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• The test has been postponed until Wednesday.
• The reading packets are due on Wednesday.
You Must Know
• The cellular functions of carbohydrates.
• How the sequence and subcomponents of carbohydrates determine their properties.
• How changes in organic molecules would affect their function.
Concept 3.3: Carbohydrates serve as fuel and building material
• Carbohydrates include sugars and the polymers of sugars
• Monosaccharides – serve as a major fuel for cells and as raw material
for building molecules.
– have molecular formulas that are usually multiples of CH2O
– classified by the number of carbons in the carbon skeleton and the placement of the carbonyl group
Figure 3.7c
6-carbon sugars (C6H12O6)
Glucose Fructose
Carbonyl
Aldehyde – because the carbonyl group is at the end of the carbon skeleton.
Ketone – because the carbonyl group is within the carbon skeleton.
Figure 3.9-2
Glucose Fructose
Sucrose
glycosidic linkage
Polysaccharides
• Polysaccharides, the polymers of sugars, have storage and structural roles
• The structure and function of a polysaccharide are determined by its sugar monomers and the positions of glycosidic linkages.
© 2014 Pearson Education, Inc.
Storage Polysaccharides
• Starch, a storage polysaccharide of plants, consists entirely of glucose monomers
• Plants store surplus starch as granules• The simplest form of starch is amylose
© 2014 Pearson Education, Inc.
Starch granulesin a potato tuber cell Starch (amylose)
Glucosemonomer
• Glycogen is a storage polysaccharide in animals• Humans and other vertebrates store glycogen
mainly in liver and muscle cells
© 2014 Pearson Education, Inc.
Glycogen granulesin muscletissue
Figure 3.11(a) and glucose
ring structures
Glucose Glucose
(b) Starch: 1–4 linkage of glucose monomers
Hydroxyl Hydroxyl
(c) Cellulose: 1–4 linkage of glucose monomers
Figure 3.10c
Cellulose microfibrilsin a plant cell wall
Cellulosemolecules
Hydrogen bondsbetween —OH groups oncarbons 3 and 6
© 2014 Pearson Education, Inc.
Chitin
