Life: What We’re Made of Part 2 (The Molecules)

I could have gone on to bigger things after the cell, but I thought it would be worth covering this bit first. I mentioned that the cells control molecules which in turn control atoms. I want to quickly explain what those molecules are.

There are several different types, but the three most prominent (if you ignore water) are:

  • Proteins.
  • Carbohydrates.
  • Fats

You might recognise them from the classroom, it’s probably more likely that you recognise them from the nutritional information on the back of whatever you’re eating.

So what do they each do.


Proteins are functional, they do things, they have jobs. Proteins are what make your hair and your skin, they can form antibodies and protect you from infections. Proteins can act as gateways moving things in and out of cells, or they can be transport molecules which move things from one side of the body to the other. They move your muscles and keep your brain thinking.

Proteins make us who we are and let us do what we want.

Fats (lipids):

Fats are largely structural. Remember the cell and that it’s covered by a Cell Membrane? That membrane is made of a special type of fat called a phospholipid. These guys are special because they are like magnets (they have a positive and negative side) when they are in water. One side of a phospholipid repels water, and the other is attracted to it.

Not my best sketch so far… But that is what a phospholipid looks like!

Anyway this ability allows phospholipids to join together (like magnets) and make a barrier between what is outside the cell and what is inside. You could say that because of this, a cell is made of fat, and as we’re all made up of cells: We’re all fat!

Some vitamins are also made from types of fat, giving them a more functional use.

Overall Fats keep the cell together, and therefore keep us together


This one is pretty simple, carbohydrates (or CHO’s) don’t actually do much at all. Their main purpose is to give us energy so that everything else can work. Most cells will store some CHO’s for immediate breakdown into energy and that’s about it. They do have some other uses (your blood group is determined by a CHO) but not many.

CHO’s as a result are what gives us energy to do what we do every day.

There are a few other things around as well (such as metals and ions) which are vitally important, but they don’t make up for a lot in comparison to these three.

So a quick summary:

  • We are largely made from proteins, fats and CHO’s.
  • Proteins perform functions and tasks.
  • Fats are for the most part structural and make up the Cell Membrane.
  • CHO’s are used for energy.

Leave a comment


  1. I read that research suggests a higher protein diet may prevent a number of diseases including osteoporosis, diabetes and heart disease. Do you think that’s true?

    • Firstly: I’m not a doctor. My opinion is not a medical one, and not one that should be taken as advice.

      My opinion: Osteoporosis is due to a problem with making bones (which although does involve proteins, is largely made up of mineral deposits, like calcium).

      Therefore personally I would say that proteins are most likely not the main cause. And dietary supplementation would probably have little effect. Most risk factors for osteoporosis are due to other factors, such as the menopause, which is obviously unavoidable for women.

      Diabetes is an autoimmune disorder in those who get it young (type 1). In those who get it at a later age it is a dietary problem (type 2), but not because of proteins, because of sugars (a form of carbohydrate).

      Type 1 is more or less incurable, apart from having a pancreatic transplant which won’t last more than a few years. I am almost certain that having a higher protein diet will do absolutely nothing to help it.

      Type 2, being a dietary problem may be helped by proteins in only one foreseeable way: It makes you cut down on high GI carbohydrates, lowering the risk factor for diabetes type 2. But this again is not because of a high protein diet, but instead because of a lower carb diet.

      Heart disease is more of the same. Risk factors include age, fatty diets, diabetes and a lot of other things. A high protein diet would do little to help.

      But there is always a chance! Placebo’s work right? If you believe in it, it will have some effect, however small.

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