What is glycogen? How is it different from starch?

Glycogen is a carbohydrate (polysaccharide). In animals, carbohydrates are stored as glycogen. When the body needs glucose, enzymes present in the body break glycogen down to glucose. Starch is a carbohydrate consisting of two components - amylose ( 15 - 20 % ) and amylopectin ( 80 - 85 % ) whereas glycogen consists of only one component whose structure is similar to amylopectin. Glycogen is more branched Amylopectin.

What are amino acids? Give two examples.

Amino acids are organic compounds containing amine and carboxyl functional groups, along with a side chain specific to each amino acid. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen, although other elements are found in the side chains of certain amino acids. About 500 naturally occurring amino acids are known and can be classified in many ways. They can be classified according to the core structural functional groups' locations as alpha-, beta-, gamma- or delta- amino acids; other categories relate to polarity, pH level, and side chain group type. In the form of proteins, amino acid residues form the second-largest component of human muscles and other tissues. Two examples of amino acids are Glycine and Valine.