How is an IP3-triggered Ca2+ response terminated

问答题Why does a red blood cell membrane need proteins

问答题Should RGS (regulator of G protein signaling) proteins be classified as GEFs (guanine nucleotide exchange factors) or GAPs (GTPase activating proteins) Explain what role this activity plays in modulating G-protein-mediated responses in animals and yeasts.

问答题Transport by carrier proteins can be either active or passive, whereas transport by channel proteins is always passive. Explain your answer.

问答题The signaling mechanisms used by a steroid-hormone(固醇激素) receptor and by an ion-channel-linked receptor have very few components(组分). Can either mechanism lead to an amplification of the initial signal If so, how

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.