Carbohydrate Structure and Function Flashcards
monosaccharide
basic structural unit of carb
triose, tetrose, pentose, hexose
monosaccharides with 3, 4, 5, and 6 carbons
aldoses
carbs that contain aldehyde group as most oxidized functional group
ketose
carbs that contain ketone group as most oxidized functional group
anomer
differ in configuration at anomeric carbon
alpha anomer
has -OH axial and down
beta anomer
has -OH equatorial and up
mutarotation
spontaneous cycling between alpha and beta anomers when exposed to water or acid/base
aldonic acids
straight chain aldoses that have been oxidized
reducing sugar
any monosaccharide with a hemiacetal ring
lactone
cyclic aldose that has been oxidized
Tollen’s reagent
(Ag(NH3)2)+; reduced to produce a silvery mirror when aldehydes are present
Benedict’s reagent
Cu(OH)2; results in a red precipitate when aldehyde is present
tautomerization
rearrangement o fonds in a compound, usually by moving a hydrogen to form a double bond
enol
compound with a double bond and an alcohol group
alditol
when the aldehyde of an aldose is reduced to an alcohol
deoxy sugar
contains a hydrogen that replaces a hydroxyl group on the sugar
acetals
hemiacetals react with alcohol to form this
disaccharide
to monosaccharides linked with glycosidic bonds between their hydroxyl groups
polysaccharide
long chains of monosaccharides linked with glycosidic bonds
cellulose
main structural component of plants; chain of beta d-glucose molecules linked by beta-1,4 glycosidic bonds
starch
polysaccharides that are linked by alpha d-glucose monomers
amylose
linear glucose polymer linked by alpha-1,4 bonds
amylopectin
has alpha-1,4 bonds as well as 1,6
beta- and alpha-amylase
beta amylase cleaves amylose at the nonreducing end (end with the acetal) while alpha cleaves randomly
glycogen
similar to starch but has more 1,6 bonds; highly branched
glycogen phosphorylase
functions by cleaving glucose from the nonreducing end of a glycogen branch and phosphorylating it, producing glucose-1-phosphate
