Question

What is a peptide? What is a polypeptide?

What is meant by the primary structure of a protein?

What is meant by the secondary structure of a protein?

What is meant by the tertiary structure of a protein?

What is meant by the quaternary structure of a protein?

Explain why cooking food, such as frying an egg, results in visible changes to texture, density, smell, taste, and appearance. *Denaturation

Discuss the relationship between protein structure and protein function?

Answer 1

A peptide bond is a covalent chemical bond linking two consecutive amino acid monomers along a protein chain.

A polypeptide is a long continous peptide chain of amino acids. The primary structure of protein is the sequence of amino acids making up the protein and involves the covalent bonds linking the residues together.

The secondary structure describes the local folding pattern of polypeptide backbone and is stabilized by hydrogen bonds in between them.

Tertiary structure describes the 3D arrangement of a polypeptide chain. It results from interaction between side chain.

Quarternary structure refers to the number and arrangement of individual polypeptide chains.

The heat of cooking denatures protein, such as cooked egg transforming from a gel like liquid to semisolid. It breaks down cell wall and makes vegetables softer and easier to eat. The denatured materials have changed physical properties.

The function of protein is determined by its shape and the shape is determined by its primary structure. The swquence of amino acida in a protein is determined by sequence of nucleotide in gene.