PHA6112 LAB S2(Carbohydrates)

Which of the following words/phrases makes the statement FALSE?

Carbohydrates are the most important sources of energy. They are widely distributed in animals and also found in certain tissues such as liver and muscles.

• Most important sources of energy

• Widely distributed in animals

• Liver

• Muscles

Which of the following words/phrases makes the statement FALSE?

We can utilize the proteins even if we do not have carbohydrates. They also come in the form of dietary fibers.

• can

• Do not have carbohydrates

• Dietary Fibers

• Proteins

Match the following

• Oligosaccharides

• Simple sugar that cannot be hydrolyzed

• Polysaccharides

• 2-10 monosaccharide units

• Monosaccharides

• More than 10 monosaccharide units

Organize these options into the right categories

Groups:

(a) Sucrose

,

(b) Lactose

,

(c) Maltose

• Glucose + Fructose

• 
• a1 -> b2 glycosidic linkage

• a(1---4) glycosidic linkage

• Glucose + Galactose

• Glucose + Glucose

• 
• 
• b(1---->4) glycosidic linkage

Organize these options into the right categories

Groups:

(a) Molisch's Test

,

(b) Iodine Test

• Blue-Black Solution for Starch

• Red or Pink Solution for Glycogen

• 0.01M or 0.2% Iodine Solution

• Strong acid to dehydrate monosaccharide to produce furfural or hydroxymethylfurfural

• Presence of Carbohydrates

• Purple ring interphase

• H2SO4, EtOH, a-naphthol

• Presence of Starch

Match the following

• Acid Hydrolysis

• Incomplete hydrolysis that breaks specific bonds.

• Basic Hydrolysis

• Complete Hydrolysis that produces a monosaccharide product

• Enzymatic Hydrolysis

• Epimerizaton of aldoses and ketoses and aldose-ketose interconversion

Organize these options into the right categories

Groups:

(a) Benedict's Test

,

(b) Barfoed's Test

,

(c) Seliwanoff's Test

,

(d) Bial's Orcinol Test

• Pentoses are dehydrated into furfural which in turn condense with orcinol

• Differentiate between aldose and ketose

• Cherry-red solution for ketohexoses

• Brick Red Precipitate for all reducing monosaccharides that appears < 3 mins for monosaccharides

• For Reducing Sugars; more sensitive than fehling's

• Strong acid to dehydrate monosaccharide to produce furfural or hydroxymethylfurfural

• HCl, resorcinol

• Based on the reduction of cupric acetate by reducing monosaccharides and reducing disaccharides

• Cupric ions reduced to cuprous, forming Cu2O precipitate.

• Brick Red precipitate for all reducing sugars

• HCl, FeCl3, and orcinol

• CuSO4, Na2CO3, Sodium Citrate

• Brick red precipitate appears ~10 mins for disaccharides

• Blue-green solution for aldopentoses

• Cu(C2H3OO)2, acetic acid

Identify what word/phrase makes the statement FALSE?

In Fehling's test, Fehling's A contains cuprous sulfate, which is blue. Fehling's B is a clear liquid consisting of potassium sodium tartrate, and a strong alkali. Both of these tests produce a Reddish Brown Precipitate if aldehydes and alpha-hydroxy-ketones are present.

• Cuprous sulfate

• Potassium sodium tartrate

• Reddish Brown Precipitate

• Present

Which of the following statements is FALSE? (check all those that apply).

• 0.3% 1-napthyl EDTA and 5% Sulfuric acid it EtOH produces blue black spots.

• para-anisaldehyde is used as a visualizing agent and produces green colored spots based on the complex with sugar.

• Maltose is more polar than dextrin but less polar than glucose.

• Solvent systems used in TLC are Acetonitrile and Water (80:20) and Chloroform-Methanol-Water-Acetic Acid (30:20:5:5)