Proteins

Question 1

A biological macromolecule containing 30-50 amino acids.

Answer 1

Proteins

Question 2

What is the bond joining the amino acids in a protein?

Answer 2

Peptide bond

Question 3

A type of protein that is insoluble in water.

Answer 3

Fibrous protein

Question 4

A type of protein that is generally soluble in water.

Answer 4

Globular protein

Question 5

What is the building block of protein?

Answer 5

Amino acids

Question 6

Components of amino acid.

Answer 6

1. Amino group
2. Carboxyl group
3. R group

Question 7

What is the most important property of an R group that determines the structure and function of a protein?

Answer 7

Polarity

Question 8

Compounds that have a positive charge on one atom and a negative charge on the other.

Answer 8

Zwitterions

Question 9

How many protein chains make up hemoglobin?

Answer 9

4

Question 10

What is the bond between an amine and carboxylic group?

Answer 10

Amide bond

Question 11

What do you call the shortest chains of amino acids?

Answer 11

Peptides

Question 12

A residue (amino acid) with the free a-COO group?

Answer 12

C-terminus

Question 13

A residue (amino acid) with the free a-NH3 group?

Answer 13

N-terminus

Question 14

True or False.

Polypeptide chains start with a C-terminus on the left.

Answer 14

False.

Polypeptide chains start with N-terminus on the left and the C-terminus on its right (end).

Question 15

The properties of proteins are based on what?

Answer 15

1. Peptide backbone

2. Side chains (R group)

Question 16

When will a protein have a net positive charge?

Answer 16

when the pH is below (less than) its isoelectric point

Question 17

When will a protein have a negative charge?

Answer 17

when the pH is above (greater than) its isoelectric point

Question 18

What determines the structure of a protein?

Answer 18

Its difference on the sequence of amino acids.

Question 19

A structure of a protein that describes the linear sequence of amino acids in polypeptide chains.

Answer 19

Primary structure

Question 20

What structure of a protein refers to the repeating patterns?

Answer 20

Secondary protein

Question 21

What structure of a protein describes its 3D conformation?

Answer 21

Tertiary structure

Question 22

It is the highest level of protein organization that applies to protein with more than one polypeptide chain.

Answer 22

Quarternary structure

Question 23

What are the two conformations under the secondary structure of proteins?

Answer 23

1. a-helix

2. β-pleated sheet

Question 24

Protein conformation that does not exhibit a repeated pattern.

Answer 24

Random coils

Question 25

What is the most stable protein structure?

Answer 25

Tertiary structure

Question 26

What type of chemical reaction is involved in the conversion of disulfide bonds to SH bonds of cysteine?

Answer 26

Reduction

Question 27

What type of chemical reaction is involved in the formation of disulfide bonds from SH groups of cysteine?

Answer 27

Oxidation

Question 28

In the tertiary structure of proteins which amino acid is involved in forming covalent bonds?

Answer 28

Cysteine

Question 29

A protein that contains hydroxylysine and hydroxyproline.

Answer 29

Collagen

Question 30

Proteins that contain non-amino acid portions (prosthetic group).

Answer 30

Conjugated proteins

Question 31

What are the components of fetal hemoglobin?

Answer 31

(2) alpha | (2) gamma

Question 32

What are the components of adult hemoglobin?

Answer 32

(2) identical alpha | (2) identical beta

Question 33

True or False. | Fetal hemoglobin has a greater affinity for oxygen than adult hemoglobin.

Answer 33

True

Question 34

Triple helix unit that constitutes the soluble form of collagen.

Answer 34

Tropocollagen

Question 35

What is the process that destroys the stabilizing structures of protein by any physical and chemical agent?

Answer 35

Denaturation

Question 36

Amino acids in which are precursors of norepinephrine and epinephrine.

Answer 36

phenylalanine and tyrosine

Question 37

In the stabilization of the tertiary structure, what bonding happens between polar groups on side chains or between side chains and the peptide backbone?

Answer 37

Hydrogen bonding

Question 38

In the stabilization of the tertiary structure, what interaction happens between 2 amino acids with ionized side chains?

Answer 38

Salt bridges

Question 39

What will happen to a zwitterion if HCl (strong acid) is added to its solution?

Answer 39

It will turn into a positive ion by lowering the pH.

Question 40

What will happen to a zwitterion if NaOH (strong base) is added to its solution?

Answer 40

It will turn into a negative ion by raising the pH.