Alison's New App is now available on iOS and Android! Download Now

Structure of Proteins

This free online course in organic chemistry and biology explains the structure and functions of proteins.

Publisher: NPTEL
In this free online course on biological chemistry, you will be introduced to the structure and functions of proteins. This course explains the hierarchical structure of proteins, the techniques that are used to determine their 3 dimensional structure, the purification of proteins and the processes used for the same and the enzymes. The course provides you with useful learning in the field of chemistry and biology.
Structure of Proteins
  • Duration

    3-4 Hours
  • Students

  • Accreditation






View course modules


In this course, you will be introduced to the structural and functional aspects of proteins. The first half of the course describes the hierarchical structure of proteins, in which you will learn about the secondary and tertiary structure of peptides and proteins. The amino acid sequence characterises the primary structure of proteins. The secondary structure is the initial folding of the sequence into alpha helices, beta sheets and beta turns. The tertiary structure is a more complex folding of the protein and the quaternary structure is the combination of two or more of the same protein. You will gain an insight into the techniques such as X-ray crystallography, NMR and electron microscopy used to determine the 3D structure of proteins. You will also learn about the Ramachandran plot which is used in the structural analysis of proteins. In order to make different geometries in protein structure, we need rotation around bonds. The course explains how to determine which bonds in the polypeptides are free to rotate and it describes the steric effect and various protein purification techniques such as ion exchange chromatography, SDS PAGE and isoelectric focusing.


Protein purification process is based on four main parameters of molecular weight, charge, solubility and affinity. This course explains the purification of proteins by proteomics and gel filtration. Proteomics means the study of all the proteins which are present together in any structure. You will also learn about protein purification using ion exchange chromatography, and 2D gel electrophoresis. In the functional aspect of proteins, the course module begins with an introduction to the different functions of proteins. One of the major functions is that they catalyze various reactions in our body. Such proteins are called enzymes. You will get a detailed explanation of enzyme catalysed reactions, types of enzymes and cofactors and the classes of enzymes. There are six classes of enzymes which are always written in a specific sequence as per the requirements of the nomenclature system for enzymes. You will learn about the Michaelis-Menten constant and maximum value of rate in the context of enzyme catalysed reactions and the factors which affect these reactions. An explanation of catalytic activity of serine protease and other types of proteases seals this concise, yet vivid course on the structure of proteins.


Proteins are associated with living organisms and at the very basic level, we have learnt about protein from the food we eat. But in biological chemistry, which is a physical science that examines the chemical processes of living systems, you not only learn the chemical structure of proteins, but it will open up new windows in the quest for further research ideas or advanced learning. In present times, chemists need to know the basics of biology to understand the nature and type of chemistry that goes on in the biological system. The biologists, too, have to study the biological system from the standpoint of molecules, that is, analyse the precise microscopic details of any process of synthesis, decomposition or break down. Hence, this course will be useful in a contemporary scientific environment. This field of study offers scope for employment, not only in the areas of academics or research and development, but in pharmaceutical sales and manufacturing, scientific regulation or analysis in any government or similar organisation. So, seek new knowledge and start learning!

Start Course Now