DEGRADATION

Question 1

1 carbon moieits used for

Answer 1

Synehtesis of serine and methione
synthesis of TMP from dUMP
Synetheis of purine nucleotides

Question 2

what is THF used for

Answer 2

donor of 1 c moieties

Question 3

decsribe the structure of THF

Answer 3

positions N5 - N10 are sites where we can add carbon groupps. they can be in a number of oxidation states

• methy
• methylene
• formyl
• methenyl

Question 4

how does THF

Answer 4

it receives 1 c fragments from donors such as glycine, serine , histidine and transfers them to intermediates in the synthesis of purines, aa and TMP

Question 5

methotrexate

Answer 5

used to treat cancer, works by inhibiting DHFR

Question 6

aminopterin

Answer 6

an analog of folic acid, is an antineoplastic drug with immunosuppresive effcts used in chemotheray - competed with folate for DHFR

Question 7

SAM and its other name

Answer 7

is the source of methyl groups for many synthetic reactions , also known as active methione

Question 8

which reactions use SAM

Answer 8

synthesis of adrenaline from noradrenaline
synthesis of choline from ethanolamine
DNA methylation
phosphocreatine

Question 9

creatine phopshate

Answer 9

a storage form of high energy phosphate

the phopshate of ATP is transferred to creatine forming creatine phopshate

Question 10

creatine phosphate

Answer 10

a storage form of high energy phosphate

the phosphate of ATP is transferred to creatine forming creatine phosphate by creatine kinase. this reaction is reversable- so when energy demand is high cretaine phosphate donated a P to ADP to form ATP

both creatine and creatine phosphate are found in the brain, muscle and blood.

Question 11

location of creaine and creatine p

Answer 11

brain, muscle blood

Question 12

creatinine

Answer 12

formed int he muscle by the irreversible non ezymatic reaction of creatine phosphate, The amount of creatinine produced is related to
muscle mass and remains remarkably constant from
day to day. Creatinine is excreted by the kidneys and
the level of excretion (creatinine clearance rate) is a
measure of renal function

Question 13

creatine synthesis

Answer 13

glycine, arginine, methione
creating is made by 2 reactions

1. AA arginine and glycine form guanidoacetate in kindey
2. in liver guanoidocacetate gets methylated by SAM

Question 14

Methione

Answer 14

essential aa

2 pathways

1) activated methyl cyle
2)

Question 15

Methione

Answer 15

essential aa

2 pathways

1) activated methyl cylce
2) to produce succinyl coa which will allow to make ATP

Question 16

How does methion becaome a TCA intermediate

Answer 16

1. methione
2. propinoyl coa
3. methylmalonyl ca
4. succinyl co

Question 17

which 2 enzymes in the methione metabolism require B12

Answer 17

1. methione synthase

2. methylmaolonyl coa mutase

Question 18

How are SAM and THF linked

Answer 18

because when methione is made from homocytsteine ant the same time N5 methy THF gets converted to THF

Question 19

What is the central point of THF and why

Answer 19

n5 n10 thf because from it leads different routes

1. if we want dna synthesis (thymidylate synthases)
2. if we want to make methione/sam (methione synthase)
3. purine synthesis via n5 n10 methenyl THF

Question 20

which amino acids are essential

Answer 20

phenylalanine
methione
(come back)

Question 21

whats important for tyrosine

Answer 21

it makes catecholamines

Question 22

Alternative pathways
of phenylalanine
catabolism

Answer 22

The product of phenylalanine
transamination,
phenylpyruvate, is reduced
to phenyllactate or oxidized
to phenylacetate, and all 3
compounds appear in the
urine.
• The presence of
phenylacetate in the urine
gives a "mousy" odor.

Question 23

whats important for tyrosine

Answer 23

it makes catecholamines and melanin

Question 24

Hyperphenylalaninemia and

phenylketonuria (PKU)

Answer 24

both are defects in phenylalanine metabolism

PKU is a type of hyperphenylalaninemia- resulting from a mutation of the enzyme Gene

hyperphenylalaninemia- defect in the formation of cofactor BH4 or the BH4 reductase

main symptom of both is impaired cognitive development

accumulation of phenylalanine, which
becomes a major donor of amino groups in
aminotransferase activity and depletes
neural tissue of α-ketoglutarate.

therapy: low phenylalanine diet

Question 25

what things does tryptophan make

Answer 25

seratonin
niacin- precursor of NAD +NADP
indoleacetetate

Question 26

problems with tryptophan degradation

Answer 26

secondary pellegra if you dont eat food with tryptophan makes you deficient in vitamin B

Question 27

tryptophan degradation

Answer 27

Tryptophan is degraded to amphibolic intermediates via
the kynurenine-anthranilate pathway

to Alanine, (Pyruvate) and Acetoacetyl-CoA