What source is crucial for embryo growth in barley?

The correct answer focuses on the importance of broken down starch granules in embryo growth during the malting process of barley. As barley grains germinate, enzymes are activated that break down the stored starches within the grain into simpler sugars. These sugars serve as a vital energy source for the developing embryo.

During germination, the embryo relies on these easily accessible sugars for growth and development. The starch granules, when broken down, provide the necessary nutrients that support the process of growth and lead to the production of new plant tissue. This transformation plays a significant role in developing malt, which is essential for brewing.

Whole barley grains, while containing all necessary components for growth, do not provide the immediate energy source during the initial stages of germination. Whole grain proteins contribute to the overall nutritional content but are not directly metabolized for energy in the same way as sugars. Malting enzymes are involved in the breakdown of starches but are not a source themselves; rather, they facilitate the conversion of starches to sugars that can be utilized by the embryo.