Starch is a polymer or long string of sugar molecules, just as a protein is a long string of amino acids. Starch-containing plants are the universal staple foods. Fructose Glucose Stephen Jon Gislason MD Carbohydrates are energy and structural molecules produced by plants. Glucose is the key molecule in living systems and life is built around glucose and its related sugars.
Plant foods are essential to animal life and form the bulk of most human diets.
Currently rice, wheat, potatoes, yams, cassava, and corn are the world's most important staple foods. High-starch vegetables tend to be roots or tubers like potatoes, yams, turnips, winter squash, carrots, and beets. Yams and sweet potatoes are high-caloric root vegetables. The green leafy vegetables are more chemically diverse and interesting foods that supply less digestible carbohydrate but more vitamins, minerals, and non-digestible fiber. The seeds of 30 or so common legume species are important vegetables, since they are cheap, available and high in protein and fatty acids.