Cholesterol
Cholesterol is the most common steroid and is mainly synthesized in the liver; it is the precursor to vitamin D. Cholesterol is also a precursor to many important steroid hormones…
Structure of Steroid Molecules
Unlike phospholipids and fats, steroids have a fused ring structure. Although they do not resemble the other lipids, they are grouped with them because they are also hydrophobic and insoluble…
Defining Characteristics of Phospholipids
Phospholipids are major components of the plasma membrane, the outermost layer of animal cells. Like fats, they are composed of fatty acid chains attached to a glycerol backbone. Unlike triglycerides,…
Glycerol and Fatty Acids
A fat molecule consists of two main components: glycerol and fatty acids. Glycerol is an alcohol with three carbons, five hydrogens, and three hydroxyl (OH) groups. Fatty acids have a…
Protein Structure
The four levels of protein structure Protein structure can be discussed at four distinct levels. A protein’s primary structure is two-dimensional - simply the sequence of amino acids in the peptide chain.…
Peptide Synthesis
In order to synthesize a peptide from its component amino acids, two obstacles must be overcome. The first of these is statistical in nature, and is illustrated by considering the…
Properties of Lipids
What are Lipids? These organic compounds are nonpolar molecules, which are soluble only in nonpolar solvents and insoluble in water because water is polar molecules. In the human body, these…
Amino Acid Analysis of Peptides
Ion-exchange chromatography When a protein is to be analysed, it is first heated with acid to hydrolyse all the peptide bonds. When such a mixture of amino acids is to…
Introduction to Amino Acids
Amino acids form polymers through a nucleophilic attack by the amino group of an amino acid at the electrophilic carbonyl carbon of the carboxyl group of another amino acid. The…
Types of Lipids
Within these two major classes of lipids, there are several specific types of lipids important to live, including fatty acids, triglycerides, glycerophospholipids, sphingolipids, and steroids. These are broadly classified as simple…
