Exp 4: Other Reactions Of Proteins

Front 1

Precipitates Proteins

Back 1

Inorganic Acids: H2SO4, HCl, HNO3

Orgnic Acid: Glacial HAc

Alkali: KOH

Front 2

Due to the presence of the amino group in their molecules

Back 2

Amino acids have basic properties and form insoluble salts with acids

Front 3

Proteins have a capacity of

Back 3

Behaving as an acid or base = can be precipitated by strong acids and alkalis

Front 4

Salt bridges result from

Back 4

Neutralization of an acid and amine on side chains

Front 5

Final interaction is ionic between --

Back 5

Positive ammonium group and the negative acid group

Front 6

Salt bridge / Salt bond denotes a

Back 6

Relatively weak ionic bond between positively charged amino acids (arginine or lysine) and negatively charged amino acids (aspartic acid or glutamic acid) in a protein

Front 7

Salt bridges contribute to

Back 7

Stability of protein structure

Front 8

Acids and bases distrupt salt bridges held together by

Back 8

Ionic charges

Front 9

This reaction occurs where the positive and negative ions in the salt change partners with the positive and negative ions in the new acid or base added

Back 9

Double Replacement Reaction

Front 10

Denaturation reaction on the salt bridge by addition of an acid results in a

Back 10

Further straightening effect on the protein chain

Front 11

Test for albumin in urine

Back 11

Heller's Test

Front 12

Hellers Test PR

Back 12

Presence of albumin is indicated by formation of a white ring at the junction of the solution and a concentrate solution of nitric acid which is slightly yellow because of nitro-derivatives of proteins given by aromatic amino acids

Front 13

What is produced at the point of contact? To what is it due?

Back 13

White ring at the junction of the solution and a concentrate solution of nitric acid which is slightly yellow because of nitro-derivatives of proteins given by aromatic amino acids

Front 14

Robert's Test PR

Back 14

White precipitation

Front 15

What is the composition of Robert's Reagent

Back 15

Nitric Acid and Magnesium Sulfate

Front 16

Metallic Salts used:

Back 16

Lead acetate

Mercuric Chloride

Silver Nitrate

Copper Sulfate

Ferric Chloride

Barium Chloride

Front 17

Heavy metal salts act to

Back 17

Denature Proteins

Front 18

Heavy metals usually contain

Back 18

Hg, Pb, Ag, Ti, Cd

Front 19

The reaction of a heavy metal salt with a protein usually leads to

Back 19

Insoluble metal protein salt

Front 20

The reaction of a heavy metal salt is used for its

Back 20

Disinfectant properties in external applications

Front 21

AgNO3 is used to

Back 21

Prevent gonorrhea infections in the eyes of new born infants

Treatment of nose and throat infections

Cauterize wounds

Front 22

Antidote for acute heavy metal poisoning

Back 22

Protein such as milk or egg white, then emetic to induce vomiting

Front 23

Denaturation of proteins involves the

Back 23

Disruption and possible destruction of both the secondary and tertiary structures

Front 24

Denaturation disrupts the

Back 24

Normal alpha-helix and beta sheets in a protein and uncoils it into a random shape

Front 25

Denaturation occurs because

Back 25

The bonding interactions responsible for the secondary structure and tertiary structure are disrupted.

Front 26

Four types of bonding interactions between side chains in tertiary structures

Back 26

Hydrogen Bonding

Salt Bridges

Disulfide bonds

NOn-polar Hydrophobic Interactions

Front 27

Most common observation in the denaturation process

Back 27

Precipitation or coagulation of the protein

Front 28

For what kind of metallic poisoning will egg albumin be a useful antidote?

Back 28

Lead and Mercury. Egg albumin has sulfur-containing proteins, which react with the heavy metals helping to keep them from reaction with similar proteins in the body

Front 29

Composition of Tanret's reagent

Back 29

Potassium Iodide in hot water

Front 30

Alkaloidal reagents used

Back 30

TCA

Tannic Acid

Phosphotungstic acid

Phosphomolybdic Acid

Wagner's Reagent

Meyer's Reagent

Front 31

Alkaloidal reagents precipitate proteins on the

Back 31

Acid side of their pI

Front 32

Isoelectric Point (pI)

Back 32

pH of a solution at which the net primary charge of a protein becomes zero.

Front 33

At a solution pH that is above the pI the surface of the protein is

Back 33

Predominantly negatively charged and therefore like-charged molecules will exhibit repulsive forces

Front 34

At a solution pH that is below the pI the surface of the protein is

Back 34

Predominantly positively charged and repulsion between proteins occurs

Front 35

pH of most proteins

Back 35

4-6

Front 36

Mineral acids (HCl, H2SO4) are used as

Back 36

Precipitants

Front 37

Greatest disadvantage to pI precipitation is the

Back 37

Irreversible denaturation caused by the mineral acids so pI is most often used to precipitate contaminant proteins rather than the target protein

Front 38

Give the rationale of the use of picric acid on burns and tannic acid for diarrhea

Back 38

Picric acid treats burns because they provide astringent effect on the tissues, diminish secretion of mucous membranes and prevent absorption of toxins

Tannic acid treats diarrhea

Front 39

Salting Out

Back 39

Most common method used to precipitate/separate proteins

Front 40

Proteins are less soluble at

Back 40

High salt concentrations

Front 41

Salting out is also used to

Back 41

Concentrate dilute solutions of proteins

Front 42

Diaysis can be used to

Back 42

Remove the salt if needed

Front 43

After protein oflding in aqueous solutions,

hydrophobic amino acids---

hydrophilic amino acids---

Back 43

Form protected hydrophobic areas

Interact with the molecules of solvation and allow proteins to form H bonds with the surrounding water molecules

Front 44

Essential amino acids not synthesized by the body

Back 44

Histidine

Isoleucine

Leucine

Lysine

Methionine

Phenylalanine