Phosphorylation cascades involving a series of protein kinases are useful for cellular signal transduction because:
a. they are species specific.
b. they always lead to the same cellular response.
c. they amplify the original signal manyfold.
d. they counter the harmful effects of phosphatases.
e. the number of molecules used is small and fixed.

What best explains whether bromine (br) or neon (ne) is more likely to form a covalent bond? bromine forms covalent bonds because it has seven valence electrons, but neon has eight valence electrons and already fulfills the octet rule. bromine forms covalent bonds because it has many electron shells, but neon has only two electron shells and is tightly bound to its electrons. neon forms covalent bonds because it can share its valence electrons, but bromine has seven valence electrons and can gain only one more electron. neon forms covalent bonds because it has only two electron shells, but bromine has many electron shells and will lose electrons in order to fulfill the octet rule.