How Proteins Fold in 3D: Anfinsen, Levinthal, AlphaFold | Part 5 | Stryer Chapter 2

Part 5 of 5 of Stryer Biochemistry Chapter 2 (section 2.7), explained with 3D animation and labels. In this part: Anfinsen’s ribonuclease experiment: unfolding with urea and beta mercaptoethanol, and refolding Scrambled ribonuclease and why the native disulfides win Aggregation and chaperones Which amino acids prefer helices, sheets and turns (Table 2.3) Cooperative folding and the half folded solution Levinthal’s paradox and cumulative selection Nucleation condensation and the folding funnel Predicting structure: CASP and AlphaFold Misfolding, amyloid and Alzheimer disease Posttranslational modifications, GFP and protein cleavage Chapter summary Chapters: 0:00 2.7 Sequence determines structure 0:10 2.7 Ribonuclease 1:10 2.7 Denaturing ribonuclease 2:18 2.7 Sequence specifies conformation 3:38 2.7 Scrambled ribonuclease 5:07 2.7 Aggregation and chaperones 5:45 2.7 Self-check question 6:30 2.7 Propensities for helices, sheets, and turns 7:11 2.7 Table 2.3 7:30 2.7 Why these preferences? 8:32 2.7 Can we predict secondary structure? 10:05 2.7 Folding is cooperative 11:36 2.7 The half-folded solution 12:45 2.7 Levinthal’s paradox 14:25 2.7 Cumulative selection 15:17 2.7 Marginal stability 17:08 2.7 Figure 2.57: a folding pathway 18:01 2.7 The folding funnel 19:08 2.7 Predicting structure from sequence 20:37 2.7 CASP and AlphaFold 22:16 2.7 Misfolding and disease 24:33 2.7 Posttranslational modifications 25:58 2.7 Green fluorescent protein 27:04 2.7 Cleavage after synthesis 28:08 Summary Watch all 5 parts of this chapter in the playlist on my channel. Subscribe for more biochemistry explained in 3D. Based on Stryer Biochemistry, 10th edition, Chapter 2. Made for education. © 2026 Educationalogy. All rights reserved. Re-uploading without permission is not allowed. #Biochemistry #ProteinFolding #Anfinsen #LevinthalParadox #AlphaFold #Amyloid #Stryer #3DAnimation