Objectives • To understand the classification of1 carbohydrates • To become familiar with steroisomerism2 • To draw the structures of and to3 indicate the reactions of several hexoses • To compare the structures and reactions4 of disaccharides and polysaccharides
Carbohydrates• All carbohydrates are composed of carbon, hydrogen, and oxygen in a 1:2:1 empirical ratio.• The general empirical formula for a carbohydrate is CH2O. If a carbohydrate has 5 carbons atoms, what would be its empirical formula? C5H10O5 If a carbohydrate has 12 hydrogen atoms present, what would be its empirical formula? C6H12O6• Most carbohydrates end with the suffix -ose
Functions of Carbohydrates• Provide energy source: A fuel source when catabolized during cellular respiration. Energy is stored in the chemical bonds within the molecule and released during cellular respiration. Usually simple sugars.• Provide energy storage: Plants store energy in a complex carbohydrate form called starch (amylose). Animals store energy in a complex carbohydrate in their muscle tissue and liver in the called glycogen.• Structural Building Material: Plants build their cell walls of a complex carbohydrate material called cellulose. Animals such as arthropods build their exoskeletons of a complex carbohydrate called chitin. Chitin is also found in the cell walls of
Classes of Carbohydrates• There are three major classes of carbohydrates: 1. Monosaccharides (simple sugars) These are the monomers or building blocks for all other classes of carbohydrates. Examples: glucose, fructose, galactose, and ribose. 2. Disaccharides are produced by joining two simple sugars by dehydration synthesis forming a covalent bond between them. Examples: sucrose (table sugar), maltose, lactose 3. Polysaccharides (complex carbohydrates) are produced by joining many monosaccharides together by many dehydration synthesis reactions forming a polymer molecule. Examples: amylose, glycogen, cellulose, and chitin
CARBOHYDRATES THERE ARE 2 TYPES OF CARBOHYDRATES Simple Complex
Simple Sugars arecarbohydrates made up of 1or 2 monomers.They also taste sweet.
Complex Carbohydrates … What are they?Complex Cabohydrates are polymers made up of many monomers. Most also taste starchy.
Carbohydrates Carbohydrates (or saccharides) consist of only carbon, hydrogen and oxygen Carbohydrates come primarily from plants, however animals can also biosynthesize them The “Carbon Cycle” describes the processes by which carbon is recycled on our planet - Energy from the sun is stored in plants, which use photosynthesis to convert carbon dioxide and water to glucose and oxygen - In the reverse process, energy is produced when animals oxidize glucose during respiration Photosynthesis6CO2 + 6H2O + Energy C6H12O6 + 6O2 Respiration