Carbohydrates Flashcards
what is the empirical formula?
(CH2O)n
what are some of the functions?
storage form of energy
component of cell membrane
structural components of many organisms
dietary requirements
what is the classification of a carbohydrate with one saccharide?
monosaccharide
what is the classification of a carbohydrate with two saccharide?
disaccharide
what is the classification of a carbohydrate with three to ten saccharide?
oligosaccharides
what is the classification of a carbohydrate with more than ten saccharide?
polysaccharide
what is the name of a monosaccharide that has 3 carbon atoms?
trioses
what is the name of a monosaccharide that has 4 carbon atoms?
tetroses
what is the name of a monosaccharide that has 5 carbon atoms?
pentoses
what is the name of a monosaccharide that has 6 carbon atoms?
hexoses
monosaccharides can have structural isomers that have what in their structure?
ketone (C=O in structure) or aldehydes (C=O on ends of structure)
which end are the carbons numbered from?
beginning at the end which has the carbonyl carbon (aldehyde or keto group)
what are isomers?
Compounds that have the same chemical formula but have different structures
what are epimers?
Carbohydrate isomers that differ in configuration around only one specific carbon atom
what are enantiomers?
mirror images
designated D- and L- sugars
the majority of the sugars in humans are D- sugars
what is the structure of 99% of monosaccharides?
in a cyclisation of monosaccharides/ ring formations
what is the classification of a monosaccharide if the OH group faces down
alpha
what is the classification of a monosaccharide if the OH group faces up?
beta
what are the bonds that link sugars together?
glycosidic bond (catalysed by glycosyltransferases)
how do you name a glycosidic bond?
If this anomeric hydroxyl is in the configuration, the linkage is an α-bond. If it is in the configuration, the linkage is a beta-bond
when can the cyclisation of monosaccharides open the ring?
if the hydroxyl group on the anomeric carbon is not linked to another compound
the sugar can then act as a reducing agent and is given the term reducing sugar
why is glucose important?
main sugar in the body
important source of energy
glucose is stored in large polymers which are osmotically inactive
ribose in nucleotide and nucleic acids
present in plasma membrane
form glycoproteins, glycolipids and lipids
what is the structure of glycogen?
alpha 1,6 glycosidic bonds
alpha 1,4 glycosidic bonds
similar to amylopectin in starch but more branched
what are the two forms of starch?
amylose and amylopectin
