are heterogeneous compounds that are insoluble in water and soluble in organic solvents. Lipids are a major storage form of energy in the body. They naturally occur in plants, animals, and microorganisms. They…