Module 4

Question 1

What are the building blocks of proteins?

Answer 1

Amino acids

Proteins are linear polymers of amino acids that form three-dimensional structures with specific functions.

Question 2

What is the structure of an amino acid?

Answer 2

An amino acid consists of an a carbon connected by covalent bonds to an amino group, a carboxyl group, a hydrogen atom, and a side chain or R group.

The side chain or R group differentiates the 20 common amino acids.

Question 3

How many common amino acids are there?

Answer 3

20

The common amino acids differ in their R groups.

Question 4

How are amino acids categorized?

Answer 4

By the chemical properties of their R groups:
* Hydrophobic
* Hydrophilic (polar, acidic, basic)
* Special

This categorization helps in understanding the behavior of amino acids in proteins.

Question 5

What type of bond links successive amino acids?

Answer 5

Peptide bonds

Peptide bonds connect amino acids to form proteins.

Question 6

What type of reaction forms a peptide bond?

Answer 6

Dehydration reaction

A dehydration reaction involves the removal of a water molecule.

Question 7

What does the primary structure of a protein refer to?

Answer 7

Amino acid sequence

This sequence determines how a protein will fold and function.

Question 8

What are the two termini of a protein?

Answer 8

• Amino (N) terminus
• Carboxy (C) terminus

Directionality is crucial for protein structure and function.

Question 9

How does the primary structure of a protein affect its other structural properties?

Answer 9

Determines the other three structural properties

These properties include secondary, tertiary, and quaternary structures.

Question 10

What is the secondary structure of a protein primarily stabilized by?

Answer 10

Hydrogen bonds

Secondary structures include alpha helices and beta sheets.

Question 11

What is the tertiary structure of a protein?

Answer 11

Three-dimensional shape of a peptide

Tertiary structure is crucial for the protein’s functionality.

Question 12

What is quaternary structure in proteins?

Answer 12

Structure formed by two or more polypeptide subunits

This structure results in a functional protein.

Question 13

What are emergent properties in quaternary proteins?

Answer 13

Properties not present in individual units

These properties arise from the interactions of subunits.