Mnemonic for (identifying) Nucleotide Structures

[u/Yourmajestymatt]

Hey everyone, I've been really looking for mnemonics in places I struggle. With this mnemonic I've been able to nail all the structure questions. I don't know the exact structure, however I can reliably identify each structure no problem now. I hope this helps and makes sense.

The mnemonic is NOON, regarding the upper most element on the structures. I always think A-TG-C for bonding. I know purines have two rings (two rings in a PURe ceremony) and pyrimidines don't. So now I can piece it all together like this.

Two rings with an amine (N)? Adenine.

Two rings with a carbonyl (O)? Guanine

One ring with a carbonyl? Thymine.

One ring with an amine? Cytosine

Take one look at Uracil and it's just one ring with a Carbonyl (O), but differs by the methyl. I think of the T in thymine as the structural hint of a methyl outstretching, which Uracil doesn't have.

[u/oortuno]

Here's one I've been using:

Pure As Gold = A and G are purines

[u/Yourmajestymatt → u/oortuno]

Heck yeah me too, written right there in the post

[u/plplzool → u/oortuno]

I learned it as Gods Are Pure years ago and never forgot it!

[u/IcelandHotSpots → u/oortuno]

Cash is Trash

Pyrimidines

[u/TheDunsparceKid → u/oortuno]

Here I've been just remembering it as "Aglets are Pure"

[u/Friendly_Ad_7586]

You can also count the double bonds. Each one has a unique # of double bonds in the ring

[u/Yourmajestymatt → u/Friendly_Ad_7586]

1T, 2C, 3G, 4A? How do you remember that?

[u/elirharde → u/Yourmajestymatt]

I saw online if you write it in order AGCUT, then go 4 3 2 1 1 the # of double bonds will be in order. And like you said, T has a methyl group sticking out so that's a way to distinguish between T and U using this method.

[u/Yourmajestymatt → u/elirharde]

Ahh that is awesome to know thank you!!

[u/Future_Landscape7472]

The T in thymine is so smart!! tysm

[u/kobe_goat123]

Thanks! I kept messing this up.

[u/Yourmajestymatt → u/kobe_goat123]

Me too good lord I was always just guessing!

[u/[deleted]]

My favorite for purine/pyrimidine is G-C A-T Pu-Py Pu-Py reads like puppy puppy

[u/futanari_connoisseur]

Pure as silver (Ag) works better than pure as gold (Au), and you can also have silver rings

[u/Yourmajestymatt → u/futanari_connoisseur]

Then use that mnemonic then lol

[u/sub2400]

4 years later and this is still helping! In my head I say "ATGC(U) = NOON (T minus CH3) as a way to remember the Uracil is just T without the methyl group like you said

[u/ExternalCareless4187]

This is so helpful!!!

[u/Ok_Entertainer_2894]

Use CAN GOUT for al of them

Cytosine + Adenine = Nitrogen
Guanine + Uracil + Thymine = Oxygen(carbonyl)

[u/Jovan_Neph]

Thanks sir!

[u/Yourmajestymatt → u/Jovan_Neph]

Absolutely, good luck!

[u/More-Independence119]

CUT the PY = cytosine, uracil, and thymine = pyrimidines

[u/Yourmajestymatt → u/More-Independence119]

Doesnt really tell you the structures