Fairytales and Biology III

So many thanks to Mary and Rosella for your suggestions. I shall be sure to write a few more poems now based on your ideas. A little teaser- the fourth poem is tenetatively titled Adenine and Uracil- A Molecular Beanstalk/ Jack and The Giant- A Tale of DNA Replication/ Fee Fi Fo Fum- The Role of DNA Halicase
Which one of the three do you like best?
But as promised I bring you "Little Red Riding Hood and Cholera" I hope you enjoy.

There once was a girl in a cloak of red
And a silken hood with which to cover her head
A basket of delicacies hung by her side
As into the woods did Red Riding Hood stride

The reason for this was her twice monthly visit
To call in on grandma, a lady exqusite
A wrinkled old woman- with a bright kindly face
And wearing a bonnet of finest white lace

Yet whilst she was walking she happened to find
An intelligent lifeform of the nastier kind
For who wouldn't suspect her of utter delerium?
When she claimed to have talked to a cholera bacterium

But one that was almost the size of a bear
With a flagellum the length of a dining room chair
And a coating or capsule of mucilaginous slime
A creature commited to heinous crime

For the cholera cell who was called Vibrio
Full name Vibrio cholerae I happen to know
Would sneak up on his victim and unleash a protein
Both toxic and specialised to the small intestine

So Vibrio inquired of Red Riding Hood
Where was she going alone in the wood?
And the little girl pointed "Just over that hill
To vist my grandma whose feeling quite ill"

And Vibrio cholerae made a suggestion
You're not bringing flowers? That's out of the question!
For every invalid is cheered up with flowers!
Just pick some to bring her. It won't take you hours.

And off ran the cholera.
Red faced and rosy
Whilst Red Riding Hood gathered
A sweet smelling posy

And when she arrived at her grandma's abode
She took off her hood and set down her load.
But grandma looked different all tucked up in bed.
Whilst the white lacy bonnet looked small on her head.

And Red Riding Hood inquired with out further delay
Grandma how circular is your DNA!
And  grandma just smiled and mumbled and sighed
"All the better to evolve with!" she quickly replied.

But grandma! What a number of plasmids you have!
Pray! Why do you have them? Just what is their function?
"Oh they possess different genes I can add or remove
To my circular DNA, they work in conjunction

For simple DNA of the circular fashion
Is better than the chromosomes you praise with a passion
For I can change its structure at will on the slighest suspicion
That the environment will undergo an adverse condition

Yet grandma your ribsosomes are tiny and small
I barely can tell if you have them at all!
At this grandma flushed and was rumoured to announce
It's not the size that matters, it's what you do with it that counts!

And suddenly grandma transformed before her eyes
It was really Vibrio all along in cunning disguise
And he pounced upon Red Reding Hood and said with a sneer
"All the better to give you diarrhoea!"

And the toxin punched a hole in her epithelial cell
And Little Red Riding Hood didn't feel well
For whilst the cholera laughed from his podium
Into her intestine poured ions of sodium

Which happens to be
Severly detrimental
To the small intestine's
Water potential

And so water by osmosis moves
Into the intestine which the body removes
And thus Red Riding Hood's greatest fear
Dehydration through diarrhoea

Yet a passing lumberjack
Searching for his daughter
Saved the day
With a glass of water

Which he threw at the cholera
It acted like acid
You could tell that it worked
When his flagellum went flaccid

And though the cholera had melted away
The lumberjack looked on with a look of dismay
For there on the floor was the lumberjack's daughter
Killed by the cholera he happened to slaughter

But the lumberjack was filled with determination
And remembered a cure- oral rehydration
So he boiled some water and added some salt
Some sugar, a lemon and a wee dash of malt

And as the first drops passed Red Riding Hood's lips
She sat up and eagerly took a few sips
And thus ends our tale with Red Riding Hood revivied
And the outbreak of cholera never arrived