Ch. 3.1 - Carbohydrates

hydrated carbon - CH2O

• contain hydroxyl groups (OH) and carbonyl groups (C=O) - tend to be hydrophilic due to many CH groups

monosaccharides, disaccharides, polysaccharides

• straight chain or ring, where C1 is joined to C5 • most common as glucose • usually end in “ose” • isomers play important roles in sugar - glucose and fructose are structural isomers

if C=O is at the end of the molecules it’s aldose, if not it’s ketose

3C triose, 5C pentose, 6C hexose, 7C septose

-2 monosaccharides joined together by dehydration synthesis >glucose+glucose-water=maltose >glucose+fructose-water=sucrose >glucose+galactose-water=lactose

-very long chains of monosaccharides linked together via dehydration synthesis >starch >cellulose >glycogen >chitin

• simplest of polysaccharide used as an energy storage molecule in plants • consists entirely of glucose molecules “stuck” together via dehydration synthesis • chains could be straight (amylose) or branched (amylopectin) • we have enzymes to break starches into glucose for use by our bodies (common sources: potatoes, rice, wheat, corn)

• storage polysaccharide of animals • highly branched • most often found in muscle and liver cells

• modified polysaccharide that contains nitrogen - important structural material in the exoskeletons of insects, crabs, and lobsters

• principal component of plant cell walls • most abundant organic molecule on earth • different linkages that cannot be broken down by most animals • source of insoluble fibre • cows and termites have microfibre in their guts that have cellulose and can break down cellulose