Difference Between Fibrous and Globular Proteins (University Level)

Chapter 1

Protein structure primer: primary → quaternary; domains; motifs

1

Primary structure: peptide bond, sequence directionality, and residue properties

2

Secondary structure: α-helix, β-sheet, turns; hydrogen-bond geometry

3

Tertiary structure: hydrophobic collapse, packing, disulfides, salt bridges

4

Quaternary structure & domains: oligomers, cooperativity, modularity

Chapter 2

Overall shape & architecture: elongated fibers vs compact folds

5

Borderline/combined cases: membrane proteins, multi-domain proteins, fibrillar assemblies

Chapter 3

Amino-acid composition & sequence patterns (what the sequences “look like”)

6

Repetitive motifs & low complexity in fibrous proteins (e.g., Gly-X-Y; heptad repeats)

7

Diverse composition in globular proteins: mixed polar/nonpolar residues enabling folding cores

Chapter 4

Solubility, surface chemistry, and interactions with water

8

Hydrophobic effect and why globular proteins often have hydrophobic cores

9

Why fibrous proteins are often insoluble: extended packing, crosslinking, supramolecular assembly

10

Exceptions and conditions: pH, ionic strength, chaotropes, and extracellular matrices

Chapter 5

Mechanical vs biochemical function: structure–function logic

11

Fibrous roles: tensile strength, elasticity, scaffolding (ECM and cytoskeleton)

2 subtopics

12

Extracellular matrix fibrous proteins: collagen, elastin, fibronectin (overview)

13

Cytoskeletal fibrous proteins: actin filaments, microtubules, intermediate filaments (overview)

14

Globular roles: enzymes, transport, signaling, regulation

15

Structure–function explanation patterns (how to justify “why this shape fits this role”)

Chapter 6

Stability, dynamics, and denaturation behavior

16

Thermodynamic stability vs kinetic stability; folding landscapes

17

Denaturation and proteolysis: accessibility, packing defects, and turnover rates

18

Aggregation and amyloid as a special “fibrous-like” state

Chapter 7

Canonical examples & how to compare them in exam answers

19

Case study: enzymes as globular proteins (active-site geometry; induced fit)