PRELIM LEC: CARBOHYDRATES Flashcards
are organic compounds composed of carbon, hydrogen and oxygen
Carbohydrates
Chemical composition of carbohydrates:
Cn(H2O)n
Two forms of CHO:
Aldose
Ketose
are the major constituents of physiologic
system: brain, erythrocyte, and retinal cells in humans.They are also the major source of energy.
Carbohydrates
carbonyl group in the middle linked to 2 other carbon atoms
Ketose
terminal end carbonyl group called aldehyde group
Aldose
most important carbohydrates
glucose
is directly used as energy source and or stored as glycogen in the liver or muscles.
glucose
3 carbon:
triose sugar
5 carbon:
pentose sugar
6 carbon:
hexos sugar
Classification of CHO based on Location of carbonyl group:
aldose
ketose
classificatios of carbohydrates:
- Location of carbonyl group
- Number of carbon
- Number of sugar units
Classification of CHO based on the number of sugar units:
Monosaccharides
Disaccharides
Polysaccharides
Oligosaccharide
two monosaccharides are joined by a glycosidic linkage
Disaccharides
-simple sugars that cannot be hydrolyzed to a simpler form
- can contain 3 or more carbon atoms
Monosaccharides
-linkage of many monosaccharide units
-on hydrolysis, will yield more than 10 monosaccharides
Polysaccharides
2-10 carbohydrates
Oligosaccharide
example of aldose with 3 carbon
glyceraldehyde
example of ketose with 3 carbon
dihydrogenase
example of aldose with 5 carbons
ribose
example of ketose with 5 carbons
ribulose
example of aldose with 6 carbons
glucose
example of ketose with 6 carbons:
galactose
fructose
Monosaccharides:
oGlucose
oFructose
oGalactose
Disaccharides:
oSucrose
oLactose
oMaltose
most important CHO; major metabolic fuel
glucose
Fructose + Glucose
Sucrose
fibrous substances consisting of polysaccharides and forming the major constituent in the exoskeleton of arthropods and the cell wall of fungi
Chitin
Galactose + Glucose
Lactose
polysaccharides:
oStarch
oGlycogen
oChitin
Glucose + Glucose
Maltose
stored in liver and muscles
Glycogen
storage form of glucose in the body
Glycogen
breakdown of carbon or sugar
hydrolysis
bind polysaccharide and oligosaccharide
glycocidic acid