amino acid oxidation

Question 1

are chemical reactions that form intermediates of a metabolic pathway.

Answer 1

anapldrotic reaction

Question 2

a non-amino acid cofactor that is tightly linked to an enzyme

Answer 2

prosthetic group

Question 3

true/false: there is a storage compartment for amino acids

Answer 3

false

Question 4

in the ________, free amino acids are transported through epithelial cells, enter blood capillaries and travel to the liver

Answer 4

small intestine

Question 5

_____ are the. building blocks in protein synthesis

Answer 5

amino acid

Question 6

true/false: if amine group is separated from the amino acid during metabolism (as ammonia) it can be toxic to the cell

Answer 6

true

Question 7

how many amino acids are essential and must be broken down from protein in our diet?

Answer 7

9

Question 8

during ammonia toxicity, neuronal impairments can arise due to depleted levels of alpha-ketoglutarate. why would this impair the function of neutrons?
a) alpha-ketoglutarate is required for glycolysis
b) alpha-ketoglutarate is a key intermediate in the CAC
c) alpha-ketoglutarate is an antioxidant
d) alpha-ketoglutarate is required for the production of ketone bodies

Answer 8

b

Question 9

what two things must occur in order to prevent ammonia toxicity?

Answer 9

• ammonia must be removed from the amino aicd
• ammonia must be sent to the liver to be metabolized into a less toxic substance (urea)

Question 10

these reactions transfer amino groups from an amino acid to a keto acid

Answer 10

transanimation reactions

Question 11

what cofactor do transanimation reaction usually require

Answer 11

vitamin B6 (pyridoxine)

Question 12

are transanimation reactions usually reversible or irreversible?

Answer 12

reversible

Question 13

true/false: malate-asparate shuttle relies on a transaminase

Answer 13

true

Question 14

cells contain different transaminases that differ in their ______ for the L-amino acid

Answer 14

specificity

Question 15

all enzyme-catalyzed aminotransfersae reactions remove amino groups from amino acids, producing what byproduct that is important during metabolic stress?
a) pyruvate
b) a hydride and a H+
c) one of the ketone body molecules
d) fumerate
e) an alpha-keto acid

Answer 15

e

Question 16

this is used as a prosthetic group by all aminotransferases. it carries amino groups at the active side and transfers the amino group to alpha-keto acid

Answer 16

pyridoxine/pyridoxal phosphate (PLP)

Question 17

which statement about pyramidal phosphate (PLP) is false?
a) it is a coenzyme form of vitamin B6
b) all aminotransferases use it as a prosthetic group
c) it is only used by transaminases and by no other enzymes
d) it recieves amino groups in transamination reactions

Answer 17

c

Question 18

where does oxidative deamination of glutamate occur

Answer 18

in the mitochondrial matrix (free ammonia in the cytoplasm would damage the cell)

Question 19

what enzyme is used to catalyze the oxidative deamination of glutamate

Answer 19

L-glutamate dehydrogenase

Question 20

what is the product of the oxidative deamination of glutamate by L-glutamate dehydrogenase and where can it be used

Answer 20

alpha-ketoglutarate, enters the CAC or glucose synthesis

Question 21

transdeamination involves
a) the alpha-amino acids from nearly all amino acids being transferred to glutamate by transaminations, followed by the release of NH4+ from glutamate by L-glutamate dehydrogenase
b) release of alpha-amino groups from nearly all amino acids by L-amino acid dehydrogenase’s
c) release of alpha-amino groups from nearly all amino acids by L-amino acid deaminase
d) the combined actions of transaminase and glutamine synthetase

Answer 21

a

Question 22

glutamate dehydrogenase:
a) converts glutamate to glutamine
b) converts glutamine to glutamate
c) converts glutamate to aspartate
d) dominates glutamate to alpha-ketoglutarate
e) transmainates alpha-ketoglutarate to glutamate

Answer 22

d