Answered: Intramolecular ______ are responsible…

9th Edition

ISBN:9781319114671

Author:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Publisher:Lubert Stryer, Jeremy M. Berg, John L. Tymoczko, Gregory J. Gatto Jr.

Chapter1: Biochemistry: An Evolving Science

Section: Chapter Questions

Problem 1P

Related questions

Question

Intramolecular ______ are responsible for formation of the most common three-dimensional shape in proteins, the alpha helix.

a) van der waals forces

b) hydrogen bonds

c) covalent bonds

d) ionic (electrostatic) interactions

Expert Solution

Answer

Proteins are unbranched polymers constructed from 22 standard a-amino acids. They have four levels of the structural organization. Primary structure, the amino acid sequence, is specified by genetic information. As the polypeptide chain folds, It forms certain localized arrangements of adjacent amino acids that constitute secondary structure. The overall three-dimensional shape that a polypeptide assumes is called the tertiary structure. Proteins that consist of two or more polypeptide chains (or subunits) are said to have a quaternary structure.
The primary structure (1° structure) of a polypeptide is its amino acid sequence. The amino acids are connected by peptide bonds. Primary structure of polypeptide determines the higher levels of structural organization.
The most common types of secondary structure (2 $°$ structure) are the a-helix and the $β$ -pleated sheet. Both a-helix and $β$ -pleated sheet patterns are stabilized by hydrogen bonds between the carbonyl and N-H groups in the polypeptide's backbone.