Biochemistry 2280A Lecture Notes - Lecture 3: Elastin, Collagen, Hemoglobin

49 views4 pages

silverwolf688

30 Jan 2018

School

Department

Course

Professor

For unlimited access to Class Notes, a Class+ subscription is required.

Document Summary

Unit 1: fundamental concepts of biochemistry lesson 3: protein structure (sept. 12th 2017) Equivalent to: limited rotation due to the peptide bond, atoms involved are coplanar, restricts possible folding patterns of the chain, bonds that link the molecule to the alpha carbon do have rotation. Hydrogen bonds: formed when a hydrogen atom is sandwiched between two electron-attracting atoms (usually o or n) Tertiary structure: concerns the 3-d arrangement of a single polypeptide chain, stabilized by bonds between side chains (or side chain to backbone), gives overall shape of polypeptide. Stabilization of tertiary structure: one type of covalent bond, disulfide bond, between cysteine residues in distant parts of the protein, only form in oxidizing environments. Many types of hydrogen bonds stabilize tertiary structures: Conformational flexibilty and changes: proteins are not completely rigid structures, various types of motion possible depending on structure, often domains can move, connected by flexible linkers, conformational changes.

Related Questions

1. The level of protein structure that is stabilized primarilyby non-covalent interactions between the side chains within asingle polypeptide chain is refered to as its:

A) primary structure

B) secondary structure

C) tertiary structure

D) quaternary structure

E) none of the above

2. Collagen, a strong fibrous protein found in connectivetissue, bone, and the extracellular matrix, has a structure inwhich three left-handed helices wind around each other to form aright-handed triple helix. The primary structure of collagen has arepeat unit of -(Gly-X-Pro)- Which of the following bonds stabilizethe collagen triple helix? (mark all that apply)

A) Hydrogen bonds between hydroxyproline residues

B) Hydrogen bonds between N-H and C=O

C) Ionic bonds between amino acid side chains

D) Hydrogen bonds between charged amino acids

3. The non-covalent forces that stabilize the Beta-strandconformation of peptides include:

A) H-bonds between amide C=O and amide NH

B) Van der Waals packing between the peptide backbone atoms

C) Van der Waals packing due to side chain interdigitation

D) Only A and B above

E) None of the above

4. What is the approximate length difference of a 22-kDasingle-stranded ?-helical protein segment vs. a 22-kDasingle-stranded ?-strand protein segment? Assume a mean residuemass of 110 Da. Show work.

5. Circular dichroism measurements have shown that the peptidebackbone of poly-l-lysine (KKKKKKK) adopts a random coilconformation at pH 7.0, but becomes ?-helical as the pH is raisedabove 10. This observation is known as the

magentaotter572

Biochemistry 2280A Lecture Notes - Lecture 3: Elastin, Collagen, Hemoglobin

Document Summary

Get access

Related Documents

Biochemistry 2280A Lecture Notes - Lecture 3: Carboxylic Acid, Oligopeptide, Protein Folding

Biochemistry 2280A Study Guide - Midterm Guide: Glycogen Phosphorylase, Antigen, Pectin

Biochemistry 2280A Lecture 3: Biochemistry 2280A Topic 3: Protein Structure

Related Questions