Hi users of the internet! I’m Grace, an undergraduate from NUS Chemistry and this is my new blog. I will be sharing with you lovely people what I have done and experienced in a new module in NUS, which was created by a current Year 4 student. The module’s name is Chemistry of Food ((DMS1401CM) as seen from the blog web name) and as the name suggests, teaches us about the science behind how certain foodstuff are created. In case you didn’t know, the four basic food molecules are water, fats, carbohydrates and proteins, with the latter 3 being macro-nutrients found in food.

Water isn’t as simple as it seems; each molecule which is made up of an oxygen atom sandwiched between 2 hydrogen atoms and has a positive and negative end. This means that the molecule is polar. Furthermore, the molecule is not linear as the H-O-H bond angle is 104.5 degrees. This is due to oxygen exerting a stronger “force” which pulls the electrons shared between O and H to itself more. Water also clings strongly to itself due to the presence of hydrogen bonds. Water is also a neutral liquid with pH 7; this means that the concentration of H+ and OH- are the same and equal to 1 x 10^-7 Also, there are other ions in water other than H+ and OH-! They are metal ions such as Ca2+ and Mg2+ which also determines the ‘hardness’ of the water. More on water and its “hardness” would be covered in the next blog post on Coffee!

I also learnt about lipids which is commonly referred to as fats. Actually, lipids =/= fats; lipids are a diverse group of biomolecules whereas fats are a type of solid lipids and is usually found under the skin or around the organs. Fats can be classified as saturated or unsaturated fats. The difference between the 2 is that unsaturated fats have a  C=C bond present; the double bond opens up a space void of hydrogen atoms, thus allowing reactive molecules to attack and break up the fat. Hence, saturated fats are also more stable and takes a longer time to turn rancid than unsaturated fats. This is also why saturated fats are bad for the body as they are harder to break down. Who knew this module would aid me in selecting healthier food choices!

Next, I learnt about carbohydrates, the enemy of all dieters. The term “carbohydrates” comes from the early idea that they are made of water and carbon. Carbohydrates can be classified as monosaccharides, oligosaccharides and polysaccharides. Sugar and starch are 2 of the most commonly found forms of carbohydrates in food. They are our main form of energy as they are broken down into glucose which would enter the cells in our body. Unused glucose would be converted into glycogen and stored in the liver and muscles. However, over-consumption of carbohydrates would cause excess glycogen to be stored as fats for long-term energy storage.

Proteins are what I call the ‘bipolar major food molecules’ as they are the least stable. Unlike water, fats and carbohydrates which are pretty stable and staid, when exposed to a little heat, acid, salt or even air, the behavior of proteins change a lot. Proteins are not passive forms of stored energy, no they are what makes or breaks cells, they are at the heart of all organic activity, growth and movement. Proteins too are macromolecules, and are made up of building blocks called amino acids.

Unfortunately one blog post is not enough for me to discuss and praise the complexity of the basic molecules of food, but my next few blog posts would elaborate more on them and also incorporate my experiences in the food workshops. Stay tuned!