MIDTERM: LAB SHEETS Flashcards
a 6- CARBON SUGAR with an ALDEHYDE
functional group
ALDOHEXOSE
example of ALDOHEXOSE
GLUCOSE
It is ANY SUGAR that is capable of acting as a REDUCING AGENT because it has a FREE ALDEHYDE GROUP or FREE KETONE GROUP; It is a CARBOHYDRATE that is OXIDIZED by a WEAK OXIDIZING AGENT in a basic aqueous solution.
REDUCING SUGAR
- a functional group consisting of a CARBON ATOM bonded to both an -OH (HYDROXYL) group and an -OR (ALKOXY) group; forms when an ALDEHYDE reacts with an ALCOHOL
HEMIACETAL
Iodine solution (iodine dissolved in
an aqueous solution of potassium
iodide) reacts with starch
producing a blue-black color.
I2 TEST
I2 TEST
Expected Observation (Positive):
Substance Indicated by a Positive Test:
~ BLUE-BLACK
~ STARCH
- a sensitive chemical test for all
carbohydrates - based on the dehydration of
the carbohydrate by sulfuric
acid to produce an aldehyde
(either furfural or a derivative),
which then condenses with the
phenolic structure resulting in a
colored compound
MOLISCH’S TEST
MOLISCH’S TEST
Expected Observation (Positive):
Substance Indicated by a Positive Test:
~ VIOLET PURPLE
~ ALL CARBOHYDRATES
- Reducing sugars are detected
through Copper reduction:
from Blue Cupric ion to
Cuprous dioxide (brick-red
precipitate) - _______ reagent (Copper
sulfate in alkaline solution):
isomeric transformation of
ketoses to aldoses
BENEDICT’S TEST
BENEDICT’S TEST
Expected Observation (Positive):
Substance Indicated by a Positive Test:
~ BRICK RED
~ ALL MONOSACCHARIDES AND MOST DISACCHARIDES, REDUCING SUGARS like Glucose
- Reagent: Resorcinol in 6M HCl/
H2SO4 - Dehydration (ketohexoses)
forming a hydroxymethylfurfural
that condenses with resorcinol
SELIWANOFF’S TEST
SELIWANOFF’S TEST
Expected Observation (Positive):
Substance Indicated by a Positive Test:
~ CHERRY - RED
~ KETOHEXOSES, DISTINGUISHES BETWEEN ALDOSE AND KETOSE SUGARS like Fructose
Reagent: Resorcinol, HCl, and
Ferric chloride
* pentose is dehydrated to form
furfural and the solution turns
bluish (precipitate may also
form)
BIAL’S ORCINOL
BIAL’S ORCINOL TEST
Expected Observation (Positive):
Substance Indicated by a Positive Test:
~ BLUE - GREEN
~ PENTOSES (ribose)
Reagent: Cupric acetate in
acetic acid (slightly acidic and
balanced so that is can only be
reduced by monosaccharides
but not by less powerful
reducing sugars),
* disaccharides may also react
but the reaction is much slower
* reduction of Copper(II) acetate
to Copper(I) oxide (Cu2O),
which forms a brick-red
precipitate
BARFOED’S TEST
BARFOED’S ORCINOL TEST
Expected Observation (Positive):
Substance Indicated by a Positive Test:
~ BRICK RED
~ MONOSACCHARIDES
- chemical/colorimetric estimation of cholesterol
- cholesterol is made to react with a strong concentrated acids to a give colored solution
- Reagents: acetic anhydride (solvent and dehydrating agent) and sulfuric acid (dehydrating and
- oxidizing agent)
- solution becomes red or pink, then purple, blue and finally ____________
~ LIEBERMANN-BURCHARD TEST
~ BLUISH-GREEN COLOR
test used to differentiate FRUCTOSE AND
GALACTOSE
SELIWANOFF’S TEST
test used to differentiate GLUCOSE AND RIBOSE
BENEDICT’S TEST
test used to differentiate GLUCOSE AND MALTOSE
IODINE TEST
enzyme responsible for STARCH HYDROLYSIS
AMYLASE
product of STARCH HYDROLYSIS
- MALTOSE AND GLUCOSE
2 main type of AMYLASES IN STARCH
HYDROLYSIS
- ALPHA AMYLASE
- BETA AMYLASE
How are CARBOHYDRATES formed in nature?
PHOTOSYNTHESIS. plants convert light energy to chemical energy in the form of carbohydrates, specifically glucose.
Reaction for the process of forming
CARBOHYDRATES in NATURE
6 CO2 + 6H2O + light energy ›C6H12O6 +
6O2
Are animals able to synthesize carbohydrates?
NO, but they convert non-carbohydrate
precursors to glucose through
GLUCONEOGENESIS to provide source
of energy and maintain stable blood
levels
TEST performed to identify DISACCHARIDES
BENEDICT’S TEST, detects REDUCING
SUGARS which includes many
DISACCHARIDES
An unknown carbohydrate solution tested + with Molisch’s reagent formed ppt with barfoed’s reagent within 3 minutes and turned blue when mixed with bial’s orcinol reagent, what is this Carbohydrate?
pentoses sugar (RIBOSE). + Molisch’s
test indicates carbohydrates, red
precipitate with barfoed’s reagent
indicates reducing sugar, blue-green
color with bial’s orcinol indicates pentose
sugar
erythrose is an?
ALDOTETROSE
erythrose will give what result in Molisch’s test and forming what color?
POSITIVE, PURPLE or VIOLET RING
erythrose will give what result in Barfoed’s test and forming what color and what does it indicate?
POSITIVE, RED, REDUCING SUGAR
erythrose will give what result in Benedict’s test and forming what color and what does it indicate?
POSITIVE, BRICK-RED, REDUCING
SUGAR
erythrose will give what result in Seliwanoff’s test and forming what color and what does it indicate?
POSITIVE, PINK COLOR
NEGATIVE , NO COLOR
What product is formed when the ALDEHYDE END of glucose is OXIDIZED?
GLUCONIC ACID
How do hexoses affect alkaline Cu2+ complex ions,and what use is made of this reaction?
- Reduction reaction is called FEHLING’S TEST.
- HEXOSES reduces alkaline copper and forms REDDISH copper oxide, indicating the presence of REDUCING SUGARS.
- used to detect reducing sugars in food, biological samples, and chemical analysis
Do all disaccharides act as reducing agents?
No, whether a disaccharide is a
reducing/non - reducing sugar depends on the
PRESENCE OR ABSENCE of FREE ALDEHYDE/KETONE GROUP
REDUCING DISACCHARIDES; have FREE
ALDEHYDE group
MALTOSE & LACTOSE
NON-REDUCING DISACCHARIDE; lacks FREE
ALDEHYDE/KETONE GROUP
FRUCTOSE
types of lipids present in egg yolk
- NON-POLAR LIPIDS
- TRIACYLGLYCEROLS POLAR LIPIDS
- PHOSPHATIDYLCHOLINE and
- SPHINGOMYELIN
test that DETECTS CHOLESTEROL by OXIDIZING it with ACETIC ANHYDRIDE and SULFURIC ACID; test vital for IDENTIFYING CHOLESTEROL
LIEBERMANN - BURCHARD TEST
reagent in liebermann-burchard test; ACETYLATES CHOLESTEROL
A. ACETIC ANHYDRIDE
B. SULFURIC ACID
C. PHTHALIC ANHYDRIDE
ACETIC ANHYDRIDE
reagent in liebermann-burchard test; DEHYDRATES mixture to INTENSIFY COLOR CHANGE
A. ACETIC ANHYDRIDE
B. SULFURIC ACID
C. PHTHALIC ANHYDRIDE
SULFURIC ACID
reagent in liebermann-burchard test; (optional) can ENHANCE COLOR DEVELOPMENT
A. ACETIC ANHYDRIDE
B. SULFURIC ACID
C. PHTHALIC ANHYDRIDE
PHTHALIC ANHYDRIDE
type of LIPID essential for various biological
functions in the body. CRUCIAL COMPONENT of CELL MEMBRANES and involved in the production of HORMONES, VITAMIN D, and BILE ACIDS that aid in digestion
CHOLESTEROL
CHOLESTEROL is transported in the bloodstream in the form of?
LIPOPROTEINS
2 types of CHOLESTEROL CARRIERS
low-density lipoprotein (LDL)
- High-density lipoprotein (HDL)
type of CHOLESTEROL CARRIER; BAD
cholesterol
LOW-DENSITY LIPOPROTEIN
type of CHOLESTEROL CARRIER; GOOD
cholesterol
type of CHOLESTEROL CARRIER; GOOD
cholesterol
good effects of cholesterol
- essential for building and maintaining cell
membranes - precursor for the synthesis of important
molecules (hormones, vitamin D, bile acids,
etc)
bad effects of cholesterol
- elevated levels of LDL leads to formation of
PLAQUE in ARTERIES (risk of atherosclerosis, heart disease, etc) - high levels of LDL associated with an increased risk of CARDIOVASCULAR DISEASES
GENETIC MUTATION in GBA gene; deficiency of
GLUCOCEREBROSIDASE ENZYME leads to LIPID
BUILD UP in organs
A. GAUCHER’S DISEASE
B. NIEMANN-PICK DISEASE
C. RESPIRATORY DISTRESS SYNDROME
D. TAY-SACHS DISEASE
GAUCHER’S DISEASE
genetic mutation in SMPD1 or
NPC1 genes; accumulation of/ build up of SPHINGOMYELIN in tissues causes ORGAN DAMAGE
A. GAUCHER’S DISEASE
B. NIEMANN-PICK DISEASE
C. RESPIRATORY DISTRESS SYNDROME
D. TAY-SACHS DISEASE
NIEMANN-PICK DISEASE
common in PREMATURE INFANTS, due to
inadequate LUNG SURFACTANT PRODUCTION;
insufficient surfactant leads to LUNG COLLAPSE and BREATHING DIFFICULTIES
A. GAUCHER’S DISEASE
B. NIEMANN-PICK DISEASE
C. RESPIRATORY DISTRESS SYNDROME
D. TAY-SACHS DISEASE
RESPIRATORY DISTRESS SYNDROME
genetic mutation in the HEXA gene; deficiency of HEXOSAMINIDASE A ENZYME leads to GM2
GANGLIOSIDE buildup in nerve cells, causing
NEURODEGENERATION
A. GAUCHER’S DISEASE
B. NIEMANN-PICK DISEASE
C. RESPIRATORY DISTRESS SYNDROME
D. TAY-SACHS DISEASE
TAY-SACHS DISEASE
deficiency of what enzyme leads to Tay-Sachs?
HEXOSAMINIDASE A ENZYME
deficiency of what enzyme causes gaucher’s
disease
GLUCOCEREBROSIDASE ENZYME
solvent migration of TLC (mobile phase)
RISE UP/MOVES UPWARD (ascending)
solvent migration of column chromatography (mobile phase)
solvent flows DOWNWARD/GRAVITY DRIVEN DOWN (descending)
stationary phase in TLC
THIN LAYER adsorbent material (silica
gel, aluminum, etc)
stationary phase in column chromatography
COLUMN PACKED with solid adsorbent
(silica gel, aluminum, etc)
type of support in TLC
flat support (glass or plastic plate)
type of support in column chromatography
cylindrical glass or plastic column
used in TLC to detect AMINO ACIDS and AMINES by forming COLORED PRODUCTS upon reaction
- enables the identification and visualization of these compounds.
NINHYDRIN
used in TLC to visualize NONVOLATILE
COMPOUNDS on the plate by forming VISIBLE
COMPLEXES / COLOR CHANGES, helping identify substances in the mixture
- used to detect the presence of nonpolar compounds like lipids
IODINE VAPOR
