Chapter 31 - Amino Acid Synthesis

Question 1

diazotrophic bacteria

Answer 1

organisms that can convert nitrogen gas to biochemically more useful, NH3

Question 2

The Haber process

Answer 2

allows for industrial fixation of nitrogen

Question 3

_________ and ________ are forms of nitrogen that are available to plants

Answer 3

ammonium and nitrates

Question 4

Nitrates are reduced to ________.

Answer 4

ammonium

Question 5

the nitrogenase complex

Answer 5

-consists of two proteins, reductase and nitrogenase

Question 6

reductase

Answer 6

provides e- with high reducing power

Question 7

nitrogenase

Answer 7

uses ,e- to reduce N2 to NH3

Question 8

The ammonia produced in plants is…

Answer 8

directly used by the plants

Question 9

The ammonia produced by nitrogen-fixing microorganisms in the soil is…

Answer 9

converted to nitrite, then to nitrate by other bacteria

-nitrate (NO3-) is taken up my plants and reduced to NH3

Question 10

Step 2: ___________ and _________ provide entry points to assimilation of ammonia to biomolecules

Answer 10

glutamate and glutamine

Question 11

glutamate dehydrogenase

Answer 11

NH4+ and aKG to glutamate

Question 12

glutamine synthetase

Answer 12

glutamate + NH4+ to glutamine

Question 13

glutamate synthase (last rxn)

Answer 13

aKG + glutamine to glutamate

Question 14

Step 3 of Assimilation of Nitrogen

Answer 14

glutamate and glutamine donate an amino group in other biosynthetic pathways

Question 15

The carbon skeletons for aa synthesis are provided by intermediates of…

Answer 15

the glycolytic pathway, citric acid cycle, and pentose phosphate pathway

Question 16

Glutamine synthetase is present in …

Answer 16

all organisms

Question 17

Gln synthetase is regulated by:

Answer 17

allosteric effectors (all 6 end product) and covalent codification (adenylation)

Question 18

adenylation

Answer 18

addition of AMP (occurs on a Try residue)

Question 19

structure of glutamine synthetase

Answer 19

12 identical subunits

Question 20

transamination rnx enzyme and coenzyme

Answer 20

• aminotransferase

- pyridoxal phosphate (vit B6)

Question 21

1-carbon transfer rxn enzyme cofactors (1C carriers and 1C donors)

Answer 21

• S-adenosyl methionine (SAM) donates methyl group

- tetrahydrofolate

Question 22

glutamine amidotransferase

Answer 22

transfer of an amino or amide group from glutamine

Question 23

1C transfer using SAM

Answer 23

methyl group transfers to a nitrogen or oxygen atom

Question 24

1C transfer rxns using tetrahydrofolate (TH4) catalyzed by?

Answer 24

dihydrofolate reductase

Question 25

essential amino acids

Answer 25

valine, leucine, isoleucine, tryoptophan, phenylalanine, histidine, methionine, threonine, lysine

Question 26

6 metabolic precursors

Answer 26

- aKG - pyruvate - 3-phosphoglycerate - oxaloacetate - phosphoenol pyruvate and erythrose 4-P - ribose 5-P

Question 27

Which amino acid(s) can be synthesized by the metabolic precursor a-KG

Answer 27

glutamate, glutamine, proline, arginine

Question 28

Which amino acid(s) can be synthesized by the metabolic precursor pyruvate

Answer 28

alanine, valine, leucine, isoleucine

Question 29

Which amino acid(s) can be synthesized by the metabolic precursor 3-phosphoglycerate

Answer 29

serine, glycine, cysteine

Question 30

Which amino acid(s) can be synthesized by the metabolic precursor phosphoenol pyruvate and erythrose 4-P

Answer 30

tryptophan, phenylalanine, tyrosine

Question 31

Which amino acid(s) can be synthesized by the metabolic precursor ribose 5-P

Answer 31

histidine

Question 32

conditionally essential amino acids

Answer 32

arginine, cysteine, glutamine, glycine, proline, tyrosine

Question 33

nonessential amino acids

Answer 33

alanine, asparagine, aspartate, glutamate, serine

Question 34

Which amino acid(s) can be synthesized by the metabolic precursor oxaloacetate

Answer 34

aspartate, asparagine, methionine, threonine, lysine

Question 35

4 types of feedback inhibition

Answer 35

- product inhibition - sequential - concerted - enzyme multiplicity

Question 36

regulation of synthesis of amino acids from oxaloacetate by feedback inhibition

Answer 36

- sequential - enzyme multiplicity - concerted inhibition