Exam 2 Peng 3

Question 1

what factors make side chains different?

Answer 1

1) charge
2) length
3) aromatic rings
4) branched chain

Question 2

how do you deaminate aromatic rings?

Answer 2

strong enzymes and oxidation

Question 3

the 20 AA are converted to ___ intermediates products?

Answer 3

7 intermediate products, chemical rxn may convert one intermediate product to another

Question 4

intermediate products directly enter intermediary metabolism, resulting in either the synthesis of?

Answer 4

glucose of lipid or energy production

Question 5

what are he ketogenic amino acids?

Answer 5

leucine and lysine

Question 6

what are the glucogenic AND ketogenic AA?

Answer 6

isoleucine, tryptophan, phanylalanine, tyrosine

Question 7

what are the glucogenic AA?

Answer 7

everything except: leucine, lysine, isoleucine, typtophan, phenylalanine, tyrosine

Question 8

what is the entry point for 3 carbon AA? What are these AA?

Answer 8

pyruvate; alanine, cysteine, serine, glycine, threonine, tryptophan, asparate and asparagine

Question 9

what is the entry point for 5 carbon AA? examples?

Answer 9

alpha-ketoglutarate; glutaine, proline, arginine, histodine

Question 10

how are alanine, cysteine and serine converted to pyruvate?

Answer 10

by transamination, oxidative deamination and desulfuration

Question 11

tryptophan is catabolized to form?

Answer 11

alanine

Question 12

asparate and asparagine are converted to?

Answer 12

oxyloacetate (OAA)

Question 13

proline (oxidized) and glutamine (hydrolyzed) to form?

Answer 13

glutamate

Question 14

arginine is hydrolyzed to produce?

Answer 14

ornithine in the urea cycle and converted to glutamate

Question 15

**histidine converted to?

Answer 15

FlGlu

Question 16

what does FlGlu do?

Answer 16

denates formino group to tetragydrofolate (THF)

Question 17

THF is synthesized from?

Answer 17

folic acid

Question 18

folic acid deficiency? tested how?

Answer 18

increased excretion to FlGlu in urine, espesially after intake of histidine; test by checking urine for folic acid

Question 19

what all is converted to succinyl CoA?

Answer 19

methionine, valine, isoleucine, threonine

Question 20

how does methionine convert to succinyl CoA? what intermediate products?

Answer 20

through a complicated 9 step process, requires ATP

1) SAM
2) Homocysteine

Question 21

what is SAM? formed? activated methyl group in SAM transferred by?

Answer 21

S-adenosylmethionine

• formed when methionine condenses with adenosine triphosphate
• methyl transfered by methyltransferases to substrates

Question 22

the reaction to SAM to SAH is?

Answer 22

irreversible

Question 23

what is the importance of SAM?

Answer 23

MAJOR methyl donor

Question 24

what is homocystein?catalyzed by?

Answer 24

resynthesis of methionine

• remethylated to form methione
• catalyzed by methionine synthase

Question 25

homocystine reaction back to methionine is influenced by?

Answer 25

folic acid and B12

Question 26

where is the methyl group for homocysteine produced from?

Answer 26

5-methyl THF (tetrahydrofolate)

Question 27

what is THF? good carrier for what and why? carries where?

Answer 27

tetrahydrofolate is a good glycarbon carrier bc it has a pocket structurally to carry different types of carbons *carries units to methionine, nucleotide synthesis, and alternative synthesis of glycine and serine

Question 28

SAM and THF are both? difference is?

Answer 28

Both methyl transfer systems | *SAM can only transfer methyl group, THF can transfer many IC groups (aka with different oxidative states)

Question 29

what is SAH? hydrolized to?

Answer 29

S-adenosylhomocysteine | *hydrolyzed to homocysteine and adenosine

Question 30

elevatedlevels of SAH in plasma promotes?

Answer 30

oxydative damage, inflammation,andothelial dysfunction

Question 31

what reduced the levels of homocysteine in plasma?

Answer 31

B6, B12, and folic acid

Question 32

elevated levels of homocysteine are a marker for what diseases?

Answer 32

heart and cardiovascular diseases bc elevated levels lead to oxidative damage

Question 33

homocystinuria and cystathionine are treated how?

Answer 33

by B6 and B12 to reduce the elevated levels of homocysteine and vascular disease