General Interview Questions - Protein Folding & Targeting Where in the cell does protein synthesis and folding occur? What are the physical factors that drive the folding of polypeptides? Why are chaperones often necessary for protein folding? Consider both a prokaryotic and a eukaryotic cell, where can a protein end up? What specifies the location of a protein? Probes: lots of vocabulary (see below) to draw out answers.

Concept Statements Emphasis in your teaching General importance 1. In aqueous solution, polypeptides will fold to minimize the interactions between their hydrophobic R-groups with water. Emphasized Mentioned Not Covered Critical Important Marginal 2. Generally this leads to a compact globular, rather than an extended, structure. Emphasized Mentioned Not Covered Critical Important Marginal 3. Generally, the native (functional) state of a protein is the state of lowest free energy. Emphasized Mentioned Not Covered Critical Important Marginal 4. Chaperones facilitate the process by which a polypeptide folds into its native state, primarily by unfolding incorrectly folded polypeptides. Emphasized Mentioned Not Covered Critical Important Marginal 5. Chaperones recognize incorrectly folded polypeptides by the fact that they have display hydrophobic R-groups on their surface. Emphasized Mentioned Not Covered Critical Important Marginal 6. Some chaperones catalyze proline-peptide bond isomerization or break cysteine disulfide bonds, thereby facilitating correct polypeptide folding. Emphasized Mentioned Not Covered Critical Important Marginal 7. Some chaperones can mediate the assembly of multipolypeptide proteins by binding and stabilizing polypeptides prior to their assembly with the 'final' partners. Emphasized Mentioned Not Covered Critical Important Marginal 8. The process of protein folding begins as the newly synthesized polypeptide emerges from the ribosomal tunnel; before that folding is sterically suppressed. Emphasized Mentioned Not Covered Critical Important Marginal 9. H-bonds that form between the -C=O and -NH groups of the peptide bond are responsible for the common secondary structural motifs of proteins, alpha-helices and beta-sheets. Emphasized Mentioned Not Covered Critical Important Marginal 10. In an alpha-helix, the R-groups of the amino acid residues point outward, perpendicular to the helix axis. In a beta-sheet, the R-groups alternate in pointing above and below the plane of the sheet. Emphasized Mentioned Not Covered Critical Important Marginal 11. The synthesis of all polypeptide begins in the cytoplasm. For many proteins that are inserted into the plasma (or internal cellular membranes), translation is regulated by specific signals. Emphasized Mentioned Not Covered Critical Important Marginal 12. Polypeptides and proteins are targeted to specific cellular compartments but signals encoded in their structure. In some cases these signals are cleaved away once the polypeptide reaches its target. Emphasized Mentioned Not Covered Critical Important Marginal your email for tracking & responding only   Where do you teach? Outside of the USA Alabama Alaska American Samoa Arizona Arkansas California Colorado Connecticut Delaware Dist. Columbia Florida Georgia Hawaii Idaho Illinois Indiana Iowa Kansas Kentucky Louisiana Maine Maryland Massachusetts Michigan Minnesota Mississippi Missouri Montana Nebraska Nevada New Hampshire New Jersey New Mexico New York North Carolina North Dakota Ohio Oklahoma Oregon Pennsylvania Puerto Rico Rhode Island South Carolina South Dakota Tennessee Texas Utah Vermont Virgin Islands Virginia Washington West Virginia Wisconsin Wyoming I do not teach I teach, but not biology I am researcher in the private sector I teach elementary secondary college level biology     I would add the following statement to the list:

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