Enzymes

Question 1

Enzymes act upon ________ to produce _______ .

Answer 1

Substrates; Products

Question 2

Enzymes transiently disrupt _______ .

Answer 2

Homeostasis

Question 3

What is the complementary class of enzymes of Cyclases?

Answer 3

Phosphodiesterases

Question 4

What is the complementary class of enzymes to synthases?

Answer 4

Proteases, Lipases

Question 5

What is the complementary class of enzymes of Kinases?

Answer 5

Phophostases

Question 6

What is the function of Cyclases?

Answer 6

production of cyclic nucleotides

Question 7

Calmodulin

Answer 7

An endogenous calcium binding protein that can bind 4 Ca2+ ions; can also be a signaling molecule; activates AC

Question 8

Forskolin

Answer 8

A plant derived phorbol ester toxin; activates AC

Question 9

PKA

Answer 9

cAMP dependent protein kinase; binding 2 molecules of cAMP to each of the 2 regulatory subunits of PKA releases the 2 catalytic subunits

Question 10

How many classes of phosphodiesterases are there?

Answer 10

7

Question 11

What does a phosphodiesterase convert cAMP/cGMP to?

Answer 11

5’ cAMP/cGMP

Question 12

What are some inhibitors of phosphodiesterases?

Answer 12

Caffeine, theophylline, IBMX, sildenifil (viagra), vardenafil (levitra), tadalafil (cialis)

Question 13

NOS produces NO and is an example of a ______.

Answer 13

Synthase (nitric oxide synthase)

Question 14

NO is a ________ neurotransmitter.

Answer 14

Retrograde; it goes from the post synaptic cell to the pre synaptic cell

Question 15

PLC is an example of a _________.

Answer 15

Phosphotase

Question 16

What does PLC do?

Answer 16

Cleaves PIP2 into DAG and IP3

Question 17

PKC is an example of a _________.

Answer 17

Kinase

Question 18

What activates PKC?

Answer 18

DAG, free Ca2+, and ATP

Question 19

What are the isoforms of PKC?

Answer 19

α, β, γ, ε, ζ

Question 20

The ____________ of different isoforms of PKC are highly conserved.

Answer 20

Catalytic domains

Question 21

Active PKC is membrane bound because

Answer 21

DAG is required for its activation, and DAG is membrane bound

Question 22

IP3 activates

Answer 22

An intracellular IP3 receptor

Question 23

There are __________ of Ca2+ ions in the ER.

Answer 23

Hundreds of millions

Question 24

Calcium ATP-ase (the calcium pump) pumps Ca2+ _________ the ER.

Answer 24

Into

Question 25

The IP3 receptor _________ Ca2+ sequestered within the ER

Answer 25

Releases

Question 26

The ER ATP-ase is activated by ______.

Answer 26

CaM

Question 27

Enzymes are catalysts; they lower the ______ of a reaction.

Answer 27

Activation Energy