Digestion By Enzymes

In this video we examine the process of digesting our food. We shall see how biological catalysts called enzymes break these food molecules apart and why they are necessary. Think of our food molecules as a train of trucks all coupled together. Digestion disconnects the trucks so we can re-assemble them in our own way. The breaking takes place by hydrolysis – a reaction where water is added and breaks the link. Let’s look at the simplified reaction for each of the foods we eat: Starch is a polymer of simple sugars which are joined by a glycosidic link C–O-C . When water is added the link breaks. Proteins are polymers of amino acids are joined in by the amide C-O-N-C link. Water breaks the chain into separate amino acids. The nucleotides in the DNA double helix are joined by phosphate groups. Water breaks the link. In the same way fats are hydrolysed into glycerol and fatty acid, such as stearic acid used in soap making! Water breaks the link Once our food is digested into monomers the molecules are small enough to get though the walls of our gut and into our blood ready to be used as fuel (sugars, fats and oils ) or to build up our own proteins and DNA.