Protein Structure

What is the primary structure of a protein?

What is the characteristic shape of globular proteins?

What type of bonds are responsible for the secondary structure of proteins?

What is the characteristic of an a-helix structure?

What is the result of a change in the primary structure of a protein?

What is the level of protein structure that refers to the arrangement of multiple polypeptide chains?

What is the characteristic of a b-pleated sheet structure?

What is the shape of insulin and albumins?

What is the function of hydrogen bonds in the secondary structure of proteins?

What is the level of protein structure that refers to the shape of a polypeptide chain?

Protein Structure

Globular proteins have a spherical shape and are usually soluble in water, with examples being insulin and albumins.

Levels of Protein Structure

There are four levels of protein structure: primary, secondary, tertiary, and quaternary, with each level being more complex than the previous one.

Primary Structure

The primary structure of a protein refers to the specific sequence of amino acids in a polypeptide chain.
A protein can have one or more polypeptide chains.
Any change in the primary structure (i.e., the sequence of amino acids) creates a different protein.

Secondary Structure

The secondary structure of a protein refers to the shape of a long polypeptide chain.
There are two types of secondary structures: α-helix and β-pleated sheet structure.
These structures arise due to the regular folding of the polypeptide chain backbone due to hydrogen bonding between –NH– and –C=O groups of the peptide bond.
α-Helix is a common way in which a polypeptide chain forms all possible hydrogen bonds by twisting into a right-handed screw (helix) with the –NH group of each amino acid residue hydrogen bonded to the –C=O of an adjacent turn of the helix.
β-Pleated sheet structure involves peptide chains stretched out to nearly maximum extension and laid side by side, held together by intermolecular hydrogen bonds, resembling the pleated folds of drapery.

This quiz covers the different levels of protein structure, including primary, secondary, tertiary, and quaternary, and their characteristics. Learn about globular proteins, polypeptide chains, and more.