Optical Properties Quiz

Carbohydrate Overview

• Carbohydrates are characterized by their sweetness and contain an aldehyde or a ketone functional group.

Monosaccharides

• Monosaccharides are simple sugars and are the building blocks of carbohydrates.
• Examples of monosaccharides include glucose, fructose, and galactose.
• The process of converting monosaccharides to alditols is called reduction.

Disaccharides

• Disaccharides are formed by the condensation of two monosaccharides.
• A property of disaccharides is that they are sweet.

Polysaccharides

• Polysaccharides are formed by the condensation of multiple monosaccharides.
• An example of a polysaccharide is cellulose, which is a major component of wood.
• The chemical formula of polysaccharides is (CH2O)n.

Starch

• Starch is a polysaccharide found in grains and serves as a storage form of energy.

Sucrose

• Sucrose is a disaccharide composed of glucose and fructose.
• The main source of sucrose is sugarcane or sugar beets.

Stereochemistry

• Carbon atoms with four different substituents attached to them are called asymmetric carbons.
• Molecules with a single chiral center that are chiral are called optically active.
• The number of stereoisomers possible for a carbohydrate with n asymmetric carbons is 2^n.
• The Fischer projection is a method of representing the stereochemistry of a molecule.
• The D-L classification of monosaccharides is based on the stereochemistry of the molecule.

Glucose and Related Sugars

• Glucose, mannose, and galactose are all aldohexoses.
• Glucose and mannose are epimers, meaning they differ in configuration at only one asymmetric carbon.
• Glucose and galactose are epimers, meaning they differ in configuration at only one asymmetric carbon.
• Mannose and galactose are epimers, meaning they differ in configuration at only one asymmetric carbon.

Cyclic Structures

• The reaction between an aldehyde and an alcohol forms a hemiacetal.
• The cyclic structure formed by the reaction between the aldehyde on carbon 1 and the hydroxyl group on carbon 5 in glucose is called a pyranose.
• The two anomers formed by the cyclic hemiacetal formation in glucose are called α-glucose and β-glucose.
• The predominant form of glucose in a neutral aqueous solution is the β-anomer.
• The Haworth projection is a method of representing the cyclic structure of a monosaccharide.
• Cyclic sugars formed by the C1-C5 hemiacetal are called pyranoses.
• In the case of D-fructose, the reaction between the C5 hydroxyl group and the ketone carbonyl in position C2 forms a furanose.