Initial binding of ligand to a receptor tyrosine kinase receptor results in receptor _______________ and ___________________ of receptor tyrosine kinases. Exachange of GTP for GDP/Activation of alpha subunit Binding; Inactivation Dimerization/Trans-autophosphorylation Phosphorylation; Down-regulation When the special pair in a photosystem is excited by a quantum of light, charge separation can occur. Where does this take place? What is the charge of the ionized chlorophyll? In the reaction center; positive In the antenna complex; positive In the reaction center; negative In the antenna complex; negative
