Carbohydrate Structure and Function Flashcards
Monosaccharides
basic structure of carbohydrates
3 C = triose
4 C = tetrose
5C = pentoses
6 C = hexoses
Aldoses/Ketoses
carbohydrates with aldehydes and ketones respectively
Glyceraldehyde
simple sugar aldose
Numbering Carbons of Carbs
most oxidized carbon is labeled C-1
like orgo
Glycosidic Linkages
aldehyde carbon participates in these where sugars act as substituents
Dihydroxyacetone
simplest Ketose
carbonyl carbon is most oxidized
for msot ketones, the Ketone C is C-2
D-Fructose
2 CH2OH terminals
OH position
left
right
right
6 Carbons
D- Glucose
OH position
right
left
right
right
D-Galactose
OH position
right
left
left
right
D-Manose
OH position
left
left
right
right
Sterioisomers
optical isomers
have same chemical formula but differ in spatial arrangement
Enantiomers
non identical, non superimposable and non symmetry
mirror images (flip)
contain chiral carbons
same sugar different optical families
D and L carbs are _____ of each other
mirror images
Number of Stereoisomers With Common Backbone
=2^n
n = number of chiral carbons
Dvs L
D is positive roation
L is negative rotation
all detemined experimentally
All D-Sugars have the hydroxide of highest numbered chiral center on the _____ and all L sugars have the hydroxide on the ____. Every chiral center in D has the _____ of the L.
right
left
opposite
Diastereomers
two sugars that are in same family (aldose or ketonse) that are not identical or mirror images
Epimers
subtype of diasteriomers that differ only at one chiral center
Because monosacharides contain both a nucelophilic hydroxyl and electrophilic carboxyl, they can form cyclic ____ and _____.
Only six membered ____ or five membered _____ rings can do it due to ring strain.
The carbonyl carbon becomes ____ and is refered as the ____ carbon.
hemiacetals
hemiketals
furanose
pyranose
chiral
anomeric
Anomers
the anomeric carbon when acetal formation occurs can be either B or alpha
alpha - OH of C1 is trans and CH2OH is axial down
beta - OH of C1 is cis and CH2OH is equatorial up
When converting monosaccharide from fisher to Haworth, anything on the _____ of the fisher will be facing down
right
Exposing hemiacteal rings to water will cause them to spontaneously cycle between….this is known as _____ as it can change from alpha and beta anomer.
Happens more rapidly with presence of ____
closed and unclosed
mutarotation
acid
In solution, the ______ configuration is less favored because the hydroxyl group of the anomeric carbon is axial causing strain
axial
Monosaccharides contain _____ and ______ and do reactions like ____ and _____, ____ and )))))) .
alchols
aldehydes/ketones
oxidation and reduction
esteridication
nucelophilic attack
Oxidized aldoes occur when hemiacetal rings spend time in _______ form and have the aldehyde oxidized to a _____. They are called ____
Becauses aldoses can be oxidized, they are regarded as _____
open chain aldehyde
carboxylic acid
aldonic acids
reducing agents
Any sugar with a hemiacetal ring is considered a _______
reducing sugar
Lactone
alsose in ring form that is oidized
a cyclic ester with a carbonyl group on the anomeric carbon
Tollens Reagent
uses Ag(NH3)2+ as oxidizing agent to detet reducing sugars
Ag+ goes to metallic sugar
Benedicts Reagent
aldehyde of aldose is oxidized dictated by precipitate of Cu2O red
Although Ketones cannot be oxidized to carboxylic acids, they can _____ to form ______ in basic conditions to test positive on Tollen and Benedict tests. They are therefore _______
tautemerize
aldolases
reducing sugars
Tautomerization
rearrangement of bonds by moving hydrogen and forming a double bond
for ketones, the group picks up a Hydrogen, carbons between adjacent carbons and an enol is formed
Alditol
aldehyde of an aldose is reduced to an alcohol
Deoxysugar
contains a H that replaces a hydroxyl group on the sugar
D-2-deoxyribose in DNA
Because carbohydrates have ______ they can react with carboxylic acids/derivatives to form _____
This can be seen in phosphrylation of glucose where a _______ is formed
hydroxyl groups
esters
phosphate ester
thing glucose phosphoryltaion
Heiacetls react with alcohols to form _____. The anomeric hydroxyl group is turned into an _______. THe c-o bonds are called ____ and the acetals are called ______.
THis formation is a ____ reaction requiring _____.
acetals
alkoxy
glycosidic bonds
glycosides
dehydration
hydrolysis
Disaccharides and polysaccharides form as a result of _____ between monosacahrides
glycosidic bonds
Complex Carbohydrates
carbohydrates with atleast two sugar molecules linked together
Disacharides
monosacharides react with alcohols to form acetals,
glycosidic bond occurs between hydroxyl groups of two monosaccharids
2 Glucose Alpha 1-4 glcosidic Bond Molecule
Maltose
2 Glucose B 1-4 Glycosidic Linkagee
Cellobiose
Important Disacharides
Sucrose
Lactose
Maltose
Homopolysaccharide
polysaccahride made up of only one type of monosacharide
Heteropolysaccharide
polysaccharide made up of multilple types of monosacahrides
Most important polysaccharides
cellulose
starch
glycogen
Because glycosidic bonding can occur at multiple hydroxyl groups in a monosaccharide, polymer formation can be ______ or _____
linear
branched
Cellulose
main structure of plants
homopolysaccharide B D glucose with B1-4 linkages and H bonds for support
we cannot digest as we lack cellulase
Starches
alpha D glucose monomers
alpha 1-4 glycosidic linkages for amylose
alpha 1-6 glycosidic bonds amylopectin
B Amylase
cleaves amylose at the nonreducing end of the polymer to make maltose
A AMylase
cleaves randomly around amylose to making maltose and glucose
Glycogen
alpha 1-6 linkages every 10
similar to startch but for animals
highly branched
branching makes it more soluble and stored and allows for glycogen to be cleaved by glycogen phosphorylase
Glycogen Phosphorylase
cleaves glycose from nonreducing end of glycogen branch and phosphorylates it to Glucose 1 P
