1. An Introduction to Carbohydrates
Chapter 5
An Introduction to Carbohydrates

2. Key Concepts
Sugars and other carbohydrates are highly variable in structure.
Monosaccharides are monomers that polymerize via condensation reactions to form polymers called polysaccharides. The monosaccharides in polysaccharides are joined by different types of glycosidic linkages.
Carbohydrates have diverse functions in cells. In addition to serving as new material synthesizing other molecules, they provide fibrous structural materials, indicate cell identity, and store chemical energy.

3. Carbohydrate Structure
Location of the carbonyl
Carbon and oxygen double bonded
Number of carbons
triose - 3; pentose - 5; hexose - 6
Spatial orientation of hydroxyl groups
Carbon bonded with an -OH

4. Formation of Carbohydrates
Monomer of a carbohydrate (polysaccharide)
Sugar (ex. glucose, fructose)
Monosaccharide
Condensation Reaction
linkage of two monomers to form a covalent bond with the release of water
combination of two hydroxyl groups
forms a glycosidic linkage

5. Types of Carbohydrates in Cells
Starch - Energy storage in plants
Glycogen - Energy storage in animal cells
Chitin - Used for structural support in the cell walls of fungi and the external skeletons of insects and crustaceans.
Peptidoglycan - Used for structural support in bacterial cell walls

6. Functions in Cells, cont’d
Structural (see previous slide)
Cell identity - glycoproteins distinguish your body cells with foreign cells
Store chemical energy - photosynthesis converts sun energy into chemical energy in the form of glucose