Chapter 3.2: Carbohydrates Are Made from Simple Sugars

Flashcards from Chapter 3.2 of Principles of Life, 3rd Edition.

Carbohydrates

A group of molecules varying in size, properties, and functions, with the chemical formula C_m(H₂O)_n and a hydroxyl group connected to C atoms

• Those with less than 12 carbons are simple sugars

• Can be small or joined together

Monosaccharides

The simplest carbohydrates, with a linear or ring formation formed by 5 or 6 carbons

• Comprised of structural or stereoisomers, differing in arrangement for binding

• Polymer structures depend on these

Disaccharides

Two monosaccharides joined in a condensation reaction

• Linked by a glycosidic bond formed by two hydroxyl groups that form water and oxygen

• Like monosaccharides, these can be broken down for energy or bonded to other macromolecules

Oligosaccharides

Three to ten monosaccharides, modified by their functional groups

• Often covalently bonded to proteins or lipids for functions or solubility, and can be found on the outsides of cells as signals

Polysaccharides

Hundreds to thousands of monosaccharides, joined by glycosidic bonds and arranged in chains or branches

• Branching depends on function and location, often for energy storage

• Hydrogen bonds can form in parallel groups, creating strength (as in cellulose)

• Joined via 1,4 glycosidic bonds for linear forms or 1,6 glycosidic bonds for branching forms (number denotes carbon order)

Starch

The principal energy storage compounds for plants

Glycogen

The principal energy storage compounds for animals, fungi and bacteria

• These are insoluble, but can have glucose ends hydrolyzed and broken down

• Grouping of these prevent osmotic pressure from building up