The journey of the Carbohydrates:-
I enter the Mouth, and The Teeth instantly greet us. We were warned about these. They’re there to crush us up, and give us a large surface area to prepare us for The Enzymes. And sure enough, right on time is Amylase, all ready to digest us. I suppose I should be honoured, I mean poor Amylase has travelled all the way from the Salivary Gland, just to digest us. Although, to be fair, Amylase did get a lift with the Saliva, who have come to lubricate us for The Great Swallowing. So far I’ve experienced all this with my brothers and sisters, who have been with me from the beginning, when the potato started growing in the field. But now, right in the midst of the madness, Amylase proceeds to pull us apart, and I slot easily into Amylase’s mouth. To my surprise I turn into sugar.
Now comes The Great Swallowing. It’s highly overrated, in my opinion. We tumble and slide down the Oesophagus on a sea of Saliva, and all of us are having a great time, enjoying our independence as Sugar. It’s all well and good until we land in the stomach with a splash into a pool of acid, which stings us incessantly, no matter which way we turn. As if this isn’t bad enough, great big slabs of muscle, which I can only assume are the walls of the stomach, move slowly inwards towards us and crush us once more. It brings back memories of the Mouth. After we’ve been turned and churned, what’s left of us slides down into the top of the Small Intestine, otherwise known as The Mighty Duodenum. We are given a warm welcome here by being squirted uncaringly with Bile, a nasty piece of work. It’s made in the liver, but is adopted by the Gall Bladder and lives there, out of everyone’s way. The Bile has a sudden change of heart and decides to be nice to us, by washing away that stinging acid which plagued us from the stomach. At this point, our good friend Amylase returns, with similar backup enzymes this time, and proceeds to finish us off entirely. We are then shoved over to Villi, an area of tissue that is full of creases and folds. Its large surface area maximises the effect of absorption, and we are easily absorbed into the bloodstream and carelessly spread around the body to cells, organs and various other parts. We start being absorbed in The Mighty Duodenum, the top of the Small Intestine, and the absorption process is not complete until we reach The Mighty Ileum at the other end of the Small Intestine.
The journey of the Proteins:-
As soon as I enter the Mouth, great big white grinding machines proceed to chew us up. We’re squished and crushed beyond all recognition, and by the time they stop we’re quite flat and much larger in area. The helpful Saliva soon arrives, and we are pulled with force down the Throat and into the Stomach as we’re subject to The Great Swallowing.
The second we reach the Stomach, millions upon millions of Protease begin attacking us cruelly. They’ve only come from the Stomach Lining, not far at all, and we slot easily into the mouths of the Protease, which were made for us. I thought the disintegration process took a while, but obviously not, because all too soon I find myself disintegrated into Amino Acids. At least one good thing has come of all this – I’ve lost all my bacteria! Woohoo! I’m finished on a high note in the small intestine, where I’m absorbed by the Villi into the blood. Active transport is used, and I move through cell membranes.
The journey of the Fats:-
Oh, the joys of being Fat. I’m eaten so much that I often make people fat. I am healthy in small amounts, honestly I am, but I can see you don’t believe me. But, if you eat too much of me, I will make you FAT! So, just think of what happens when you eat me…I’m shoved into your mouth, chewed furiously and swallowed quickly with barely a backward glance! You’ll be sorry for that. I slip down your oesophagus due to my greasy texture, and land gleefully in your stomach. This is when the fun begins.
I speed towards your duodenum, and on the way there I’m squirted with bile! Thanks for that. I swell and enlarge, getting bigger and bigger. I’m being emulsified. This is the worst part now. Lipase appears straight from the pancreas where it was created, and begins breaking me down, breaking me down slowly, slowly, until there’s barely anything left of the nutrient they once called Fat…now, in my place, are Fatty Acids and Glycerol. They are then diffused into the bloodstream, and if there are excessive amounts Active transport is used, and I move through cell membranes. From now on it is my job to make you look fat…that is unless you exercise frequently, thus turning me into energy. Please don’t do that.
Frances Duffy 10H1