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

判断题There is no fundamental distinction between signaling molecules that bind to cell-surface receptors and those that bind to intracellular receptors.

判断题Water has a high specific heat.

判断题The density of water is less than the density of ice.