B4 – analyse the structure and function of biological molecules in living systems - carbohydratesKnow formulas, chemical structureList functionsDifferentiate between monosaccharaides,

disaccharides and polysaccharidesCompare structure of cellulose, starch and

glycogenExplain dehydration synthesis and

hydrolysis

Carbohydrates contain C, H, and O in a ratio of approximately 1:2:1

2:1 ratio of H to O is the same is in H2O Contain repetitions of H-C-OH

Monosaccharides (Simple carbohydrates, or sugars)

Common monosaccharides have 5 or 6 carbons, usually arranged in a ring

Hexoses are 6-carbon monosaccharides Ex. Glucose, fructose, and galactose

All have the formula C6H12O6

Differ in arrangement of atoms

Structural formula for glucose:

Each corner is a carbon atom

Pentoses are 5-Carbon monosaccharides Ex. Ribose

Monosaccharides combine in chains to form polymers

Two monosaccharides combined = a disaccharide

Several monosaccharides combined = a polysaccharide

Disaccharides (2 monosaccharides) Ex. glucose + glucose maltose

Glucose + fructose sucrose

Glucose + galactose lactose

Tastes like sugar, looks like sugar, but it’s not!

Polysaccharides (complex carbohydrates)

Long, branched or unbranched chains of monosaccharides (up to 4000!)

Common examples: starch, glycogen, cellulose

Differ in orientation of bonds and degree of branching

Starch

Glycogen

Cellulose

Glucose and other monosaccharides are used in cellular respiration, to provide energy for cellular functions in all living organisms

Glycogen is used for energy storage in animals (found mainly in muscles and liver)

Starch is used for energy storage in plants (digested by animals to provide energy from food)

Cellulose provides structure in plant cell walls

Monosaccharides combine to form polymers by the process of condensation synthesis, or dehydration synthesis

A water molecule is given off for each bond that forms

Polysaccharides are broken down into monosaccharides by the process of hydrolysis

One molecule of H2O is added for each bond that is broken