Physical properties of enzymes: with respect to dialysis across a typical semipermeable membrane (small-molecule cut-off), enzymes generally:

Introduction / Context:
Enzymes are macromolecules, usually globular proteins with molecular masses far above small solutes. Their behavior in techniques like dialysis and ultrafiltration depends on size relative to the membrane cut-off. Understanding this helps with purification and experimental design.

Given Data / Assumptions:

• Typical semipermeable dialysis membranes allow passage of small molecules (salts, metabolites) below a certain molecular-weight cut-off (e.g., 3–10 kDa).
• Most enzymes are tens to hundreds of kilodaltons.
• No denaturation or proteolysis is assumed (intact enzyme).

Concept / Approach:
Because enzymes are large proteins, they are retained by standard dialysis membranes while small molecules (substrates, cofactors, buffers) can pass through. This is why dialysis can be used to exchange buffer or remove salts while keeping the enzyme in the bag/tube.

Step-by-Step Solution:

Verification / Alternative check:
Protein purification manuals consistently specify dialysis for exchanging small solutes around proteins, confirming retention of enzymes inside the membrane.

Why Other Options Are Wrong:
Pass through: False for intact enzymes with typical MW cut-offs. Dissolve membrane: Enzymes are not detergents and do not dissolve cellulose/acetate membranes. None: Incorrect because a clear correct statement exists.

Common Pitfalls:
Confusing dialysis membranes with ultrafiltration devices having selectable cut-offs; in both cases, intact enzymes are typically retained unless using very large pores.

Final Answer:
not pass through semipermeable membrane