Ch. 4 - Protein StructureWorksheetSee all chapters
All Chapters
Ch. 1 - Introduction to Biochemistry
Ch. 2 - Water
Ch. 3 - Amino Acids
Ch. 4 - Protein Structure
Ch. 5 - Protein Techniques
Ch. 6 - Enzymes and Enzyme Kinetics
Ch. 7 - Enzyme Inhibition and Regulation
Ch. 8 - Protein Function
Ch. 9 - Carbohydrates
Ch. 10 - Lipids
Ch. 11 - Biological Membranes and Transport
Ch. 12 - Biosignaling
Clutch Review 1: Nucleic Acids, Lipids, & Membranes
Clutch Review 2: Biosignaling, Glycolysis, Gluconeogenesis, & PP-Pathway
Clutch Review 3: Pyruvate & Fatty Acid Oxidation, Citric Acid Cycle, & Glycogen Metabolism
Clutch Review 4: Amino Acid Oxidation, Oxidative Phosphorylation, & Photophosphorylation
Peptide Bond
Primary Structure of Protein
Altering Primary Protein Structure
Drawing a Peptide
Determining Net Charge of a Peptide
Isoelectric Point of a Peptide
Approximating Protein Mass
Peptide Group
Ramachandran Plot
Atypical Ramachandran Plots
Alpha Helix
Alpha Helix Pitch and Rise
Alpha Helix Hydrogen Bonding
Alpha Helix Disruption
Beta Strand
Beta Sheet
Antiparallel and Parallel Beta Sheets
Beta Turns
Tertiary Structure of Protein
Protein Motifs and Domains
Anfinsen Experiment
Protein Folding
Chaperone Proteins
Quaternary Structure
Simple Vs. Conjugated Proteins
Fibrous and Globular Proteins

Concept #1: Alpha Helix Hydrogen Bonding

Example #1: Which residue does the carbonyl group of the 21st residue of a 30 residue α-helix hydrogen bond to?

Practice: The oxygen-storage protein myoglobin has 8 α-helices in its single polypeptide chain. Its 67th residue is near the center of a 19 residue α-helix. Which residue does the amino group of myoglobin’s 67th residue hydrogen bond to?

Concept #2: Alpha Helix Dipole

Practice: True or False: Negatively charged residues near the α-helix N-terminal are stabilizing due to its net dipole.

Practice: Triose phosphate isomerase (TPI) is a crucial enzyme involved in the glycolysis pathway and contains 14 α-helices. Considering the net dipole of the α-helix, which of the following would be most destabilizing to TPI’s structure?

Practice: The hemagglutinin protein in influenza virus contains a remarkably long α-helix with 53 residues.

A. How long is the α-helix? _____________

B. How many turns does this α-helix have? _____________

C. How many hydrogen bonds are present in this α-helix? ______________

Practice: Which of the following statements about α-helices is false?