A reducing sugar is one that reduce other compound and oxidized itself. A sugar can be called as reducing sugar if it has an aldehyde group in the open chain form or hemiacetal group in ring form.
The hemiacetal consists of a hydrogen bonded to a "R-group," an alcohol, an ether, and a carbon. When an aldehyde and an alcohol interact, the hemiacetal is created.
The chemistry of carbohydrates revolves around the interactions between hemiacetals and hemiketals. Carbohydrates are made up of long chains of the sugar units known as monosaccharides, much like proteins are long chains of amino acids and DNA and RNA are long chains of nucleotides.
It causes eutrophication which means that the algae have too much nutrients and take over the pond, use the oxygen so there is not enough left for marine life, which die as a result.
