Nutrition Science and Everyday Application - beta v 0.1

TYPES OF CARBOHYDRATES 179
The next figure shows an amylopectin segment containing 4 glucose units. The chemical
structure is represented differently, but can you spot the place where it branches?
Using our green hexagon to represent glucose, you can picture starch as something like
this:
Humans have digestive enzymes to break down both types of starch, which we’ll discuss
on the next page.
Starch is the storage form of carbohydrate in plants. Plants make starch in order to
store glucose. For example, starch is in seeds to give the seedling energy to sprout, and we
eat those seeds in the form of grains, legumes (soybeans, lentils, pinto and kidney beans,
for example), nuts, and seeds. Starch is also stored in roots and tubers to provide stored
energy for the plant to grow and reproduce, and we eat these in the form of potatoes, sweet
potatoes, carrots, beets, and turnips.
When we eat plant foods with starch, we can break it down into glucose to provide fuel
for our body’s cells. In addition, starch from whole plant foods comes packaged with other