The Urea Cycle

Front 1

What enzymes are in the digestive tract that digest amino proteins?

Back 1

pepsin, trypsin, chymotrypsin, elastase

Front 2

Amino acids absorbed in portal vein and transported to the _______. From there they enter the general _________________.

Back 2

Amino acids absorbed in portal vein and transported to the liver. From there they enter the general bloodstream.

Front 3

Back 3

Front 4

Cellular proteins can be degraded by the ___________ after being ubiquinated.

Back 4

Cellular proteins can be degraded by the proteosome after being ubiquinated.

Front 5

Cellular proteins can be degraded by the proteosome after being ______________.

Back 5

Cellular proteins can be degraded by the proteosome after being ubiquinated.

Front 6

Each round of ubiquitin addition requires what cofactor?

Back 6

ATP becomes AMP and PPi, so two equivalents of ATP

Front 7

Degradation of amino acids involves the removal of the _________ group, which is converted to urea in humans, The remaining a-keto acid is converted to other compounds.

Back 7

Degradation of amino acids involves the removal of the a-amino group, which is converted to urea in humans, The remaining a-keto acid is converted to other compounds.

Front 8

Degradation of amino acids involves the removal of the a-amino group, which is converted to _______ in humans, The remaining a-keto acid is converted to other compounds.

Back 8

Degradation of amino acids involves the removal of the a-amino group, which is converted to urea in humans, The remaining a-keto acid is converted to other compounds.

Front 9

Back 9

Front 10

Back 10

Front 11

Back 11

Front 12

Transaminases use the cofactor _______________________.

Back 12

Transaminases use the cofactor pyridoxal-5'-phosphate (PLP).

Front 13

The PLP cofactor forms a _______ _______ with the amino acid, promotes deprotonation and stabilizes the resulting carbanion. Reaction with OH- releases the a-keto acid.

Back 13

The PLP cofactor forms a Schiff base with the amino acid, promotes deprotonation and stabilizes the resulting carbanion. Reaction with OH- releases the a-keto acid.

Front 14

The PLP cofactor forms a Schiff base with the amino acid, promotes __________ and stabilizes the resulting ____________. Reaction with OH- releases the a-keto acid.

Back 14

The PLP cofactor forms a Schiff base with the amino acid, promotes deprotonation and stabilizes the resulting carbanion. Reaction with OH- releases the a-keto acid.

Front 15

The PLP cofactor forms a Schiff base with the amino acid, promotes deprotonation and stabilizes the resulting carbanion. Reaction with OH- releases the __________ _______.

Back 15

The PLP cofactor forms a Schiff base with the amino acid, promotes deprotonation and stabilizes the resulting carbanion. Reaction with OH- releases the a-keto acid.

Front 16

The PLP ring acts as an _________ _______ to stabilize carbanion intermediate.

Back 16

Front 17

The PLP ring acts as an electron sink to stabilize ______________ intermediate.

Back 17

Front 18

Different transaminases exhibit specificity for the amino acid substrate that acts as the amino donor, but most accept only ______________ or _________________ as the amino receptor.

Back 18

a-ketoglutarate, oxaloacetate

Front 19

____________ ___________ can oxidatively deaminate glutamate, reducing ________ and producing NH4+ and a-ketoglutarate.

Back 19

Glutamate degydrogenase can oxidatively deaminate glutamate, reducing NAD+ and producing NH4+ and a-ketoglutarate.

Front 20

Glutamate degydrogenase can oxidatively deaminate glutamate, reducing NAD+ and producing _________ and ______________.

Back 20

Glutamate degydrogenase can oxidatively deaminate glutamate, reducing NAD+ and producing NH4+ and a-ketoglutarate.

Front 21

Glutamate dehydrogenase works in both directions.

When it goes from Glutamate to a-Ketoglutarate what is the cofactor?

Back 21

NAD+

Front 22

Glutamate dehydrogenase works in both directions.

When it goes from a-Ketoglutarate to glutamate what is the cofactor?

Back 22

NADP+

Front 23

What is the only enzyme known to use NAD+ in one direction and NADP+ in the other?

Back 23

Glutamate dehydrogenase

Front 24

Back 24

Front 25

Back 25

Front 26

Where do the two amine groups come from in urea?

Back 26

Free ammonia and aspartate

Front 27

The urea cycle which starts and ends with _________, uses carbamoyl phosphate, aspartate, and 2 ATP equivalents and produces urea and fumarate.

Back 27

The urea cycle which starts and ends with ornithine, uses carbamoyl phosphate, aspartate, and 2 ATP equivalents and produces urea and fumarate.

Front 28

The urea cycle which starts and ends with ornithine, uses _________________, ___________, and 2 _______________ and produces urea and fumarate.

Back 28

The urea cycle which starts and ends with ornithine, uses carbamoyl phosphate, aspartate, and 2 ATP equivalents and produces urea and fumarate.

Front 29

The urea cycle which starts and ends with ornithine, uses carbamoyl phosphate, aspartate, and 2 ATP equivalents and produces _______ and __________.

Back 29

The urea cycle which starts and ends with ornithine, uses carbamoyl phosphate, aspartate, and 2 ATP equivalents and produces urea and fumarate.

Front 30

The urea cycle "prepatory" (1) step uses __________________________________ to catalzye the reaction of NH3 and HCO3- with 2 ATP to form carbamoyl phosphate.

Back 30

The urea cycle "prepatory" (1) step uses carbamoyl phosphate synthetase to catalzye the reaction of NH3 and HCO3- with 2 ATP to form carbamoyl phosphate.

Front 31

The urea cycle "prepatory" (1) step uses carbamoyl phosphate synthetase to catalzye the reaction of __________ and ___________ with 2 ________ to form carbamoyl phosphate.

Back 31

The urea cycle "prepatory" (1) step uses carbamoyl phosphate synthetase to catalzye the reaction of NH3 and HCO3- with 2 ATP to form carbamoyl phosphate.

Front 32

The urea cycle "prepatory" (1) step uses carbamoyl phosphate synthetase to catalzye the reaction of NH3 and HCO3- with 2 ATP to form ______________________.

Back 32

The urea cycle "prepatory" (1) step uses carbamoyl phosphate synthetase to catalzye the reaction of NH3 and HCO3- with 2 ATP to form carbamoyl phosphate.

Front 33

In the urea cycle what molecule is transported into the mitochondria? out of the mitochondria?

Back 33

ornithine, citrulline

Front 34

Back 34

C and E

Front 35

Back 35

Substrate = asparate

A = transaminase

B = a-ketoglutarate

C = glutamate

Product = oxaloacetate

Front 36

Back 36

Substrate = asparate

A = transaminase

B = a-ketoglutarate

C = glutamate

Product = oxaloacetate

D = kinase

E = ATP

F = ADP and Pi

G = CO2