[khanar]

Here's a mnemonic to remind us of the heme synthesis steps

Ala placed in urine cup produces heme

Aminolevulinic Acid --> Porphobilinogen --> Uroporphyrinogen --> Coproporphyrinogen --> Protoporphyrin (Protoheme) ---> Heme

There are other intermediates in the long pathway but these are the most important ones to remember for the USMLE.

Note that the mnemonic also helps us remember that letting urine to stand in porphyria produces the classical red wine urine.

 

[khanar]

It could have been even more useful if you wrote something about the enzymes involved in these steps and what conditions we get with blocking of each step

 

[Sabio]

It could have been even more useful if you wrote something about the enzymes involved in these steps and what conditions we get with blocking of each step

Check this thread here
http://www.usmle-forums.com/usmle-step-1-bits-pieces/387-heme-synthesis-porphyria-diagram.html

 

[gc87]

mnemonic for Heme synthesis enzymes

Don't know if this helps, but here's something for remembering the enzymes in heme synthesis:
Some Doctors Prescribe Unlimited F(ph)enobarbitol (or fentanyl or any drug name that starts with F)
S = ala Synthase;
D = ala Dehydratase;
P = porphobilinogen deaminase;
U = Uroporphyrinogen decarboxylase;
F = Ferrochetalase.
I turned the PH in phenobarb to F so you can remember that phenobarb (or any of the barbiturates) affect heme synthesis (specifically precipitating an attack of AIP)
The S in ala Synthase can lead to Sideroblastic anemia (the two S's)

 

[bennyandthejets]

Heme Synthesis Intermediates

he Lies and Sucks. AL P.H.U.C.ing Punch Heme and make him pee blood (AIP- painful abdomen and port wine colored urine) and S.L.A.P him to Cry ( Porphyria cutanea tarda- photoSENSATIVE)

Enzymes
AL sinned, AL tried to Hide, but the poor demeans, he boxed forever inside
ALA synthase, ALA dehydratase, Porpho deaminase, Uroporph decarboxylase, Ferrochelatase

In order
1 Glycine and Succinyl CoA
2. ALA
3. Porphobilinogen
4. Hydroxymethylbilane
5. Uroporphyrinogen II
6. Coproporphyrinogen III
7. Proroporphyrin
8. Heme

Diseases in order
SLAP
1. Sideroblastic anemia (ALA Syn)
2. Lead poisoning (ALA deHYD)
3. Acute intermittent porphyria (Porpho deaminase)
4. Porphyria Cutanea Tarda (Uroporph decarBOXylase)
5. Lead poisoning ( Ferrochelatase)
Its late and Im tired, I must be pretty angry

 

[Garciarussell]

Here is a mnemonic for memorizing the deficient enzyme in Acute intermittent porphyria.

UPS brought Acute Intermittent Packages! )

UPS = Uroporphyrinogen Synthase (just assume S means synthase here)

(Be aware of the other names for UPS too! UPS = Hydroxymethylbilane synthase = Porphobilinogen Deaminase)

There is a figure on the forums that shows UPS as the enzyme, but they can use any of those names.

Here is one for Porphyria Cutanea Tarda:

"then they PiCT UP De Boxes" (PCT = porphyria cutanea tarda, UPD = Urophorphyrinogen decarboxylase) )

Here is one for the enzymes affected by lead poisoning:

"Lead sALAD Fork" (imagine an h near the D as a subscript) (ALADh = ALA Dehydratase, Fork = Ferrochelatase)

 

[rajeshsinghmd]

thanx

thanx,its really helpful

 

[KingJ]

Thank you so much!

 

[DocSteak]

Mnemonic collector

Thanks a bunch

 

[ttang94]

this is awesome. thanks.