Question

Provide an overview of the structural classification of carbohydrates

Answer 1

Answer :- Carbohydrates are the most abundant biological molecules, function as energy source (glucose), structural component.

Classification:

1) simple
-monosaccharides
-disaccharides
2) complex
oligosaccharides
polysaccharides

monosaccharides : carbohydrates that cannot be hydrolyzed (digested) into simpler carbohydrates
-trioses, tetroses, pentoses, hexoses, heptoses, octoses
polyhdroxy aldoses or ketoses (functional groups)
examples: glucose (blood sugar), fructose (fruit sugar, sweetest), galactose.

disaccharides : two monosaccharides bonded together (glycosidic bond)
bond can be hydrolyzed by enzymes
ex:
lactose (milk sugar): glucose + galactose
beta 1 ---> 4 bond
maltose (seed or malt sugar): glucose + glucose
alpha 1--->4 bond
sucrose (table or cane sugar, second sweetest) = glucose + fructose
alpha 1--->2 bond.

oligosaccharides : 3-10 monosaccharides bonded together

polysaccharides -beyond 10 monosaccharides bonded together
example:cellulose (plant fiber): linear polyglucose (beta1--->4 bonds)
glycogen (highly branched (alpha 1-->4 and 1--->6 bonds) close to a million molecules bonded together
starch (storage form of glucose in plants): amylose linear (alpha 1---->4 bonds), amylopectin: branched alpha 1-4 and 1-6 bonds .

Based on functional group carbohydrates can be classified into :-

aldoses -carbohydrates that contain an aldehyde group as their most oxidized functional group

ketoses-those with a ketone group as their most oxidized functional group

aldohexose - a six-carbon sugar with an aldehyde group

ketopentose - a five-carbon sugar with a ketone group