Wednesday, April 21, 2010

Digestion - nutrients

Heys People! I know I'm posting at such a late date, but at least I posted....right? Anyways, here is what I think is the summary of digestion. I've summarised the points I think is required for the exam, as well as adding in several other informations I think it would be fun to know, maybe. But anyways, here it is!

Digestion is basically just the breaking down of large, insoluble, indiffusible food substances into smaller, soluble, and diffusible food substances.

Easy to remember...right? Yeahs.

So anyways, there are 3 types of nutrients in total - carbohydrates, proteins, and fats.

Carbohydrates:

It provides energy for the body cells.

There are 3 types of carbohydrates, mainly the diasaccharides, monosaccharides, and the polysaccharides. I would not go into detail for that as you people have to study!!!

So anyways, there are 2 type of tests for carbohydrates, the Benedicts Test and the Iodine Test.

It is made up of Carbon, Hydrogen, and Oxygen (CHO)


Benedicts Test:

It tests for reducing sugar, and if reducing sugar is present, the solution would become reddish (is there even such a word?) -orange precipitate. If not, it would just remain as blue.

Iodine Test

It tests for, as you all should know, for starch. So, if starch is present, the solution would turn blue-black, or if starch is not present, then the solution would remain brown/yellow, depending on the colour of the iodine at first. But I guess it would be better if you choose brown instead, to you know, just to play safe XD

Protein:

It is the main substance used for the growth of new cells, and the repair of damaged cells. It also provides energy when the body lacks fats, or carbohydrates.

It is made up of Carbon, Hydrogen, Oxygen, and Nitrogen.

Protein can never never be stored as it is TOXIC!!!! Thus, it is removed by the body via egestion, as urea in urine.

Biuret's Test

The biuret test is used to test for the presence of protein. If protein is present, the solution would change to violet (yeah!!! 0_0). If not, it wouls remain as blue.