Post Lab Exp 2: Protein Denaturation

Question 1

What are the objectives of the Exp 2: Protein Denaturation

Answer 1

❏ To observe the effects of several denaturing reagents on a
protein sample
❏ To differentiate the effect of these denaturing reagents to the
protein sample
❏ To cite practical applications of these denaturing agents.

Question 2

Any modification in conformation not accompanied by rupture of peptide
bonds

Answer 2

Protein Denaturation

Question 3

Involves the disruption and possible destruction of both the secondary
and tertiary structures

Answer 3

Protein Denaturation

Question 4

Loss of Biological Activity of Protein

Answer 4

Denaturation

Question 5

Regains Activity of Protein

Answer 5

Renaturation

Question 6

The sequence of amino acids present in protein’s peptide chain or chains

Answer 6

Primary Structure

Question 7

The regularly repeating ordered spatial arrangements amino acids near each other in the protein chain.

Answer 7

Secondary Chain

Question 8

What are the Secondary Structure of Proteins

Answer 8

Alpha Helix
Beta Pleated Sheet

Question 9

The overall three-dimensional shape that results from the attractive forces between amino acid side chains

Answer 9

Tertiary Structure

Question 10

Types of chemical bonds that are targeted by denaturing agents In secondary structures –

Answer 10

hydrogen bonds are disrupted

Question 11

In tertiary structure there
are four types of bonding
interactions between “side
chains” including

Answer 11

❏ hydrogen bonding
❏ salt bridges
❏ disulfide bonds
❏ and non-polar hydrophobic
interactions

Question 12

Effects of Denaturation

Answer 12

❏ Decreased solubility
❏ Altered water binding capacity
❏ Loss of biological activity
❏ Destruction of toxins
❏ Improved digestibility
❏ Increased intrinsic viscosity
❏ Inability to crystallize

Question 13

Denaturing Agents

Answer 13

Heat
Alcohol
Strong Acids and Strong Bases
Heavy Metals
Alkaloidal reagent

Question 14

increases the kinetic
energy and causes the
molecules to vibrate so rapidly
and violently that the bonds
are disrupted

Answer 14

Heat

Question 15

Disrupts hydrogen
bonding
■ Denatures both
secondary and tertiary
structures

Answer 15

Alcohol

Question 16

also reducing agents/oxidizing agents that can disrupt the disulfide bonds in
protein structure.

salts are ionic, they disrupt salt bridges in proteins or replaces one metal with another

Answer 16

Heavy Metals

Question 17

disrupt salt bridges held together by ionic charges that can affect the
environmental pH of proteins.

Answer 17

acids and bases

Question 18

High molecular weight
anions
■ The negative charge of
these anions counteracts
the positive charge of the
amino group in proteins
disrupting salt bridges

Answer 18

Alkaloidal reagent