Unit 5 Flashcards
what atoms do carbohydrates contain
C, H and O
what is the general formula for carbohydrates
Cn(H2O)n
simplest carbohydrates are
monosacchrides
whats an example of a monosaccharide
glucose
glucose equation
C6H12O6
which carbohydrates cannot be further hydrolyzed into simpler carbohydrates
monosaccharides
which carbohydrates have 2 monosaccharides
disaccharides
which carbohydrate is sucrose an example of
disaccharide
what is C12H22O11
sucrose
all monosaccharides
glucose
fructose
galactose
all disaccharides
sucrose (glucose+fructose) lactose (glucose+galactose) maltose (glucose+glucose)
All polysaccharides
starch
glycogen
cellulose
monosaccaride formula
C6H12O6
Disaccharides formula
C12H22O11
Polysaccharide formula
-(C6H10o5)-n
glucose source
fruit
fructose source
fruits, honey
galactose source
not natural
sucrose source
sugar cane, sugar beet
lactose source
milk
maltose source
germinating grain
starch source
plants
glycogen source
animals
cellulose source
plant fiber
Fischer projection is a structure drawn with
vertical and horizontal lines
L and D are two
enantiomers
L is assigned when
OH is on the left side of the vertical line
How do you determine where to assign the L or D enantiomer
the OH group farthest away from the aldehyde or ketone
Most stable form for pentoses and hexoses are
cyclic rings, known as Haworth
what are the 2 forms termed in a haworth
anomers
which projection is in a straight line
fischer
which projection has an OH that can be drawn above or below the plane
haworth
when an OH group is drawn below the plane of the ring
alpha
OH group is above the plane of the ring
beta
Can rings reopen and close
yes
the carbon bearing the reactive carbonyl yielding two distinct configurations (α and β) are
hemiacetals and hemiketals.
what is the carbon called which is in rotation
anomeric carbon
what is it called when carbohydrates change spontaneously between a and B configurations
mutarotation
When drawn in the Haworth projection, the α configuration places the hydroxyl
downward
The spatial relationships of the atoms of the furanose and pyranose ring structures are more correctly described by the two conformations identified as the
chair form and the boat form.
is the chair form or boat form more stable
chair form
what are constitutes of the ring called that project above or below the plane of the ring
axial
what are constitutes called that project parrallel to the plane called
equilateral
In the chair conformation, the orientation of the hydroxyl group about the anomeric carbon of α-D-glucose is
axial
In the chair conformation, the orientation of the hydroxyl group about the anomeric carbon of B-D-glucose is
equilateral
monosaccharides contain what functional group
OH
most monosaccharides exist in what form
cyclic form
The most stable structure of certain forms are
rings
Oxidation of aldose monosaccharides yield
carboxylic acid
Reduction of CO group in monosaccharides yield
sugar alcohols called alditols.
Aldehyde with an adjacent hydroxyl group always respond _____ to Benedict’s test
positively
Disaccharides and polysaccharides contain both the
OH an ether or glycosidic link
what is formed When 2 monosaccharides are joined by dehydration
a disaccharide
glycosidic bonds are
Covalent bonds between the anomeric hydroxyl of a cyclic sugar and the hydroxyl of a second sugar (or another alcohol containing compound)
The linkage of two monosaccharides to form disaccharides has what bond
glycosidic bond
a disaccharide is obtained from starch, which on hydrolysis produces glucose. This on further fermentation yields ethanol. It is composed of 2 glucose monomers in an α–(1,4) glycosidic bond.
maltose
found in milk products is another disaccharide. It consists of galactose and glucose in a β–(1,4) glycosidic bond.
lactose
another disaccharide cannot form an open chain and therefore cannot be oxidized. It does not react with Benedict’s reagent and thus is not a reducing sugar. It is composed of glucose and fructose through an α–(1,2)–β-glycosidic bond
sucrose
These are polymers formed by the combination of many monosaccharides
polysaccharides
The monomeric building blocks used to generate polysaccharides can be varied; in all cases, however, the predominant monosaccharide found in polysaccharides is
D-glucose
When polysaccharides are composed of a single monosaccharide building block, they are termed
homopolysaccharides
Polysaccharides composed of more than one type of monosaccharide are termed
heteropolysaccharides
a storage form of glucose in plants is composed of 2 polysaccharides- amylose and amylopectin
starch
what happens to starches in the presence of acid
they hydrolyze easily and give dextrinwhich on further hydrolysis yields maltose and finally glucose.
animal starch is a polymer of glucose
glycogen
gives the rigid structure to cell walls in wood and fiber and more resistant to hydrolysis than starch form
cellulose
They are coiled in a helical form and consists of 250 to 4000 alpha-D glucose connected by 1-4 glucosidic bonds
startch
they are joined by alpha 1-4 glycosidic bonds and branches occurring every 10 to 15 glucose units are attached by alpha 1-6 glycosidic bonds.
glucose
what is made up of glucose form a long unbranched chain similar to that of amylose, but units are linked by beta 1-4 glycosidic bonds. The chains are aligned in parallel rows held by H bonds between OH groups in adjacent chains.
cellulose
starch monomer
glusoce
glycogen monomer
glucose
cellulose monomer
glucose
starch structure
2 components:
(a) amylopectin: 3000 - 6000 glucose units (branched, open structure)
(b) amylose: 60 - 300 glucose units (unbranched linear structure)
glycogen structure
more branched than amylopectin with an open structure
cellulose structure
Relatively unbranched linear polymer of ~3000 glucose units.
Chains linked by hydrogen bonds.
starch solubility in water
insoluble in cold water
soluble in hot water
(forms a colloid)
glycogen solubility in water
soluble in cold water
forms a colloid
cellulose solubility in water
insoluble
starch is found in
plants
glycogen is found in
animals
cellulose is found in
plants
the reduction of monosaccarides produces
sugar alchohols
the oxidation of monosaccarrides produces
sugar acids
A glycosidic bond between two monosaccharides can also be classified as a(n)
ether bond
In a disaccharide, two monosaccharides are joined by what kind of bond?
glycosidic
Which of the following contains α-1,6-branches?
glycogen
Cellulose is not digestible by humans because it contains glucose units linked by ________-glycosidic bonds
β-(1,4)
which contains β-(1,4) branches?
cellulose
Amylose is a polysaccharide which has
only α-1,4-links bonds glucose units
Humans cannot digest cellulose because they
lack the necessary enzymes to digest β-glycosides
Under acid hydrolysis conditions, starch is converted to
glucose
Amylopectin is a polysaccharide which has
both α-1,4-and α-1,6-bonds between glucose units
Glycogen is a polysaccharide which has
both α-1,4-and α-1,6-bonds between glucose units
List the three major disaccharides and examples.
maltose, lactose, sucrose
What is the basic source of energy for all living things?
glucose
Name the type of glycosidic bond in maltose
α-1,4
Name the monosaccharides used to make sucrose.
glucose and fructose
Name the three major polysaccharides and their source.
starch (plants), glycogen (animals), cellulose (wood, outer wall of plants)
Which monosaccharide makes up the 3 polysaccharides?
glucose
What is a reducing sugar? Give an example.
Carbohydrate which can reduce any substance. Glucose
What is the name of the bond formed between two monosaccharides to make a disaccharide?
glycosidic bond
table sugar
sucrose
fruit sugar
fructose
blood sugar
glucose
malt sugar
maltose
milk sugar
lactose
Determine the enantiomeric form.
D/L
Right/Left
Determine the anomeric form.
a/b
Below/above
