monosaccharides and disaccharides Flashcards
two molecules that are made of the same atoms connected in the same sequence, but the atoms are positioned differently in space
stereoisomers
non-superimposable mirror images
enantiomers
D-Ribose and L-Ribose are
enantiomers
stereoisomers that are not enantiomers (not mirror images)
diastereomers
D-arabinose and D-ribose are
diastereomers
diastereomers that differ at a single chiral carbon
epimers
D-glucose and D-mannose are ____that differ at____
epimers
second carbon position
an aldehyde and an alcohol make a
hemiacetal
a ketone and an alcohol make a
hemiketal
the two possible diastereomers that are formed because of cyclization
anomers
alpha D glucose OH group is
not in the same plane as the oxygen
beta D glucose OH group is
in the same plane as the oxygen
monosaccharides may readily undergo several oxidation reactions in the presence of metal ions or certain enzymes
oxidation
D-gluconic acid is an example of
aldonic acid
D-glucuronic acid is an example of
uronic acid
D-glucaric acid is an example of
aldaric acid
can be produced if the carbonyl groups of aldonic and uronic acids react with an OH group in the same molecule
lactone
example of naturally produced lacone
L-ascorbic acid (vitamin C)
powerful reducing agent that protects cells from reactive oxygen and nitrogen species
Vitamin C
another name for sugar alcohols
alditols
sugar alcohols are produced by the _____of aldehyde and ketone groups of monosaccharides
reduction
free OH groups of carbohydrates can be converted to esters by reaction with acids
esterfication
the products of the dehydration of a carboxylic acid and an alcohol
esters
originally called dextrose, it is found in large quantities throughout the natural world, a primary fuel for living cells, preferred energy for brain cells and cells without mitochondria
D-glucose
often referred to as the fruit sugar, because of its high content in fruit, twice as sweet as sucrose, used as a sweetening agent
D- fructose
sperm use ____ as an energy source
fructose
necessary to synthesize a variety of important biomolecules
galactose
a genetic disorder resulting from a missing enzyme in galactose metabolism
galactosemia
D-glucuronic acid is used in the liver to improve water solubility to remove waste molecules
uronic acids
D-glucosamine and D-galactosamine are the most common and often attached to proteins or lipids
amino sugars
form of sugar found in DNA
deoxy sugars
two monosaccharides linked by a glycosidic bond
disaccharides
disaccharide found in milk
lactose
lactose is made of
galactose and glucose via beta 1,4 linkage
lactose is a
reducing sugar
an intermediate product of starch hydrolysis
maltose
maltose has what kind of bond
alpha 1,4 linkage between two glucose molecules
a degradation product of cellulose
cellobiose
cellobiose has what kind of bond
beta 1,4 glycosidic bond between two glucose molecules
common table sugar produced in the leaves and stems of plants
sucrose
sucrose has what kind of bond
alpha, beta 1,2 glycosidic bond between glucose and fructose
sucrose is a
nonreducing sugar
have one type of monosaccharide and are found in starch, glycogen, cellulose, and citin
homoglycans
the energy reservoir of plant cells and a significant source of carbohydrates in human diet
starch
two polysaccharides occur together in starch
amylose and amylopectin
is composed of long, unbranched chains of D-glucose with a 1,4 linkages between them
amylose
branched forms of starch
amylopectin
the branches in amylopectin occur where
alpha 1,6 linkage
a polymer of D-glucopyranosides linked by beta 1,4 glycosidic bond
cellulose
most abundant organic substance on earth
cellulose
result from carbohydrates being linked to proteins and lipids
glycoconjugates
distinguished from other glycoproteins by their high carbohydrate content, roles in organizing extracellular matrix, involved in signal transduction
proteoglycans
example of a genetic disorder involving the metabolism of proteoglycans
hurler’s syndrome
polysaccharide in which parallel strands are joined by hydrogen bonds
cellulose
chitin
used for structural support in the cell walls of fungi and the external skeletons of insects and crustaceans
contain a nitrogen group
chitin
used for structural support in bacterial cell walls and have a chain of four amino acids
peptidoglycans
