细胞为什么常用“磷酸化”来开关信号？
Why do cells commonly use phosphorylation to switch signals on and off?
激酶把磷酸基加到目标蛋白上，可改变其形状与活性，从而快速、可逆地开关信号；磷酸酶则去掉磷酸基使其关闭。这种可逆修饰让信号既灵敏又可控。
Kinases add phosphate groups to target proteins, changing their shape and activity to switch signals on; phosphatases remove the phosphate to switch them off. This reversible modification makes signaling both fast and controllable.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Alberts 等,《Molecular Biology of the Cell》第6版,Garland Science,2014
B. Alberts et al., Molecular Biology of the Cell, 6th ed., Garland Science, 2014
#磷酸化 #激酶 #可逆修饰
G蛋白偶联受体（GPCR）如何把信号传进细胞？
How do G-protein-coupled receptors (GPCRs) relay signals into the cell?
GPCR被配体结合后，会激活细胞膜内侧的G蛋白，G蛋白再激活或抑制下游效应酶（如腺苷酸环化酶），从而放大并传递信号。约三分之一的西药以GPCR为靶点。
When bound by a ligand, a GPCR activates an intracellular G protein, which then turns downstream effector enzymes (like adenylyl cyclase) on or off, amplifying and passing the signal. Roughly a third of medicines target GPCRs.
难度 专业 · 适合 高中(15-18)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Alberts 等,《Molecular Biology of the Cell》第6版,Garland Science,2014
B. Alberts et al., Molecular Biology of the Cell, 6th ed., Garland Science, 2014
#GPCR #G蛋白 #药物靶点
受体酪氨酸激酶（RTK）和生长因子有什么关系？
What is the link between receptor tyrosine kinases (RTKs) and growth factors?
生长因子（如EGF）结合RTK后，会使受体二聚并自身磷酸化，招募下游信号分子，促进细胞增殖。RTK过度激活与多种癌症有关。
Growth factors such as EGF bind RTKs, causing them to dimerize and autophosphorylate, which recruits downstream molecules and drives cell proliferation. Overactive RTKs are linked to many cancers.
难度 进阶 · 适合 初中(12-15)
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Alberts 等,《Molecular Biology of the Cell》第6版,Garland Science,2014
B. Alberts et al., Molecular Biology of the Cell, 6th ed., Garland Science, 2014
#RTK #生长因子 #细胞增殖
细胞内的“第二信使”是什么？请以cAMP为例说明。
What are intracellular 'second messengers,' and what is cAMP an example of?
第二信使是细胞内的小分子，负责把细胞膜收到的信号放大并扩散到细胞内部。cAMP就是典型的一种，它由ATP在腺苷酸环化酶作用下生成，进而激活蛋白激酶A。
Second messengers are small intracellular molecules that amplify and spread a signal received at the membrane. cAMP is a classic one, made from ATP by adenylyl cyclase, and it then activates protein kinase A.
难度 进阶 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Alberts 等,《Molecular Biology of the Cell》第6版,Garland Science,2014
B. Alberts et al., Molecular Biology of the Cell, 6th ed., Garland Science, 2014
#第二信使 #cAMP #蛋白激酶
什么是细胞信号通路？
What is a cell signaling pathway?
细胞信号通路是细胞接收外界信号（如激素、生长因子）后，通过一系列蛋白质依次激活，把信息从细胞膜传到细胞核、引发特定反应的链条。
A signaling pathway is a chain in which a cell receives an external signal (e.g. a hormone or growth factor) and relays it through a series of proteins to the nucleus, triggering a specific response.
难度 入门 · 适合 大众
CC BY 4.0 · 已核验 · Verified 2026-08-23
来源 · Source
Alberts 等,《Molecular Biology of the Cell》第6版,Garland Science,2014
B. Alberts et al., Molecular Biology of the Cell, 6th ed., Garland Science, 2014
#信号通路 #细胞通讯 #信号转导