🌯 Proteins (Edexcel)

Proteins are at the heart of living organisms. Their functions are very varied, from the hair on your head, to the haemoglobin in your red blood cells (which carries oxygen around the body), to the claws of a lion, to insulin (blood glucose regulation). All these highly varied proteins are made of their building blocks –Β amino acids. This is what the generalised structure of an amino acid looks like (make sure you canΒ drawΒ this):

If you’re wondering what this actually is, read on. The clues are in the name (as they usually are).
AMINOΒ – the H2N on the left hand side is an amino group
ACIDΒ – the COOH on the right hand side is a carboxylic acid group (simply an acid)
The hydrogen (H) on the bottom is there all the time (just like the amino group and the acid group), whileΒ the R groupΒ is the variable which determines what particular amino acid this will be. For example, if the R group was a hydrogen, the amino acid would beΒ glycine.
The next diagram showsΒ condensation, and the subsequent formation of a bond between two amino acids (any two). This bond is aΒ peptide bond. The resulting molecule is called a…