Why are my bandages moving?

There's nothing quite as stomach-churning as a pile of maggots. I used to work with someone that was into fishing. He would buy a box of them and put it in the lab fridge. Once or twice the lid came off, and we were met with a squirming mess when we opened the door. That's not counting the time he forgot they were in there, and they turned into flies. 

We are naturally disgusted by some things because they spread diseases. Flies, vomit, puss, the list goes on. Would you be surprised if you went into a hospital and a doctor prescribed maggots to help heal a wound? That's right, maggots!  People with badly infected wounds can be prescribed maggots to help clean them. These particular maggots have been raised in sterile conditions, so please don't go rooting in the dustbin at home. 

How does this work? Warning you shouldn't read this before your tea! Maggots like to eat dead or rotting material. That’s precisely what is in some nasty wounds. These wounds can be infected or just not healing because the patient has poor circulation or diabetes. Sometimes these wounds don't respond to cleaning or antibiotics, so doctors must do something radical. This is where the marvellous medical maggots are brought in.  The maggots clean the wound by munching on all the rotting bits, The way they do this is disgusting. 

We digest our food inside our bodies. Our digestive system mixes what we've eaten with enzymes. Enzymes are chemicals that break down our food. They are made in our mouth, stomach, and small intestine. When they come into contact with our food, they break it down. This is called digestion. Each enzyme is specific to a particular food group.; proteas enzymes digest proteins, carbohydrase enzymes digest carbohydrates and lipase enzymes digest lipids (fats).

The way enzymes work is called the lock and key mechanism. Each enzyme has a unique shape called the active site. This active site matches the shape of the molecule that we want to break down. This molecule is called the substrate. The substrate locks into the enzyme like a key in a lock. When this happens, the substrate is broken down, producing substances our body can use.

The substrates in our digestive system are proteins, carbohydrates, and lipids. Each one needs a different enzyme because they have different shapes. In your mouth and small intestine, you have enzymes that digest starch, a carbohydrate; proteins are digested in your stomach and lipids are digested in your small intestine. All this occurs out of sight while you're going about your day.

Maggots use enzymes to digest their food, but they vomit them onto their lunch, wait for them to dissolve their food and then suck up the resulting liquid. This is why they don't get asked to parties very often. Their enzymes work just like ours, just outside their bodies. 

The advantage of using maggots to heal rotten wounds is that they are more precise than a surgeon removing the nasty bits and leaving the healthy tissue behind. Also, the chemicals they release into the wound kill bacteria, controlling any infection. This means they leave a nice clean wound that may start healing. As I said above, don't try this at home, these are special maggots produced for doctors to use, not the type that people go fishing with.