Final answer:
The sugar found in germinating grains is maltose, which is formed by the partial hydrolysis of starch and glycogen. Maltose is often referred to as malt sugar and must be broken down by hydrolysis into monosaccharides before it can be absorbed by the human body.
Step-by-step explanation:
The sugar present in germinating grains is maltose. Maltose is a disaccharide that is produced by the partial hydrolysis of starch and glycogen during the germination process. Notably, in the brewing industry, malt (germinating barley) acts on starch to release maltose, which is why the sugar is commonly known as malt sugar. Maltose is approximately 30% as sweet as sucrose and cannot be metabolized directly by the human body because it is too large to pass through the intestinal cell membranes. Therefore, maltose must be broken down into its two monosaccharide units by the process of hydrolysis, a reaction typically catalyzed by the enzyme maltase within the body.