Exam 2 Flashcards
most abundant biological molecules
carbohydrates
Monosaccharides
the building blocks (monomers) of carbohydrates
Polysaccharides
polymers of monosaccharides
General formula for monosaccharides
CnH2nOn
n varies from 3 to 8
Monosaccharides are classified by their
number of carbon atoms
The letters ose designate a
sugar
two classifications of monosaccharides
aldose
ketose
Aldose
a monosaccharide containing an aldehyde group
ketose
a monosaccharide containing a ketone group
carbons in an aldose are numbered using the carbonyl carbon as
carbon 1
carbons in a ketose are numbered using the carbonyl carbon as
carbon 2
Chiral carbon
a carbon that has four different groups attached to it
Chirality is used to assign monosaccharides into the
D-configuration or L-configuration
mammalian amino acids are
L-configuration
Dextrorotary
d-configuration
right or clockwise
Levorotary
L- configuration
left or counter clockwise
D-monosaccharide
a monosaccharide that has the -OH on its penultimate carbon on the right
L-monosaccharide
a monosaccharide that has the -OH on its penultimate carbon on the left
Dextrose
old name for D-glucose
D and L configurations are
enantiomers
mirror images
Diastereomers
monosaccharides that have the same number of carbons, and have a different stereoisomeric configurations but that are NOT mirror images of each other
Epimers
differ in configuration at one asymmetric chiral carbon
subset of diastereomers
Triose
sugar with 3 carbons
Tetroses
sugar with 4 carbons
pentoses
sugar with 5 carbons
hexoses
sugar with 6 carbons
aldohexose
glucose
fructose
ketohexose
galactose
aldohexose
ribose
aldopentose
The alcohol on carbon 5 can react with the aldehyde on carbon one or the ketone on carbon two to form a
hemiacetal or hemiketal respectively
ring structure of a monosaccharide
Haworth projection
In the cyclization of glucose the carbonyl carbon becomes
the anomeric carbon
the C attached to two O atoms by single bond