Table of contents

1. Introduction to Biochemistry4h 34m
2. Water3h 23m
3. Amino Acids8h 10m
4. Protein Structure10h 4m
5. Protein Techniques14h 5m
6. Enzymes and Enzyme Kinetics13h 38m
7. Enzyme Inhibition and Regulation 8h 42m
8. Protein Function 9h 41m
9. Carbohydrates7h 49m
10. Lipids5h 49m
11. Biological Membranes and Transport 6h 37m
12. Biosignaling9h 45m
Review 1: Nucleic Acids, Lipids, & Membranes2h 47m
Review 2: Biosignaling, Glycolysis, Gluconeogenesis, & PP-Pathway3h 12m
Review 3: Pyruvate & Fatty Acid Oxidation, Citric Acid Cycle, & Glycogen Metabolism2h 26m
Review 4: Amino Acid Oxidation, Oxidative Phosphorylation, & Photophosphorylation1h 48m

4. Protein Structure

Fibrous and Globular Proteins

Biochemistry

4. Protein Structure

Fibrous and Globular Proteins

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Multiple Choice

Why is collagen insoluble?

The polar side chains of its residues highly interact with water.

Its hydrophobic residues exposed on its surface do not fold away into a core in its linear structure.

Its long, linear structure increases its surface area, minimizing residue contact with water.

The lack of multiple secondary structures indirectly correlates with its lack of hydrophobic residues.

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Collagen is a structural protein that is primarily found in connective tissues. Its insolubility is a key feature that contributes to its structural role.

The primary structure of collagen consists of a repeating sequence of amino acids, often glycine-proline-X or glycine-X-hydroxyproline, where X can be any amino acid. This sequence forms a unique triple helix structure.

In the triple helix, the hydrophobic residues are exposed on the surface, which is unusual compared to globular proteins where hydrophobic residues are typically buried inside.

The linear and extended nature of the collagen triple helix increases its surface area, which minimizes the interaction of residues with water, contributing to its insolubility.

Unlike many proteins that have multiple secondary structures, collagen's structure is relatively uniform, which means there is less opportunity for hydrophobic residues to be sequestered away from water, further contributing to its insolubility.