本题目来源于试卷: Interaction & Interdependence C.4 Chemical Signaling，类别为 IB生物学
[单选题]
Which feature correctlyhdq8u(f7 tkk pvcr+*6 desl ) dfgxda k;cy1,3+gmcribes the binding of a ligand to a receptor?
A. Receptors can bind to any ligand.
B. Both the ligand and receptor must have a complementary shape.
C. All ligands can penetrate the cell to bind with intracellular receptors.
D. All ligands bind irreversibly to receptors.
参考答案: B
本题详细解析:
B Choice B is correct because both the ligand and receptor must have a complementary shape to bind together, just like enzyme substrate specificity. Choice A is incorrect because receptors bind to specific ligands and not any ligands. Choice C is incorrect because not all ligands can penetrate the cell to bind with intracellular receptors. Ligands have to be hydrophobic to enter the cell, and some ligands are hydrophilic, which means they will remain outside the cell. Choice D is incorrect because not all ligands bind irreversibly to receptors, some bind reversibly.
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