Biomolecules — Part 1: Carbohydrates, amino acids and proteins: visual lesson, ISC Class 11 Biology

Lesson

Carbohydrates, amino acids and proteins

Part 1: the sugars that fuel and build cells, and the amino acids that are joined into proteins.

In this lesson you will

Classify carbohydrates into mono-, di- and polysaccharides and state one function of each given sugar
Draw glycine, alanine and serine, explain the zwitterion and classify amino acids
Describe the four levels of protein structure, the bonds that stabilise each and the functions of proteins

Concept

Carbohydrates are classified by the number of sugar units joined together.

Table of the three classes of carbohydrates
Class	Examples	Role
Monosaccharides	Glucose, ribose, deoxyribose	Glucose is the main fuel; ribose and deoxyribose form part of RNA and DNA
Disaccharides	Maltose, lactose, sucrose	Dietary sugars; broken down to monosaccharides
Polysaccharides	Glycogen, starch, cellulose, inulin, chitin	Stores of energy and structural materials

Diagram

Two monosaccharides join by a glycosidic bond, and one molecule of water is lost.