Biochem Lab Midterm
6 - mercaptoethanol (HS-CH2-CH2-OH)
disrupts disulfide bridges
Benedict's Test
- As in Fehling's test, the reducing sugar because of having potentially free aldehyde or keto group reduce cupric hydroxide in alkaline solution to red colored curpous oxide.
Ammonium Sulfate (NH4)2 SO4
- Blue Solution - Exp. 4, B. Salting Out
Test Tube 4 (Starch + Amylase + ethanol + Heat + iodine sol)
- Blue color - Exp. 5, Action of Pancreatin and Amylase
Sucrose (Fehling's Test)
- Blue solution - Exp. 6, Part 2 Reduction test: Fehling's Test
Lactose & Sucrose (Barfoed's Test)
- Blue solution - Exp. 6, part 2: Reduction Tests: Barfoed's Test
Sucrose (Benedict's Test)
- Blue soluton - Exp. 6, Part 2: Reduction test: Benedict's Test
Test Tube 1 (Starch sol + iodine sol)
- Blue to Black color - Exp. 5, Action of Pancreatin and Amylase
Glucose & Fructose & Lactose (Benedict's test)
- Brick red precipitate - Exp. 6, Part 2: Reduction Test: Benedict's Test
Glucose & Fructose & Lactose (Fehling's Test)
- Brick red precipitate - Exp. 6, Part 2 Reduction Test: Fehling's Test
Barfoed's Test
- Oxides monosaccharides but not oligosaccharides; disaccharides are less easily oxidized but are oxidized if they undergo prolonged heating.
Glucose & Fructose & Sucrose (Phloroglucinol - HCl test)
- Brown Solution - Exp. 6, D. Phloroglucinol
Fructose (Phenylhydrazine Test)
- Bundles of hay - Exp. 6, E. Phenylhydrazine Test
Glucose (Phenylhydrazine Test)
- Bundles of hay/needle-like - Exp 6, E. Phenylhydrazine Test
conc. KOH & Glacial HAc
- Coloress - Exp. 4, A.1. Influence of concentrated mineral and organic acids and alkalies
Monosaccharides
- Compose of one sugar units - simple sugar
Disaccharides
- Compose of two monosaccharides units
Xanthoproteic Test
- Denatured Protein (suspension 1): Yellow to Orange coloration - Coagulation Protein (suspension 2): Yellow to Orange coloration - Presence Tyrosine, Tryptophan, or Phenylalanine - Exp. 4, Denaturation & Coagulation of Egg Albumin - Color Reaction Test
Million's Test
- Denatured Proteins (suspension 1): Flesh to red precipitate - Coagulated Proteins (suspension 2): Flesh to red Precipitate - Presence of Tyrosine - Exp. 4, Denaturation & Coagulation of Egg Albumin - Color reaction Test
Biuret Test
- Denatured Proteins (suspension 1): Purple color - Coagulation Proteins ( suspension 2): Purple color - Peptide Bonds - Exp. 4, Denaturation & Coagulation of Egg Albumin - Color Reaction Test
Hopkins-Cole Test
- Denatured Proteins (suspension 1): Violet ring - Coagulation Protein (suspension 2): Violet ring - Presence of Tryptophan - Exp. 4, Denaturation & Coagulation of Egg Albumin - Color Reaction Test
Alcohols
- Disrupts H- Bonding
Denaturing Processes
- Disrupts H- Bonding - Heat - Mechanical Disruption - Drastic pH changes
Acids or Bases
- Disrupts H- Bonding and electrostatic interactions
Heavy metal ions
- Disrupts disulfide bridges and electrostatic interactions
UREA
- Disrupts hydrophobic and electrostatic interactions and H- bonding
SDS (sodium dodecyl sulfate)/ soap or detergents
- Disrupts hydrophobic interactions and H- Bonding
Glucose & Lactose (Seliwanoff's test)
- Faint pink - Exp. 6, C. Seliwanoff's Test
CuSO4
- Formation of Bluish white precipitate - Exp. 4, A.2. Precipitation by Metallic Salts
Alcohol + NaOH + Egg Albumin
- Formation of Turbid or Cloudy solution - Exp. 4, A.3. Precipitation by Alcohol
Picric Acid
- Formation of Yellow precipitate - Exp. 4, A.3. Precipitation of Alkaloidal Reagents
FeCl3
- Formation of Yellow precipitate - Exp. 4, A.2. Precipitation by Metallic Salts
Phosphomolybdic Acid
- Formation of Yellowish White precipitate - Exp. 4, A.3. Precipitation by Alkaloidal Reagents
Tannic Acid
- Formation of brown Precipitate - Exp. 4, A.3. precipitation by Alkaloidal Reagents
Alcohol + HCl + Egg Albumin
- Formation of clear and colorless solution - Exp. 4, A.3. Precipitation of alcohol
Pb(Ac)2 & AgNO3 & BaCl2
- Formation of white precipitate - Exp. 4, A.2 Precipitation by metallic salts
Trichloroacetic acid & Phospostungstic Acid
- Formation of white precipitate - Exp. 4, A.3. Precipitation of Alkaloidal Reagents
Alcohol + Egg Albumin
- Formation of white precipitate (maximum precipitation) - Exp. 4, A.3. Precipitation by Alcohol
95% Ethyl alcohol
- Glucose: slightly soluble - Fructose: slightly soluble - Lactose: slightly soluble - Sucrose: slightly soluble
0.25% HCl
- Glucose: soluble - Fructose: soluble - Lactose: soluble - Sucrose: soluble - Exp. 6 Part 1 - General Test for Carbohydrates, A. solubility
Suspension 2 (Coagulated), Suspension 1 + Heat, Suspension 2 + Heat
- Insoluble with HCl - Insoluble with HCl - Exp. 4, Denaturation & Coagulation of Egg Albumin - Solubility test
Phloroglucinol-HCl test
- It involve the formation of furfural derivatives in the presence of concentrated HCl. The test is used to specifically detect galactose and lactose in a sample solution.
Sucrose
- Made up of 6 - D - fructose linked to an Alpha - D - Glucose by a Beta (2-1) glycosidic bond - a non reducing sugar
Sucrose (Phenylhydrazine test)
- No Osazane crystals since sucrose is a non-reducing sugar - Exp 6, E. Phenylhydrazine Test
Oligosaccharides
- Oligo = "a few" - Usually 2 to 10 monosaccharides units
Lactose (Phenylhydrazine Test)
- Powder puff/puff-ball shape - Exp 6, E. Phenylhydrazine Test
Proteinuria
- Presence of Protein in the urine. - This may indicate the presence of damage to or disease on the kidneys
Albuminuria
- Presence of serum albumin, serum globulin, or other serum proteins in the urine. - This may be associated with kidney or heart disease, and may occur after strenuous exercise or after a long period of standing.
Test Tube 2
- Production of less bubbles - No reaction with lighted matchsticks - The yellow color was intensified with Benzidine
Test Tube 1
- Production of more bubbles - Production
Sodium Chloride (NaCl)
- Purple Solution - Exp. 4, B. Salting out
Glucose
- Purple to red violet - Exp 6, B. Molisch test
Lactose
- Purple to red violet - Exp 6, B. Molisch test
Fructose
- Purple to red violet - Exp. 6, B. Molisch test
Sucrose
- Purple to red violet - Exp. 6, B. Molisch test
Fructose & Sucrose (Seliwanoff's test)
- Red color - Exp 6, C. Seliwanoff's Test
Lactose (Phloroglucinol - HCl Test)
- Red solution - Exp 6, D. Phloroglucinol Test
Moore test
- Test for the presence of carbohydrates in a substance in the influence of a concentrated alkali
Picric acid test
- Test for the presence of reducing sugars - picric acid is a chemical compound formally called 2,4,6 - trinitrophenol (TNP). - a toxic yellow crystalline solid and one of the most acidic phenols
Fehling's Test
- The Blue alkaline cupric hydroxide present in solution, when heated in the presence of reducing sugars, gets reduced to yellow or red cuprous oxide and it gets precipitated. Hence, formation of the colored precipitated indicates the presence of reducing sugars in the test solution.
Molisch test
- is a general test for carbohydrates where sugars are mixed with alpha-naphthol, the test tube is inclined and about 1ml of concentrated sulphuric acid added along the sides of the tube.
Tollen's test
- is also known as silver mirror test - a qualitative test that distinguishes aldehydes from ketones on the principle that aldehydes are easily oxidized than ketones
Amylase
- is an enzyme that catalyzes the hydrolysis of starch into simple sugars
Renaturation
- The regaining of the correct secondary, tertiary, and quaternary structure after denaturation of a protein.
Denaturation
- Unfolding of Complex secondary, Tertiary, and quaternary structure of proteins - reversible process
Test Tube 5 (starch + pancreatin + Heat + iodine sol)
- Violet color - Exp. 5, Action of Pancreatin and Amylase
Test Tube 2 (Starch sol + pancreatin sol + Heat + iodine sol.) & Test Tube 3 (Starch sol. + Amylase sol. + Heat + iodine sol.)
- Violet to blue color - Exp. 5, Action of Pancreatin and Amylase
Robert's Test
- White ring or white precipitate - Exp. 4, A.1. Influence of concentrated mineral and organic acids and alkalies
Fructose
- a fruit sugar - is the simplest ketonic sugar - it is the sweetest naturally occurring carbohydrate
Maltose
- a reducing sugar - repeating disaccharides unit if starch - present in malt, the juice from sprouted barley and other cereal grains
Nylander's test
- a reduction test that used bismuth subnitrate which is reduced to Black precipitate bismuth when reacted with a reducing sugar
Polysaccharides
- are polymers of the simple usually more than 10 monosaccharides units
Enzymes
- are proteins that act as biological catalyst by reducing the activation energy of a chemical reaction
Lactose
- beta - galactopyranosyl - (1-4) beta - D - glucopyranoside - is the principal sugar present in milk; it makes up about 5 to 8 present of human milk and 4 to 6 percent of cow's milk
Glucose & Fructose (Barfoed's Test)
- brick red precipitate - Exp 6, part 2: Reduction Tests: Barfoed's Test
Trommer's Test
- is like the Benedict's test for reducing sugars only that it involves treating the sample with concentrated H2SO4 which results to acid hydrolysis of disaccharides forming monosaccharides
Glucose
- is the main type of sugar in the blood and is the major source of energy for the body's cells
Alkaloidal reagents
- combines with positively charged proteins and disrupts electrostatic interactions
Guanidium hydrochloride
- disrupts hydrophobic interactions, if detergent is charged, it can disrupt electrostatic interactions
conc. HNO3
- formation of Yellow precipitate - Exp. 4, A.1. Influence of concentrated mineral and organic acids and alkalies
Conc. H2SO4 & conc. HCl
- formation of white precipitate - Exp. 4, A.1. Influence of concentrated mineral and organic acids and alkalies
water
- glucose: freely soluble - fructose: freely soluble - lactose: freely soluble - Sucrose: freely soluble - Exp. 6 part 1: general test for carbohydrates. A. solubility
10% NaCl
- glucose: soluble - fructoe: soluble - lactose: soluble - Sucrose: soluble - Exp. 6. Part 1: General Test for carbohydrates, A. solubility
Galactose
- is a C-4 epimer of glucose - It is known as the brain sugar - it supports the brain development
Catalase
- is a common enzyme found in nearly all living organisms exposed to oxygen which catalyzes the decomposition of hydrogen peroxide to water and oxygen
Pancreatin
- mixture of several digestive enzymes produced by the exocrine cells of the pancrease. - It is composed of Amylase, Lipase, and Protease
Coagulation
- simple clumping together of dispersed chains of denatured protein - When heated further, the clumped chains become matted together in a mass which is insoluble
Suspension 1 (Denatured/Precipitated)
- soluble with HCl - Soluble with NaOH - Exp. 4, Denaturation & Coagulation of Egg Albumin - Solubility Test
Phenylhydrazine Reaction
- the ketoses and aldoses react with phenylhydrazine to produce a phenyldrazone which in turn reacts with another two molecules of phenylhydrazine to form the osazone
Seliwanoff's Test
- use to differentiate ketohexoses from aldehexoses - In the concentrated HCl ketones undergo dehydration to yield furfural derivatives more rapidly than do aldoses. These derivatives form complexes with resorcinol to yield deep red color
Salting Out
- use to seperate proteins based on their solubility in the presence of high concentration salt. - High concentration of salt like ammonium sulfate compete with proteins to bind to the water molecules. - This removes the water molecules from the protein and decreases it's solubility resulting in precipitation
Heller's Test
- used to detect the presence of Protein in urine - forms a yellow ring (due to the nitration of benzene ring of the amino acid present in the protein albumin - Exp. 4, A.1. Influence of concentrated mineral and organic acids and alkalies
Metallic Salts
used as antiseptic and germicides by precipitating bacterial proteins