Answer:
Final answer:
The unfolded protein response (UPR) deals with misfolded proteins in the ER and aims to restore normal function, while the heat shock response, triggered by high temperatures, activates heat shock proteins like HSP70 to refold misfolded proteins throughout the cell. The correct option is b.
Step-by-step explanation:
The UPR involves signaling mechanisms that seek to restore normal function by stopping protein translation, degrading misfolded proteins, and activating the production of molecular chaperones.
On the other hand, the heat shock response involves the activation and increased production of heat shock proteins (HSPs), which serve as molecular chaperones to refold misfolded proteins and protect the cells during conditions of thermal stress.
Heat shock proteins, such as HSP70, are released from the NR/HSP complex and are upregulated in response to heat stress. This response serves the essential role of refolding proteins that may have denatured or misfolded due to high temperatures, thus maintaining protein functionality and preventing aggregation.
In contrast, the UPR, which is localized to the ER, is not directly activated by temperature; rather, it is a response to the specific stress of misfolded proteins in the ER, aiming to re-establish homeostasis within this organelle. The correct option is b.