Experiment 5 - Carbohydrates Flashcards
energy storage for polysaccharide implants
starch
energy reserve for animals
glycogen
provides sugar for 24 - 36 hours when fasting
glycogen
scientific name of cassava
manihot esculenta
scientific name of potato
solanum tuberosum
isolation principle of starch
by selective dissolution since starch is slightly soluble in H2O
isolation principle of glycogen
- Homogenization
- 10% TCA
- 95% EtOH
- NaCl
isolation principle of glycogen that ruptures the membrane
homogenization
isolation principle of glycogen that removes protein by precipitation
95% EtOH & 10% TCA
isolation principle of glycogen by purifying the glycogen
95% EtOH
linear homoglycan of glucose connected by a1-4 linkages
amylose
branched homoglycan with approximately 1 in 25 glucose linked in both a1-4 (linear part) and a1-6 (branched part)
amylopectin
what hydrolysis?
- complete hydrolysis
- monosaccharide product
acid hydrolysis
what hydrolysis?
- incomplete hydrolysis
- breaks specific bonds
enzymatic hydrolysis
what hydrolysis?
- salivary amylase will break down a-1,4 glycosidic bonds
- yield a mixture of glucose, maltose, and other hydrolysates (oligosaccharides)
enzymatic hydrolysis
what hydrolysis?
- aldo/keto groups are sensitive to strong base attacks
basic hydrolysis
what hydrolysis?
- epimerization of aldoses and ketoses and aldose-ketose interconversion
basic hydrolysis
what qualitative test?
- detect presence of carbohydrates
Molisch’s test
what qualitative test?
- detect presence of polysaccharides
Iodine test
What type of reaction is iodine test?
complexation reaction (amylose)
what color does iodine (test for amylose) give off?
purple
positive result of Molisch’s test
purple ring at interphase
positive result of Iodine test
blue-black solution (starch-iodo complex)
red or pink solution (glycogen-iodo complex)
principle of Molisch’s test
Strong acid (H2SO4) to dehydrate monosaccharide to produce furfural of hydroxymethylfurfural
principle of iodine test
iodine slides into starch coil to give blue-black color
reagents of Molisch’s test
H2SO4, EtOH (ethanol), a-naphthol
reagent of iodine test
KI
detect reducing sugars
benedict’s test