chemlab carbohydrates tests

molischs

test for carbohydrates

benedicts

test for reducing sugars

barfoeds

test for reducing monosaccharides

bials

test for pentose

seliwanoffs

test for ketose

galactaric

test for galactose

iodine

test for starch

molischs reagent

5% alpha naphtol + 95% ethyl alcohol

benedicts reagent

CuSO4 + Na2CO3 + Na citrate

barfoeds reagent

Cu(CH3-COO)2 +glacial acetic acid/ sodium acetate

bials reagent

orcinol/ 5-methyl-1,3-dihydroxy benzene

seliwanoffs reagent

resorcinol/1,3-didroxy benzene + dilute HCL

galactaric reagent

Concentrated HNO3

Iodine reagent

I2 in Kl

fermentation reagent

yeast

violet ring, all carbohydrates

molischs positive result

brick red- reducing sugar

barfoeds positive result

brick red- reducing monosaccharides

barfoeds positive result

blue-pentose(arabinose)

bials positive result

cherry red-ketose

seliwanoffs positive result

white precipitate-galactose

galactaric positive result

blueblack pp.-starch

Iodine positive result

bubbles-maltose

fermentation

polyhydroxy

signifies that the aldehyde or ketone group has several OH group present

amylose

straight chain starch

amylopectin

branch chain starch polymer

Na citrate

glucose

dextrose, blood, grape sugar

Mannose

bitter sugar

fructose

sweetest sugar

galctose

came from agaragar, least fermentable monosaccharide

maltose

glucose + glucose, malt sugar

lactose

milk sugar, glucose + galactose

sucrose

non- reducing disaccharide, glucose + fructose

sucrose

table, cane, beet, barley, maple sugar

glycogen

animal starch

reducing sugar

must have an aldehyde or ketone group not involved in the linkage(free anomeric)