A coenzyme that is derived from riboflavin and serves as a cosubstrate for enzymes that catalyze certain oxidation-reduction reactions is:
A. coenzyme A B. NAD C. NADP D. ATP E. FAD
When the inactive protein is combined with its specific cofactor, an active form created is called the:
A. coenzyme B. holoenzyme C. apoenzyme D. prosthetic group E. zymogen
Which of the following coenzymes contains an adenine nucleotide as part of its structure?
A. ATP B. NADP C. coenzyme A D. FAD E. all of the above
Which of the following is not a function for nucleotides in living cells?
A. linkage of lipid-anchored membrane proteins
B. components of coenzymes
C. activators of G proteins
D. carriers of metabolic energy
E. second messengers in signal transduction pathways
Which of the following statements is false?
A. Nucleotides are molecules that contain a sugar, a nitrogenous base, and a phosphate.
B. Nucleosides contain a pentose and a nitrogenous base held to the pentose by a ̢-N-glycosidic bond.
C. Uracil and thymine are purines.
D. Kinases are enzymes that catalyze the transfer of a phosphoryl group, usually from ATP, to another compound.
E. Cyclic nucleotides such as cAMP and cGMP can act as second messengers in signal transduction pathways.
Which of the following statements is false?
A. Cellular reactions for which the steady state ratio of products to reactants, Q, is numerically very far from the equilibrium constant, Keq, are known as metabolically irreversible reactions.
B. Cellular reactions tend not to reach equilibrium. Instead, they occur at a steady state in which substrate is being supplied at about the same rate that product is being removed.
C. Metabolism is an inclusive term used to indicate all reactions carried out by living cells.
D. A catabolic pathway involves synthesis of complex molecules from smaller precursors.
E. The rate of a pathway can be slowed by the action of a product of the pathway, a process called feedback inhibition.