AMINO ACID METABOLISM

Alanine

Arginine*

Asparagine

Aspartate

Cysteine

Glutamate

Glutamine

Glycine

Histidine*

Proline

Serine

Nonessential Glucogenic AA

Tyrosine

Threonine

Nonessential Glucoketogenic AA

Methionine

Threonine

Valine

Essential Glucogenic AA

Isoleucine

Phenylalanine

Tryptophan

Essential Glucoketogenic AA

Leucine

Essential Ketogenic AA

asparagine → aspartate

which AA forms oxaloacetate

asparaginase

emzyme that converts asparagine → aspartate then transamination

Asasparagine

if u have leukemia, what AA will become essential for the pt

asparaginase

what can be administered systemically to lower blood levels of Asn and deprive cancer cells of a required nutrient if a pt has a leukemia

a-ketoglutarate

what is the entry point for 5 Carbon amino acids glutamate, glutamine, proline. Also histidine and arginine (6 Carbons).

• glutamine —glutaminase→ glutamate → a-ketoglutarate

• proline —oxidized→ glutamate → a-ketoglutarate

• arginine -aginase→ ornithine (urea cycle) → a-ketoglutarate

• histidine -histidase→ uroconic acid →→ N- formiminoglutamate (FIGlu) → tetrahydrofolate → glutamate → a-ketoglutarate

AA that yields a-ketoglutarate

folate

if a pt lacks _______, pt can't convert N- formiminoglutamate (FiGlu) to Glutamate and excrete it in urine

methane*

methanol

formaldehyde

formic acid → carbonic acid

Some synthetic pathways require the addition of 1-carbon groups. These groups namely:

tetrahydrofolate (THF) or S- adenosyl methionine (SAM)

1-carbon unit —methane, methanol, formaldehyde, formic acid → carbonic acid require carries such as:

Folic acid (oxidized) → Dihydrofolate reductase (DHF) → Tetrahydrofolate (THF)

Folic acid formation

tetrahydrofolate; dihydrofolate reductase; 2 moles

what is the active form of folic acid and is is produced by?

how many moles of NADPH does it need?

N5 or N10

The 1-carbon unit is attached to either __ or __

alanine

cystine

serine

glycine

what are the AA that yields pyruvate

alanine (transaminated) → pyruvate

(pyruvate)

process of alanine

cystine (reduced) → cysteine —desulfuration→ pyruvate

(pyruvate)

process of cystine

• Serine → Glycine + N⁵,N¹⁰-methylene-THF

• Serine —serine dehydratase→ pyruvate

(pyruvate)

process of serine (2 fates)

• Glycine + N⁵,N¹⁰-methylene-THF → Serine

• Glycine → CO₂ + NH₄⁺ + N⁵,N¹⁰-methylene-THF

(pyruvate)

process of glycine (2 fates)

phenylalanine

tyrosine

AA that yields fumarate

phenylalanine —phenylalanine hydroxylase→ tyrosine

(fumarate)

process of phenylalanine

tyrosine → fumarate + acetoacetate

(fumarate)

process of tyrosine

glucogenic and ketogenic

(metabolic fate)

metabolic fate phenylalanine and tyrosine

phenylketonuria, alkaptonuria, albinism

What genetic disorders are associated with the phenylalanine → tyrosine degradation pathway?

Tetrahydrobiopterin (BH₄)

Which cofactor is required by phenylalanine hydroxylase to convert phenylalanine to tyrosine?

methionine

valine

isoleucine

threonine

AA that yields succinyl coA

(1) methionine -ATP→ S- adenosylmethionine (SAM) →S- adenosylhomocysteine (SAH) → homocysteine + serine → cystathionine → cysteine (vit B6)

(2) methionine -ATP→ S- adenosylmethionine (SAM) →S- adenosylhomocysteine (SAH) → homocysteine → reconverted to methionine

(succinyl coA)

pathway of methionine (2 fates)

choline → betaine aldehyde → betaine (also called trimethylglycine).

pathway of choline

betaine

In the liver, _______ can donate a methyl group to homocysteine to form methionine and dimethyl glycine. This allows the liver to have two routes for homocysteine conversion to methionine.

Threonine

_________ can also be degraded to pyruvate in other mammals but it appears not in humans

valine, isoleucine, threonine → propionyl coA → succinyl coA

(succinyl coA)

pathway of valine, isoleucine, threonine

leucine

isoleucine

lysine

tryotophan

AA that yields Acetyl CoA or Acetoacety| CoA

lysine → acetoacetyl coA

(acetoacetyl coA or acetoacetyl coA)

pathway of lysine

tryptophan → alanine + acetoacetyl coA

(acetoacetyl coA or acetoacetyl coA)

pathway of tryptophan

(acetoacetyl coA or acetyl coA)

pathway of leucine