Bchm

Front 1

what do bacteria provide the host root system with?

Back 1

NH3 to be used in Gln synthesis

Front 2

what does the host provide the bacteria with?

Back 2

provides anaerobic bacteria with protection from O2 which is toxic to the nitrogenase components

Front 3

leghemoglobin

Back 3

an O2 binding protein produced by legumes that traps O2 before it can interact with the nitrogenase complex

Front 4

biologically, nitrogen fixing bacteria can reduce N2 to what?

Back 4

NH3

Front 5

Lightning fixes nitrogen by what?

Back 5

oxidizing it to nitrogen oxides which dissolve in water and eventually form nitrates

Front 6

nitrogen fixation is the process that coverts what?

Back 6

N2 from the gas form to a form useable by plants

Front 7

all nitrogen fixing species contain the nitroegnase complex which consists of what?

Back 7

1)nitrogenase: Fe-Mo protein-2Mo,30Fe; 4 polypeptides - 2alpha and 2beta (heterotetramer)
2)nitrogenase reductase: Fe protein- 8Fe, 2 identical polypeptides (homodimer)

Front 8

nitrogenase complex is aerobic or anaerobic?

Back 8

anaerobic

Front 9

electrons for nitrogen fixation are supplied by what?

Back 9

4NADH to form a reduced ferredoxin

Front 10

what is the biproduct of nitrogen fixation?

Back 10

H2

Front 11

what is the overall reaction of nitrogen fixation?

Back 11

N2 + 8 e- + 16 ATP + 12 H2O + 10 H+ goes to 2 NH4+ + 16 ADP + 16 Pi + H2

Front 12

what are the general essential AAs?What are the essential AAs for infants?

Back 12

Essential = isoleucine
leucine
lysine
methionine
phenylalanine
threonine
tryptophan
valine
Infants = arginine
histidine

Front 13

nonessential AAs are synthesized how?

Back 13

by incorporating ammonium ions into an alpha-keto acid

Front 14

why must essential AAs be supplied in the diet?

Back 14

b/c their precursors are not readily available - phenylpyruvate is not available to make phenyalanine

Front 15

prolonged protein deficiency leads to what?

Back 15

kwashiorkor which in children leads to growth failure and other problems

Front 16

what combines to form glutamate?

Back 16

alpha-ketoglutarate accepts ammonium ion (NADPH oxidized to NADP+)

Front 17

glutamate becomes glutamine with the addition of what?

Back 17

more ammonium ions and ATP

Front 18

transamination requires what?

Back 18

a specific aminotransferase enzyme and the coenzyme pyridoxal-5-phosphate (most useful form of vit. B6)

Front 19

glutamate and glutamine are the primary nitrogen donor molecules transferring what?

Back 19

the alpha-amino group of glutamate and the side chain amino group of glutamine to other molecules in a transamination reaction

Front 20

schiff base

Back 20

intermediate molecule that transamination occurs through, forms when a nitrogen atom adds to a carbonyl carbon
R-CH=N-R

Front 21

after the N of the AA adds to the C of the C=O and transfers an H to the O, a schiff base forms with what?

Back 21

the loss of water - resulting in a double bond between the N and C

Front 22

rearrangement of the double bond in the schiff base and addition of H2O forms what?

Back 22

an alpha-keto acid and the coenzyme-amino form - water completely removes the double bond freeing the alpha-keto acid

Front 23

how is alanine formed from the coenzyme-amino?

Back 23

pyruvate is added to the coenzyme-amino and water is removed forming a double bond between the N and carbonyl C of pyruvate. the double bond is then moved to the N and C of the coenzyme. H3O+ is added freeing alanine and regenerating the aldehyde coenzyme

Front 24

Serine AA Family

Back 24

glycine and cystein

Front 25

pyruvate AA family

Back 25

valine, alanine, leucine

Front 26

glutamate AA family

Back 26

glutamine, proline, arginine

Front 27

aspartate AA family

Back 27

asparagine, methionine, lysine, threonine to isoleucine

Front 28

aromatic AA family

Back 28

phosphoenolypyruvate + erythrose-4-P goes to phenylalanine, tyrosine, and tryptophan

Front 29

histidine AA family

Back 29

ribose-5-P goes to histidine ; shares common pathways with synthesis of nucleotides

Front 30

how is serine formed?

Back 30

1. 3P-glycerate is converted into 3-phosphohydroxy-pyruvate by dehydrogenase (NADH is formed)
2. 3-phosphohydroxy-pyruvate is converted into 3-phosphoserine by transaminase (glutamate is added and a-ketoglutarate is removed)
4. 3-phosphoserine is converted into serine by phosphatase (H2O is added and Pi removed)

Front 31

glycine is synthesized from serine by what?

Back 31

a one carbon transfer of the CH2OH carbon to THF

Front 32

what is tetrahydrofolate (THF)?

Back 32

a reduced form of folic acid and a frequently encountered one-carbon carrier

Front 33

what are the reactive parts of THF?

Back 33

nitrogens at positions 5 and 10

Front 34

what is needed to convert homocysteine to methionine?

Back 34

N5-methyl-THF and vit. B12 (cobalamin)

Front 35

Vit. B12 deficiency results in what?

Back 35

pernicious anemia; the disease can be caused by a missing stomach secretion needed to absorb the vitamin or by coeliac disease or tropical sprue; symptoms include low red blood cell count, neurological disorders

Front 36

What are the steps in cysteine synthesis?

Back 36

1. methionine is added to N5-methyl THF w/ addition of ATP
2. acceptor molecule removes methyl group leaving s-adenosyl homocysteine
3. H2O is added and adenosine is removed leaving homocysteine
4. serine is added and H2O is removed forming cystathionine by synthase
5. NH4+ and a-ketobutyrate are removed by gama-cystathionase forming CYSTEINE

Front 37

what is the structure of THF?

Back 37

Front 38

how is alanine formed from pyruvate?

Back 38

by the addition of glutamate and the removal of a-ketoglutarate

Front 39

proline is formed from what?

Back 39

glutamate- by the addition of 1 ATP and 2NADPH

Front 40

arginine forms from what?

Back 40

The urea cycle but you can't just take it out of the cycle - you have to add something first. So glutamate is converted to ornithine by the addition of Ac-SCoA and the removal of CoASH. By adding ornithine to the urea cycle you can extract arginine

Front 41

lysine forms from what?

Back 41

aspartate -
*by the addition of 1 ATP, reduction by 1 NADPH, and addition of pyruvate it forms the intermediate dihydropicolinate;
*forms the next intermediate diaminopimilate through NADPH reduction, addition of glutamate and removal of a-ketoglutarate,addition of succinyl CoA and removal of CoASH and succinate;
*in the final step lysine is formed by the addition of H+ and removal of CO2

Front 42

threonine is formed from what?

Back 42

aspartate - by the addition of 2ATP, reduction by 2NADPH, it forms the intermediate phosphohomoserine; addition of H2O and removal of Pi forms threonine

Front 43

methionine forms from what?

Back 43

aspartate - it is reduced by NADPH, ATP and cysteine are added, and pyruvate and NH4+ are removed leaving homocysteine; N5 methyl-THF is added and THF is removed leaving methionine

Front 44

the benzene ring is synthesized by what pathway?

Back 44

shikimate pathway - produces aromatics

Front 45

Phe or Trp are required for the synthesis of what?

Back 45

dopamine, epinephrine, and norepinephrine (part of the catecholamines);
Trp is required for synthesis of NAD(P) and the neurotransmitter serotonin