Biology, Eighth Edition (Raven)

Chapter 19: Cellular Mechanisms of Development

View the animation below, then complete the quiz to test your knowledge of the concept.


1.	The second messenger cAMP is synthesized by the enzyme

		A)	adenylyl cyclase.
		B)	cAMP phoshodiesterase.
		C)	ATPase.
		D)	ligase.
		E)	phosphorylase.

2.	Binding of a signal molecule to a cell surface receptor activates a ________, which in turn activates ________.

		A)	α-kinase ; phospholipase C
		B)	α-kinase ; adenylyl cyclase
		C)	α-kinase ; G-protein
		D)	G-protein ; α-kinase
		E)	G-protein ; phospholipase C

3.	Which of the following statements about inositol triphosphate is FALSE?

		A)	It is formed in the cytoplasm.
		B)	It is synthesized by a membrane-bound enzyme.
		C)	It is synthesized by the enzyme phosphatase.
		D)	It binds to and opens Ca²⁺ channels in the endoplasmic reticulum.
		E)	Choose this answer if all of the above are true

4.	Calcium ions serve as second messengers.

		A)	True
		B)	False

5.	The enzyme α-kinase adds phosphates to specific proteins.

		A)	True
		B)	False