Final (ch 18)

Question 1

This is the only nitrogen that is available to living systems

Answer 1

NH3

Question 2

Nitrogen fixation converts N2 to this, with this enzyme

Answer 2

NH4+, nitrogenase

Question 3

This is an example of an inducible enzyme that is only made when needed

Answer 3

nitrate reductase

Question 4

NH4+ to NO2- is this process using this enzyme

Answer 4

nitrification

nitrate reductase

Question 5

NO2- to NO3- is this process using this enzyme

Answer 5

nitrification

nitrite reductase

Question 6

This is a metalloprotein containing Fe-S clusters and Fe-Mo cofactor

Answer 6

nitrogenase

Question 7

this many electrons are required for nitrogen fixation

Answer 7

8

Question 8

bacteria produce nitrate via

Answer 8

nitrification

Question 9

some organisms convert nitrate back to N2 via

Answer 9

denitrification

Question 10

produces glutamine from glutamate

Answer 10

glutamine synthetase (basic)

Question 11

produces glutamate from glutamine

Answer 11

glutamate synthase (acidic)

Question 12

N2 to NH4+

Answer 12

nitrogen fixation

Question 13

Synthetase uses this, synthase does not

Answer 13

ATP

Question 14

During glutamine synthetase reaction this happens

Answer 14

Glu is phosphorylated

ammonium ion displaces inorganic phosphate

Question 15

During glutamate synthase reaction this happens

Answer 15

nirtogen is assimilated into citric acid cycle intermediate to produce Glu
Gln is deaminated to produce a second Glu

Question 16

The conversion of alpha kg to glutamate is this type of reaction

Answer 16

transamination

Question 17

Transaminases use this as a cofactor

Answer 17

pyridoxal-5’-phosphate

Question 18

PLP is derived from this essential nutrient

Answer 18

pyridoxine (B6)

Question 19

What ammino acid is attached to the PLP in a typical transaminase

Answer 19

lysine

Question 20

This is the key to the mechansim behind transaminases

Answer 20

schiff base formation

Question 21

what coenzyme is required for the conversion of serine to glycine

Answer 21

tetrahydrofolate

Question 22

phenylketonuria results from a deficiency of this enzyme

Answer 22

phenylalanine hydroxylase

Question 23

what is the amino acid that is a precursor for the neurotransmitters epinephrine and norepinephrine

Answer 23

tyrosine

Question 24

denitrification is the conversion of this to this

Answer 24

nitrate to nitrogen gas

Question 25

AA with any of these three things are more difficult to synthesize

Answer 25

sulfur branched chains aromatic groups

Question 26

in plants and pacteria synthesis of aromatic AA involves formation of this

Answer 26

chorismate

Question 27

Tyr is produced from PhE via this

Answer 27

hydroxylation

Question 28

a compound diffusing directly from one active site to the other without entering the surrounding solven is called

Answer 28

channeling

Question 29

this process increases the rate of metabolic processes by preventing the lose of intermediate

Answer 29

channeling

Question 30

This is used in Trp synth

Answer 30

channeling

Question 31

This is not formed from carbohydrate metabolites

Answer 31

histidine

Question 32

Amino acids are the precursors of some of these, including

Answer 32

signaling molecules | GABA

Question 33

Catecholamines are derived from

Answer 33

amino acids

Question 34

this is the precursor of melatonin

Answer 34

serotonin

Question 35

giving rise to gluconeogenic precursors, citric acid cycle intermediates are an example

Answer 35

glucogenic

Question 36

giving rise to acetyl-CoA, used for ketogenesis or fatty acid synthesis, not used for gluconeogenesis

Answer 36

ketogenic

Question 37

These aa have ketogenic fates

Answer 37

leucine | lysine

Question 38

these aa have glucogenic and ketogenic fates

Answer 38

``` isoleucine phenylalanine threonine pryptophan tyrosine ```

Question 39

Some AA are converted to this via transamination

Answer 39

gluconeogenic substrates

Question 40

This is convered to pyruvate by a process that releases ammonia and sulfur

Answer 40

cysteine

Question 41

Enzyme that is lacking in people with phenylketonuria

Answer 41

phynylalanine hydroxylase

Question 42

phenylketonuria is the result of the buildup of these to substances

Answer 42

Phe | phenylpyruvate

Question 43

alkaptonuria

Answer 43

black urine disease

Question 44

approximately 80% of excess nitrogen is excretes as this

Answer 44

urea

Question 45

deposits of uric acid in the joints and extremities cause this

Answer 45

gout

Question 46

The urea cycle is linked to TCA by

Answer 46

fumarate

Question 47

review the urea cycle on pg 13

Answer 47

okay

Question 48

bacteria, fungi and some other organisms use this to breakdown urea

Answer 48

urease

Question 49

a coenzyme frequently encounted in transamination reactions is

Answer 49

pyridoxal phosphate

Question 50

This is not a glucogenic aa

Answer 50

leucine

Question 51

a molecule cynthesized in the mitochondrial matrix and transported to the cytosol for subsequent reaction is

Answer 51

citrulline

Question 52

how many atp equivalents are required to produce one molecule of urea from ammonia and aspartate

Answer 52

3

Question 53

These are three excreted forms of nitrogen

Answer 53

ammonia urea uric acid