Putting bee honey on a cut kills bacteria. Honey contains a high concentration of sugar. Use your knowledge of water potential to suggest how putting honey on a cut kills bacteria. (AQA BIOL1)

Sugar is a solute and is able to dissolve in water. When sugar is dissolved in water, it has a low water potential. Water moves from a high water potential to a low water potential; from where there is a low concentration of sugar (i.e. the cut) to the high concentration of sugar (i.e. the honey). Thus pulling water out of the wound and out of the cells within the wound and creating a hypertonic environment. This also causes the bacterial cells to lose water (also via water potential gradient) causing cell damage and preventing normal cell function, thus, killing them.