biolab midterms

Question 1

CH(NH2)COOH

Answer 1

Protein that consists of amino acids

Question 2

(?) link to each other when the carboxyl group of one molecule reacts with the amino group of another molecule.

Answer 2

Amino acids

Question 3

Basic building blocks of enzymes, hormones, proteins, and body tissues.

Answer 3

Amino acids

Question 4

compound consisting 2 or more amino acids.

Answer 4

Peptide

Question 5

have 10 or fewer amino acids.

Answer 5

Oligopeptides

Question 6

Peptides consisting more than 50 amino acids

Answer 6

Proteins

Question 7

Used for quantitative photometrical determination of total protein concentration. (Intensity of color that is produced)

Answer 7

Biuret Test

Question 8

Peptides and protein react with Cu2+ (Copper Iron) in alkalinity to create a (?)

Answer 8

blue violet color.

Question 9

Peptides and protein react with (?) in alkalinity to create a blue violet color.

Answer 9

Cu2+ (Copper Iron)

Question 10

Using (?) the aromatic rings of amino acids like tyrosine and tryptophan are nitrated.

Answer 10

65% Nitric Acid

Question 11

Nitro derivates show intensely (?)

Answer 11

yellow color.

Question 12

Biochemical test for the detection of amino acids containing aromatics

Answer 12

Xanthoproteic test

Question 13

Used to detect presence of soluble proteins

Answer 13

Millon’s Test

Question 14

Reddish-brown coloration or precipitate indicates the presence of tyrosine residue (Occurs in nearly all proteins)

Answer 14

Millon’s Test

Question 15

Sulfur-containing amino acids when boiled converts into an inorganic sulfide (Na2S, Sodium Sulfide) - Reacts with lead acetate to form a (?) - Cysteine and Cystine give positive result to the sulfur test.

Answer 15

black precipitate of PbS (Phosphate-Buffered Saline)

Question 16

(?) containing amino acids when boiled converts into an inorganic sulfide (Na2S, Sodium Sulfide) - Reacts with lead acetate to form a black precipitate of PbS (Phosphate-Buffered Saline) - Cysteine and Cystine give positive result to the sulfur test.

Answer 16

Sulfur

Question 17

● Test for indole ring of tryptophan condensed with glyoxylic acid in the presence of sulfuric acid ● Forms violet-colored complex

Answer 17

Hopkins-Cole Test

Question 18

When it reacts with Ninhydrin, a (?) complex is formed.
Test is given by ALL proteins

Answer 18

purple-blue

Question 19

disruption and possible destruction of both the secondary and tertiary structure.

Answer 19

Denaturation of Protein

Question 20

The (?) remains the same after the denaturation process.

Answer 20

primary structure

Question 21

Occurs between amide groups in the secondary protein structure

Answer 21

Hydrogen Bonding

Question 22

occurs in tertiary protein structures - In a variety of amino acid combinations

Answer 22

Hydrogen Bonding

Question 23

(?) denatures proteins by disrupting the side chain intramolecular hydrogen bonding.

Answer 23

Alcohol

Question 24

Gets disrupted by the addition of alcohol.

Answer 24

Hydrogen Bonding

Question 25

- Used as a disinfectant for the skin

Answer 25

70% Alcohol

Question 26

- Concentration of alcohol is able to penetrate the bacterial cell wall and denature the proteins and enzymes inside the cell wall.

Answer 26

70% Alcohol

Question 27

- Merely coagulates the protein on the outside of the cell wall

Answer 27

95% Alcohol

Question 28

- Prevents alcohol from entering the cell

Answer 28

95% Alcohol

Question 29

(?) can be used to disrupt hydrogen bonds and non-polar hydrophobic interactions. increases kinetic energy and cause molecules to vibrate rapidly causing bond disruption.

Answer 29

Heat

Question 30

Heat can be used to disrupt (?). - Heat increases kinetic energy and cause molecules to vibrate rapidly causing bond disruption.

Answer 30

hydrogen bonds and non-polar hydrophobic interactions

Question 31

Heat increases (?) and cause molecules to vibrate rapidly causing bond disruption.

Answer 31

kinetic energy

Question 32

● Tannate and Trichloroacetate are high molecular weight anions ● Negative charge of anions counteracts Positive charge of amino group in proteins, giving precipitate.

Answer 32

Alkaloidal Reagents

Question 33

(?) are high molecular weight anions

Answer 33

Tannate and Trichloroacetate

Question 34

Negative charge of anions counteracts Positive charge of amino group in proteins, giving (?)

Answer 34

giving precipitate.

Question 35

● Disrupt salt bridges

Answer 35

Inorganic Acids

Question 36

● Result from the neutralization of an acid and amine on side chains.

Answer 36

Salt Bridges

Question 37

- ionic between positive ammonium group - ionic between negative acid group

Answer 37

Positive interaction

Question 38

(?) disrupt salt bridges held together by ionic charges.

Answer 38

Inorganic acids

Question 39

Inorganic acids disrupt salt bridges held together by (?)

Answer 39

ionic charges.

Question 40

● Occurs when positive and negative ions in the salt change partners with the positive and negative ions in the new acid.

Answer 40

Double Replacement Reaction

Question 41

● Occurs in the digestive system, where acidic gastric juices cause the coagulation of milk

Answer 41

Double Replacement Reaction

Question 42

● Distribution of the solute between a polar liquid phase ● Strongly absorbed on the cellulose fibers of paper ● Moves up the paper, amino acid is carried to a particular position on paper.

Answer 42

Paper Chromatography

Question 43

- Depends on properties such as molecular weight, structure, shape, and polarity of the molecule

Answer 43

The relative affinity

Question 44

Higher affinity for mobile phase than stationary phase - Travels with solvent - Unimpeded by filter paper

Answer 44

Amino Acid Affinity

Question 45

- Tends to stick to paper - Travels more slowly than the solvent front.

Answer 45

Higher affinity for paper than the solvent

Question 46

An (?) that is highly soluble in the eluting solvent will have a higher affinity for the mobile phase than an amino acid that is less soluble in the solvent.

Answer 46

amino acid

Question 47

Ninhydrin reacts with amino acids to form a (?)

Answer 47

blue-violet compound

Question 48

The (?) defines the ratio of the distance moved by a particular component divided by the distance moved by the solvent

Answer 48

Rf value

Question 49

(?) and (?) give positive result to the sulfur test

Answer 49

cysteine and cystine