固醇激素进行的信号传导, 是一对一的, 即激素与受体结合即进入细胞核, 通过与特定DNA序列作用, 启动基因表达, 所以没有扩增。但离子通道偶联受体进行的信号传导, 虽然参与的组分不多, 但通道打开时间, 将进入众多的离子, 这本身就是信号放大。
问答题The basic structure of biological membranes is determined by the lipid bilayer, but their specific functions are carried out largely by proteins. Explain your answer.
判断题电镜的波长与电压有关,电压越高,波长越短,分辨率越高。
判断题Because prokaryotic cells have neither mitochondria nor chloroplasts, they cannot carry out either ATP synthesis or photosynthesis.
问答题Discuss the following analogy(相似): “The differences between transporting a ligand by a channel or a carrier protein are like the differences between crossing a river by a bridge or a ferry(摆渡).
问答题EGTA chelates(螯合) Ca2+ with high affinity and specificity. How would microinjection(微注射) of EGTA affect glucagon-triggered breakdown of glycogen (糖原) in liver
问答题What functional roles do the ECM (细胞外基质)and cell wall share in common
判断题Atrial natriuretic peptides(心钠肽) bind to a receptor that activates a G protein,which in turn activates guanylyl cyclase(鸟苷环化酶) to produce cyclic GMP which then activates a cyclic GMP-dependent protein kinase (PKG).
判断题It is thought that extracellular ligand binding to a receptor tyrosine kinase activates the intracellular catalytic domain by propagating a conformational change across the lipid bilayer through the single transmembrane a helix.
判断题Protein kinase A itself is different in different cell types, whichexplains why the effects of cyclic AMP vary depending on the target cell.
判断题How is it that different cells can respond in different ways to exactly the same signaling molecule even when they have identical receptors