The document discusses several experiments characterizing lipids, carbohydrates, and salivary digestion. It provides details on solubility tests for lipids, qualitative tests to identify different carbohydrates including Fehling's test, Benedict's test, and the iodine test. It also lists the organic and inorganic components found in saliva and describes tests to identify them like using silver nitrate for chlorides and barium chloride for sulfates.

1. BIOCHEM LAB FINALS
Activity 5A “Characterization of Lipids”
A.SOLUBILITY
-Lipids are immiscible in water
-Immiscible in ordinary solvents
-Miscible in Chloroform (CHCl3), Ether
(C2H5O C2H5), Boiling alcohol (C2H5OH) and
other ORGANIC SOLVENTS.
B.TRANSLUCENT SPOT FORMATION
-Lipids don’t absorb heat to evaporate when
they in contact with paper or other surfaces.
Factors affecting formation of translucent
spot: Volatility and Number of Carbon atoms
Order of Formation of TS
1.Linseed
2.Coconut
3.Peanut
4.Corn
5.Olive
6.Cod Liver
C.REACTION OF FATS
-Fatty acids are carboxylic acids (organic
acid)/weak acids
-Neutral but when exposed to air becomes
acidic due to hydrolysis result is formation of
volatile fatty acids.
D.ACROLEIN FORMATION
-qualitative test for the presence of
GLYCEROL, free or esterified, based upon
its oxidative dehydration to ACROLEIN
when heated with Potassium Bisulfate
(KHSO4).
Chemical Reaction:
Activity 5B “Characterization of Lipids”
EMUSIFICATION OF FATS
-1 drop Coconut Oil + 1mL water
-1 drop Coconut Oil + 1mL water + 0.5%
Sodium Carbonate (Na2CO3) =
emulsification taken place
-1 drop Coconut Oil + 1mL albumin
Activity 5C “Qualitative Test for Cholesterol”
Preparation: Homogenize 20g Brain/Liver
tissue with 30mL acetone (C3H6O). Filter
homogenate on funnel. Suspend residue in
30mL acetone and filter (Repeat twice).
Combined filter contains neutral fats and
cholesterol. Evaporate 25mL acetone filter
on steam bath, dissolve in 5mL warm ethyl
alcohol (C2H5OH). Place in centrifuge tube
and add 1mL of 1% digitonin (C56H92O29) in
90% alcohol. Put stopper set aside for 3hrs.
white ppt. of cholesterol digitonin will be
tested by SALKOWSKI and LEIBERMANN-
BURCHARD. Neutral fats are on
supernatant, after digitonin precipitation.
Test for unsaturation.
SALKOWSKI TEST
-double bond in cholesterol rings + conc.
Inorganic acid = color product
-Conc. H2SO4 dehydrating agent
-BLUISH color bet. CHCl3 and H2SO4
LIEBERMANN-BURCHARD TEST

2. (Acetic Anhydride(CH3CO)2O or Ac2O)-
H2SO4)
-due to HYDROXYL GROUP (-OH) of
cholesterol + acetic anhydride + Conc.
H2SO4 = DEEP GREEN COLOR
Activity 6A “Qualitative Test for Diff. Types
of Carbohydrates”
MOLISCH TEST
-sugar = (+)
Reagent: a-naphthol and conc. H2SO4
Reaction: PURPLE RING bet. H2SO4 and
sugar
Positive: Glucose, Galactose, Fructose,
Maltose, Lactose, Sucrose, Glycogen,
Starch
ANTHRONE TEST
-reducing and non-reducing sugars = (+)
Reagent: Anthrone if sol’n is milky add
glacial CH3COOH or 50% H2SO4
Reaction: BLUE-GREEN COLOR
Positive: Glucose, Galactose, Fructose,
Maltose, Lactose, Sucrose, Glycogen,
Starch
PHENYLHYDRAZINE TEST (OSAZONE
FORMATION)
-presence of aldehyde or ketone group in
reducing sugars and (-OH group)
Reagent: Phenylhydrazine
Reaction: YELLOW-PALE ORANGE
CRYSTALS
Positive: Glucose, Galactose, Lactose,
Maltose
Activity 6B “Qualitative Test for
Carbohydrates”
MOORE’S TEST (Influence of Concentrated
Alkali)
-based of liberation of aldehydes which
subsequently polymerizes to form resinous
subs. “CARAMEL”
-test for reducing sugars except Sucrose
Reagent: Conc. NaOH
Reaction: YELLOW-ORANGE-FINALLY TO
DARK BROWN liberating a caramel odor,
more marked upon acidification
Positive: Glucose, Galactose, Maltose,
Fructose, Lactose
Negative: Sucrose, Glycogen, Starch
FEHLING’S TEST
-aldoses are easily oxidized to yield
carboxylic acids
-Cupric ion complexed with tartrate ion is
reduced to Cuprous oxide (brick red ppt.)
-Tartrate ion complexing agent keeps
copper ion solution. If absent cupric
hydroxide would precipitate from basic
solution
-Reduction of Cu2+
> Cu+
by reducing sugar
Reagent: Fehlings I and Fehlings II = deep
blue solution
Reaction: ORANGE-RED PPT. of Cu2O
Positive: Glucose, Galactose, Maltose,
Fructose, Lactose
Negative: Sucrose, Glycogen, Starch

3. BENEDICT’S TEST
-used to detect presence of all
monosaccharides and generally all reducing
sugars
Reagent: Sodium Citrate (Na3C6H5O7),
Sodium Carbonate, Sodium hydroxide and
Copper sulfate
Reaction: GREEN, YELLOW, ORANGE,
RED-BRICK RED PPT.
Positive: Glucose, Galactose, Maltose,
Fructose, Lactose
Negative: Sucrose, Glycogen, Starch
NYLANDER’S TEST
-used to detect presence of reducing sugars
except sucrose
Reagent: Sol’n of Rochelle Salt (potassium
sodium tartrate), KOH or NaOH and
Bismuth Subnitrate in water
Reaction: BLACK PPT.
Positive: Glucose, Galactose, Maltose,
Fructose, Lactose
Negative: Sucrose, Glycogen, Starch
PICRIC ACID TEST
-detects presence of reducing sugars
Reagent: Saturated Picric acid solution
(C6H3N3O7) and 5 drops 10% Na2CO3
Reaction: MAHOGANY RED SOL’N
Positive: Glucose, Galactose, Maltose,
Fructose, Lactose
Negative: Sucrose, Glycogen, Starch
BARFOED’S TEST
-reducing monosaccharides
Reagent: Cupric Acetate (Cu(OAc)2) and
Acetic acid (CH3COOH), HCl
Reaction: REDDISH PPT. of copper (I)
oxide
Positive: Glucose (Dextrose), Galactose,
Fructose (Levulose)
Negative: Maltose, Lactose, Surcose,
Glycogen, Starch
SELIWANOFF’S TEST
-dehydrated ketoses react with resorcinol to
produce deep cherry red color
-aldoses react to produce faint pink
Reagent: Resorcinol and Conc. H2SO4
Reaction: DEEP CHERRY RED=Fructose
and Sucrose
FAINT PINK=Glucose, Galactose, Maltose,
Lactose
IODINE TEST
-reacts with starch to form deep purple color
-heating and addition of sodium thiosulfate
makes sol’n lighter in color
Reagent: Iodine in Potassium Iodide (I2KI)
and Sodium Thiosulfate (Na2S2O3)
Reaction: DEEP PURPLE COLOR
MUCIC ACID TEST
-oxidation of galactose and hydrolysis of
lactose will yield insoluble mucic acid

4. -mucic acid crystal or galactaric acid melts
@ 213 degree Celsius insoluble in alcohol
and nearly in cold water
Reagent: Mucic acid (C6H10O8) and HNO3
Reaction: CRYSTAL FORMATION in
Galactose and Lactose
Activity 7 “Salivary Digestion”
REACTION OF SALIVA
Saliva at rest = pH 6-7
Stimulated = pH 8 up not exceed 12
-Phenolphthalein
Colorless-acid
Purple-basic pH 8-9
-Congo Red
Blue violet- pH 3
Red- pH 5
-Litmus paper
Blue-Red = Acid
Red-Blue = Basic
INORGANIC MATTER
-Chlorides- Silver Nitrate (AgNO3)
-Phosphates-Ammonium Molybdate
((NH4)2MoO4)
-Sulfates-Barium Chloride (BaCl3)
-Calcium-Ammonium oxalate ((NH4)2C2O4)
or Potassium oxalate (K2C2O4)
Other inorganic matters: Sodium,
magnesium, iodine, bicarbonate, potassium
ORGANIC MATTER
Mucus, Amylase, Lipase, Ptyalin, Proteins,
Antimicrobial enzymes