Answer: Assist in proper protein folding and prevent aggregation.
- A Target and degrade misfolded proteins via the ubiquitin-proteasome pathway
- B Assist in proper protein folding and prevent aggregation
- C Actively translocate completed proteins across the ER and mitochondrial membranes
- D Initiate assembly of the ribosomal subunits at the start codon
Correct answer: B. Assist in proper protein folding and prevent aggregation
Explanation: Molecular chaperones (e.g., HSP70, HSP90) bind to exposed hydrophobic regions of newly synthesized or stress-denatured proteins, preventing misfolding and aggregation, and facilitate correct folding.
As substrate concentration rises, reaction rate increases steeply at first, then plateaus at Vmax once every enzyme molecule is working at full capacity; Km is the substrate concentration giving half-maximal rate, and a LOWER Km means the enzyme reaches that rate with less substrate (higher affinity).
Concept context
Carbohydrates, proteins, lipids, nucleic acids, and enzyme kinetics. Essential foundation for understanding metabolism.