ABSTRACT
Proteins are large macromolecules that have long chains of amino acids residues known as polypeptides. A broad range of functions performed by proteins includes catalysis of metabolic reactions, response to stimuli, DNA replication, and transport of molecules from one place to another. This chapter discusses different aspects of proteins along with their novel applications. Starting with the historical background, structure of protein, their types, synthesis, and cellular functions are briefly discussed. Nutritional importance of protein is also emphasized. The chapter deals in detail with novel protein applications in the form of carrier proteins, green fluorescent protein green fluorescent protein, custom-tailored fusion proteins, functional ingredients, protein biochips, and protein nanoparticles. Significant outcomes and results are also highlighted in this regard. By the chemical composition of proteins, they are categorized into principal classes: first class is simple proteins. These are made up of single amino acids, and the second class is conjugate proteins.
