INTRO TO CARBOHYDRATES Flashcards
most abundant organic molecules in nature -
erve as a structural component of many organisms
Carbohydrates
Simple sugar
Monosaccharides
2 monosaccharide units
Disaccharides
3-10 monosaccharide units
Oligosaccharides
more than 10 sugar units
Polysaccharides
Compounds having same chemical formula but different structural formula
Isomerism
are isomers that differ in configuration around only one specific carbon atom.
Glucose a
Epimers
Structures that are mirror images of each other and are designated as D- and L sugars based on the position of –OH grp on the asymmetric carbon farthest from the carbonyl carbon.
Enantiomers (D- and L-Forms)
In solution, the cyclic α and β anomers of a sugar are in equilibrium with each other, and can be interconverted spontaneously
Mutarotation
can detect a reducing sugar in urine. A positive result is indicative of an underlying pathology, because sugars are not normally present in urine, and can be followed up by more specific tests to identify the reducing sugar
colorimetric test
joining of 2 monosaccharides by O-glycosidic bond
Dissaccharides
are attached to non-carbohydrate structures by glycosidic bonds (O- or N-type).
Complex Carbohydrates
Glycosidic Bonds
N-Glycosidic
O-Glycosidic
are large complexes of negatively charged heteropolysaccharide chains.
Glycosaminoglycans (GAGs)
Most abundant GAG
Chondroitin sulfates:
Most heterogeneous GAGs
Keratan sulfates
Compared to other GAGs, it is unsulfated and not covalently attached to protein.
Hyaluronic acid
intracellular and serves as an anticoagulant
Heparin
principal sites for digestion
mouth and intestinal lumen
is catalyzed by glycoside hydrolases (glycosidases) that hydrolyze glycosidic bonds.
Digestion
acts briefly on dietary starch and glycogen, hydrolyzing random α(1→4) bonds.
Salivary a-amylase
continues the process of starch digestion.
Pancreatic a-amylase
-final digestive process
Intestinal disaccharidases
