Final answer:
The size limit of GroEL, HSP-70, and HSP-90 is represented by their approximate molecular weights, with GroEL having subunits around 57 kDa but forms an approximately 800 kDa functional complex, HSP-70 about 70 kDa, and HSP-90 around 90 kDa. Thus, Option A is the closest match.
Step-by-step explanation:
Understanding Heat Shock Proteins and GroEL Size Limits
The size limit of GroEL, HSP-70, and HSP-90 molecular chaperones are commonly noted based on their nominal molecular weights.
For GroEL, it is not merely about the individual subunit molecular weight but the total functional complex. GroEL functions as a large double-ring with a barrel-like structure, where each ring is composed of seven subunits.
The question seems to discuss the subunit weight, which is significantly larger than 60 kDa. In reality, the subunit size of GroEL is approximately 57 kDa; however, the functional GroEL complex (the tetradecamer) has a molecular weight around 800 kDa.
In contrast, HSP-70 has a molecular weight in the vicinity of 70 kDa, while HSP-90 is approximately 90 kDa. Therefore, if we're referring to individual chaperone proteins and not multimeric structures, the correct sizes align with Option A: GroEL: 60 kDa, HSP-70: 70 kDa, HSP-90: 90 kDa.
It is important to note that the actual molecular weights can be slightly different based on the specific family member or isoform, but the stated values provide a general guideline.