细胞生物学选择题
73. 下列通讯系统中, 受体可进行自我磷酸化的是( B )。
a. 鸟苷酸环化酶系统 b. 酪氨酸蛋白激酶系统
c. 腺苷酸环化酶系统 d. 肌醇磷脂系统
74. 表皮生长因子(EGF)的跨膜信号转导是通过( A )的方式实现的
a. 活化酪氨酸激酶 b. 活化腺苷酸环化酶 c. 活化磷酸二酯酶 d. 抑制腺苷酸环化酶
75. Which of the following statements about enzyme-linked receptor is false? D
A. An enzyme-linked receptor is a transmembrane domainreceptor, where the binding of an extracellular ligand causes enzymatic activity on the intracellular side.
B. A enzyme-linked receptor has an extracellular ligand-binding domain, a transmembrane domain, and an intracellular catalytic (enzyme) domain.
C. The signal transduction pathways of enzyme-linked receptor involve phosphorylation cascades.
D. Enzyme-linked receptor interacts with an intracellular protein called a "G-protein".
76. Which of the following is not a type of cell surface receptor? B
A) ion-channel linked receptor B) intracellular receptors
C) enzymic linked receptors D) G-protein-linked receptors
77. ______B_______ rely on ___________, such as Ca2+, cyclic GMP, phosphatidylinositol, and cyclic AMP, to activate (or inactivate) a variety of pathways within the cell.
A. Intracellular receptors; ligands
B. G-protein-coupled receptors; second messengers
C. enzyme-linked receptor; G-proteins
D. G-protein-coupled receptors; G-proteins
78. Which of the following statements about G-protein signaling pathways is false? C
A. The first second messenger to be identified was cAMP.
B. Most Ca2+ -mediated signal transduction cascades act through the protein calmodulin.
C. enzyme-linked receptors directly activate G-proteins, which in turn activate second messengers.
D. Inositol triphosphate (IP3) and diacylglyerol (DAG) act as second messenger in two branches of the phosphatidylinositol signaling pathway.
79. Which of the following IS NOT one of the major cytoskeletal elements? C
a) microtubules b) intermediate filaments c) myosin d) microfilaments
80. 下列物质中, ( C )抑制微丝的解聚。
A.秋水仙碱 B.紫衫酚 C.鬼笔环肽 D.细胞松弛素B