Carbs & Glucose Flashcards
what are carbohydrates?
Polyhydroxylated aldehydes or ketones with three or more carbon atoms, or substances which can be hydrolysed to form these.
monosaccharides
Defined functionally as carbohydrates which cannot be hydrolysed (broken down) further into simpler compounds.
two broad types of monosaccharides:
Aldoses
Ketoses
Aldoses
contain an aldehyde group (i.e. terminal CHO)
Ketoses
contains a keto group (i.e. an internal C=O)
monosaccharide structure
Can be chemically identical but have a 3D arrangement of atoms.
Enantiomers
Mirror image forms
Have identical chemical and physical properties
Each shares the same molecular formula but has a different structure.
Two forms cannot be superimposed on one another.
Chiral carbon
C5 = reference carbon
in solutions glucose can …
form ring structures
Aldehyde groups can react with hydroxyl groups, form something called a hemiacetal.
glucose ‘eats its tail’ to form ….
an intramolecular hemiacetal
x-orientation
OH group on the anomeric carbon is cis to the CH2OH
ss-orientation
OH group on the anomeric carbon is trans to the CH2OH
Fates of Glucose
> breakdown via glycolysis.
Modify other molecules.
Storage: Glycogen, starch.
Glycolysis
splitting of sugar
universal pathway for glucose breakdown
some cells very dependent on it ( brain, RBC, sperm)
