Chapter 10

Question 1

What are the building blocks of proteins?

Answer 1

Amino acids

Question 2

How many standard amino acids are there?

Answer 2

20

Question 3

True or False: Amino acids are linked together by peptide bonds to form proteins.

Answer 3

True

Question 4

What is the primary structure of a protein?

Answer 4

The linear sequence of amino acids

Question 5

What is the secondary structure of a protein?

Answer 5

Regular, repeated patterns of folding within localized segments of the polypeptide chain

Question 6

What are the two most common types of secondary structure in proteins?

Answer 6

Alpha helix and beta sheet

Question 7

What is the tertiary structure of a protein?

Answer 7

The overall 3D shape of a polypeptide chain

Question 8

What is the quaternary structure of a protein?

Answer 8

The arrangement of multiple polypeptide chains in a protein complex

Question 9

What is denaturation of a protein?

Answer 9

The loss of a protein’s native structure due to heat, pH changes, or other factors

Question 10

What is the function of chaperone proteins in protein folding?

Answer 10

To help other proteins fold correctly and prevent misfolding

Question 11

What is the difference between an essential and non-essential amino acid?

Answer 11

Essential amino acids must be obtained from the diet, while non-essential amino acids can be synthesized by the body

Question 12

Which amino acid is known as the ‘building block of life’?

Answer 12

Alanine

Question 13

What is the isoelectric point of an amino acid?

Answer 13

The pH at which an amino acid carries no net charge

Question 14

What is the primary function of proteins in the body?

Answer 14

To serve as structural components, enzymes, hormones, antibodies, and transport molecules

Question 15

What is the difference between a zwitterion and a free amino acid?

Answer 15

A zwitterion has both a positive and negative charge, while a free amino acid has one charge

Question 16

What is the significance of the R-group in an amino acid?

Answer 16

It determines the specific properties and function of each amino acid

Question 17

What is the difference between a hydrophobic and hydrophilic amino acid?

Answer 17

Hydrophobic amino acids repel water, while hydrophilic amino acids attract water

Question 18

What is a disulfide bond in protein structure?

Answer 18

A covalent bond between two sulfur atoms in two cysteine amino acids

Question 19

What is the role of proline in protein structure?

Answer 19

Proline disrupts the secondary structure due to its unique cyclic structure

Question 20

What is the significance of the glycosylation of proteins?

Answer 20

It plays a role in protein folding, stability, and recognition

Question 21

What is the Ramachandran plot used for in protein structure analysis?

Answer 21

To analyze the allowed regions of dihedral angles in a polypeptide chain

Question 22

What is the difference between a globular and fibrous protein structure?

Answer 22

Globular proteins are compact and water-soluble, while fibrous proteins are elongated and insoluble

Question 23

What is the significance of the N-terminus and C-terminus in protein structure?

Answer 23

They indicate the beginning and end of a polypeptide chain, respectively

Question 24

Which amino acid is commonly found in collagen?

Answer 24

Glycine

Question 25

What is the role of histidine in enzyme catalysis?

Answer 25

It acts as a general acid-base catalyst in enzyme reactions

Question 26

What is the role of asparagine in protein structure?

Answer 26

It is involved in protein folding and stability due to its ability to form hydrogen bonds

Question 27

How does pH affect protein structure?

Answer 27

Extreme pH values can disrupt protein folding and denature proteins

Question 28

What is the significance of the hydrophobic effect in protein folding?

Answer 28

Hydrophobic amino acids tend to cluster together to minimize contact with water, driving protein folding

Question 29

What is the difference between a primary and quaternary structure of a protein?

Answer 29

Primary structure is the linear sequence of amino acids, while quaternary structure involves the arrangement of multiple polypeptide chains

Question 30

What is the role of disulfide bonds in stabilizing protein structure?

Answer 30

Disulfide bonds covalently link cysteine residues to form loops or bridges in proteins

Question 31

What is the function of collagen in the body?

Answer 31

To provide structural support and strength to tissues like skin, bones, and cartilage

Question 32

What is the structure of an alpha helix in proteins?

Answer 32

A right-handed helical structure stabilized by hydrogen bonds between the carbonyl oxygen and amide hydrogen atoms

Question 33

What is the significance of beta turns in protein structure?

Answer 33

Beta turns reverse the direction of a polypeptide chain, allowing it to fold back on itself

Question 34

What is the difference between a peptide bond and a disulfide bond in protein structure?

Answer 34

Peptide bonds link amino acids in a polypeptide chain, while disulfide bonds covalently link cysteine residues

Question 35

What is the role of a hydrogen bond in protein structure?

Answer 35

Hydrogen bonds stabilize secondary structures like alpha helices and beta sheets in proteins

Question 36

What is the difference between a parallel and anti-parallel beta sheet in protein structure?

Answer 36

In a parallel beta sheet, adjacent strands run in the same direction, while in an anti-parallel beta sheet, adjacent strands run in opposite directions

Question 37

What is the significance of the Ramachandran plot in protein structure analysis?

Answer 37

It shows the allowed regions of dihedral angles in a polypeptide chain, helping to predict protein folding

Question 38

What is the role of hydroxyproline in collagen structure?

Answer 38

Hydroxyproline stabilizes the triple helix structure of collagen through hydrogen bonding

Question 39

What is the role of methionine in protein structure?

Answer 39

Methionine acts as the starting amino acid in protein synthesis and contains a sulfur atom for disulfide bond formation

Question 40

What is the significance of the quaternary structure in protein function?

Answer 40

It allows for the assembly of multiple protein subunits to create functional complexes

Question 41

What is the function of keratin in the body?

Answer 41

To provide structural support to hair, nails, and skin

Question 42

What is the role of serine in enzyme catalysis?

Answer 42

Serine can act as a nucleophile in enzyme reactions due to its hydroxyl group

Question 43

What is the significance of post-translational modifications in protein structure?

Answer 43

They can alter protein function, localization, stability, and activity

Question 44

What is the role of leucine in protein structure?

Answer 44

Leucine is commonly found in hydrophobic regions of proteins and plays a role in protein-protein interactions

Question 45

What is the difference between a domain and a motif in protein structure?

Answer 45

A domain is a functional unit of a protein with a specific structure and function, while a motif is a smaller structural element with a conserved sequence

Question 46

What is the role of lysine in enzyme catalysis?

Answer 46

Lysine can act as a nucleophile in enzyme reactions due to its positively charged amino group

Question 47

What is the significance of the disulfide bond in stabilizing protein structure?

Answer 47

Disulfide bonds covalently link cysteine residues to form loops or bridges in proteins

Question 48

What is the difference between a tertiary and quaternary structure in protein organization?

Answer 48

Tertiary structure refers to the 3D folding of a single polypeptide chain, while quaternary structure involves the assembly of multiple polypeptide chains