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Biological molecules. Properties of carbon Carbohydrates. What are biological organic molecules made of?. All have carbon and hydrogen May include oxygen, nitrogen, phosphorus, or sulfur Can form many shapes Many have been synthesized from pure elements. Carbon backbones (skeletons).
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Biological molecules Properties of carbon Carbohydrates
What are biological organic molecules made of? • All have carbon and hydrogen • May include oxygen, nitrogen, phosphorus, or sulfur • Can form many shapes • Many have been synthesized from pure elements
Carbon backbones (skeletons) • Hydrocarbons are made of carbon and hydrogen • Fossil fuels • Backbone of many large molecules • Contribute to molecular diversity
Functional groups • Form hydrogen bonds • Isomers (ketones and aldehydes) • Can ionize in water • Can interact within a molecule • Can make a positively or negatively charged part of a molecule • Affect the function of the molecule
Isomers • Structural- arrangement of covalent bonds • Geometric- cis and trans • Enantiomers (chiral, stereo) • Living systems tend to produce one or the other • The “wrong” form can be harmful
Carbohydrates: (CH2O)n • Important energy storage molecules • Huge diversity of forms • Can help distinguish individuals within a species (or even different molecules) • Monomer • Polymer
Monosaccharides (simple sugars) • Typically contain 3-7 carbons • 5- and 6-carbon sugars are especially important in living systems • Many of these sugars have isomers
Disaccharides Monosaccharides form disaccharides Maltose is found in grains, sweet potatoes, fruits Lactose is found in milk Plants form sucrose Glycosidic linkage joins the two monosaccharides
Polysaccharides may contain thousands of glycosidic linkages • Major polysaccharides include glycogen, starch, and cellulose • Polymers of glucose • Vary by sugar linkages and origin
Chitin is also a structural polysaccharide • Building block of exoskeletons of arthropods • Calcium carbonate makes it rigid • Also found in cell walls of fungi
Oligosaccharides are very common in nature • cryst.bbk.ac.uk
Purposes of oligosaccharides • Stability • Signaling • Usually linked to proteins or lipids • Can be useful in identification (e.g., blood typing)
The story so far…. • Biological molecules have a carbon backbone • Carbohydrates have the general formula (CH2O)n • Carbohydrates are important sources of energy • Carbohydrates are diverse in structure, function, and distribution