BIOCHEM LAB > MIDTERM: LAB SHEETS > Flashcards

MIDTERM: LAB SHEETS Flashcards

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1
Q

a 6- CARBON SUGAR with an ALDEHYDE
functional group

A

ALDOHEXOSE

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2
Q

example of ALDOHEXOSE

A

GLUCOSE

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3
Q

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.

A

REDUCING SUGAR

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4
Q
  • 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
A

HEMIACETAL

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5
Q

Iodine solution (iodine dissolved in
an aqueous solution of potassium
iodide) reacts with starch
producing a blue-black color.

A

I2 TEST

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6
Q

I2 TEST
Expected Observation (Positive):
Substance Indicated by a Positive Test:

A

~ BLUE-BLACK
~ STARCH

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7
Q
  • 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
A

MOLISCH’S TEST

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8
Q

MOLISCH’S TEST
Expected Observation (Positive):
Substance Indicated by a Positive Test:

A

~ VIOLET PURPLE
~ ALL CARBOHYDRATES

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9
Q
  • 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
A

BENEDICT’S TEST

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10
Q

BENEDICT’S TEST
Expected Observation (Positive):
Substance Indicated by a Positive Test:

A

~ BRICK RED
~ ALL MONOSACCHARIDES AND MOST DISACCHARIDES, REDUCING SUGARS like Glucose

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11
Q
  • Reagent: Resorcinol in 6M HCl/
    H2SO4
  • Dehydration (ketohexoses)
    forming a hydroxymethylfurfural
    that condenses with resorcinol
A

SELIWANOFF’S TEST

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12
Q

SELIWANOFF’S TEST
Expected Observation (Positive):
Substance Indicated by a Positive Test:

A

~ CHERRY - RED
~ KETOHEXOSES, DISTINGUISHES BETWEEN ALDOSE AND KETOSE SUGARS like Fructose

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13
Q

Reagent: Resorcinol, HCl, and
Ferric chloride
* pentose is dehydrated to form
furfural and the solution turns
bluish (precipitate may also
form)

A

BIAL’S ORCINOL

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14
Q

BIAL’S ORCINOL TEST
Expected Observation (Positive):
Substance Indicated by a Positive Test:

A

~ BLUE - GREEN
~ PENTOSES (ribose)

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15
Q

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

A

BARFOED’S TEST

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16
Q

BARFOED’S ORCINOL TEST
Expected Observation (Positive):
Substance Indicated by a Positive Test:

A

~ BRICK RED
~ MONOSACCHARIDES

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17
Q
  • 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 ____________
A

~ LIEBERMANN-BURCHARD TEST
~ BLUISH-GREEN COLOR

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18
Q

test used to differentiate FRUCTOSE AND
GALACTOSE

A

SELIWANOFF’S TEST

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19
Q

test used to differentiate GLUCOSE AND RIBOSE

A

BENEDICT’S TEST

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20
Q

test used to differentiate GLUCOSE AND MALTOSE

A

IODINE TEST

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21
Q

enzyme responsible for STARCH HYDROLYSIS

A

AMYLASE

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22
Q

product of STARCH HYDROLYSIS

A
  • MALTOSE AND GLUCOSE
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23
Q

2 main type of AMYLASES IN STARCH
HYDROLYSIS

A
  • ALPHA AMYLASE
  • BETA AMYLASE
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24
Q

How are CARBOHYDRATES formed in nature?

A

PHOTOSYNTHESIS. plants convert light energy to chemical energy in the form of carbohydrates, specifically glucose.

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25
Reaction for the process of forming CARBOHYDRATES in NATURE
6 CO2 + 6H2O + light energy ›C6H12O6 + 6O2
26
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
27
TEST performed to identify DISACCHARIDES
BENEDICT'S TEST, detects REDUCING SUGARS which includes many DISACCHARIDES
28
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
29
erythrose is an?
ALDOTETROSE
30
erythrose will give what result in Molisch's test and forming what color?
POSITIVE, PURPLE or VIOLET RING
31
erythrose will give what result in Barfoed's test and forming what color and what does it indicate?
POSITIVE, RED, REDUCING SUGAR
32
erythrose will give what result in Benedict's test and forming what color and what does it indicate?
POSITIVE, BRICK-RED, REDUCING SUGAR
33
erythrose will give what result in Seliwanoff's test and forming what color and what does it indicate?
POSITIVE, PINK COLOR NEGATIVE , NO COLOR
34
What product is formed when the ALDEHYDE END of glucose is OXIDIZED?
GLUCONIC ACID
35
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
36
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
37
REDUCING DISACCHARIDES; have FREE ALDEHYDE group
MALTOSE & LACTOSE
38
NON-REDUCING DISACCHARIDE; lacks FREE ALDEHYDE/KETONE GROUP
FRUCTOSE
39
types of lipids present in egg yolk
- NON-POLAR LIPIDS - TRIACYLGLYCEROLS POLAR LIPIDS - PHOSPHATIDYLCHOLINE and - SPHINGOMYELIN
40
test that DETECTS CHOLESTEROL by OXIDIZING it with ACETIC ANHYDRIDE and SULFURIC ACID; test vital for IDENTIFYING CHOLESTEROL
LIEBERMANN - BURCHARD TEST
41
reagent in liebermann-burchard test; ACETYLATES CHOLESTEROL A. ACETIC ANHYDRIDE B. SULFURIC ACID C. PHTHALIC ANHYDRIDE
ACETIC ANHYDRIDE
42
reagent in liebermann-burchard test; DEHYDRATES mixture to INTENSIFY COLOR CHANGE A. ACETIC ANHYDRIDE B. SULFURIC ACID C. PHTHALIC ANHYDRIDE
SULFURIC ACID
43
reagent in liebermann-burchard test; (optional) can ENHANCE COLOR DEVELOPMENT A. ACETIC ANHYDRIDE B. SULFURIC ACID C. PHTHALIC ANHYDRIDE
PHTHALIC ANHYDRIDE
44
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
45
CHOLESTEROL is transported in the bloodstream in the form of?
LIPOPROTEINS
46
2 types of CHOLESTEROL CARRIERS
low-density lipoprotein (LDL) - High-density lipoprotein (HDL)
47
type of CHOLESTEROL CARRIER; BAD cholesterol
LOW-DENSITY LIPOPROTEIN
48
type of CHOLESTEROL CARRIER; GOOD cholesterol
type of CHOLESTEROL CARRIER; GOOD cholesterol
49
good effects of cholesterol
- essential for building and maintaining cell membranes - precursor for the synthesis of important molecules (hormones, vitamin D, bile acids, etc)
50
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
51
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
52
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
53
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
54
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
55
deficiency of what enzyme leads to Tay-Sachs?
HEXOSAMINIDASE A ENZYME
56
deficiency of what enzyme causes gaucher's disease
GLUCOCEREBROSIDASE ENZYME
57
solvent migration of TLC (mobile phase)
RISE UP/MOVES UPWARD (ascending)
58
solvent migration of column chromatography (mobile phase)
solvent flows DOWNWARD/GRAVITY DRIVEN DOWN (descending)
59
stationary phase in TLC
THIN LAYER adsorbent material (silica gel, aluminum, etc)
60
stationary phase in column chromatography
COLUMN PACKED with solid adsorbent (silica gel, aluminum, etc)
61
type of support in TLC
flat support (glass or plastic plate)
62
type of support in column chromatography
cylindrical glass or plastic column
63
used in TLC to detect AMINO ACIDS and AMINES by forming COLORED PRODUCTS upon reaction - enables the identification and visualization of these compounds.
NINHYDRIN
64
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
BIOCHEM LAB
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