Nutrition Science and Everyday Application - beta v 0.1

TYPES OF CARBOHYDRATES 175
1 – Glucose
Here’s the chemical structure of glucose:
In this class, we’ll sometimes use a simpler green hexagon to represent glucose:
You’re already familiar with glucose, because it’s the main product of photosynthesis.
Plants make glucose as a way of storing the sun’s energy in a form that it can use for growth
and reproduction.
In humans, glucose is one of the most important nutrients for fueling the body. It’s
especially important for the brain and nervous system, which aren’t very good at using
other fuel sources. Muscles, on the other hand, can use fat as an energy source. (In practice,
your muscles are usually using some combination of fat and glucose for energy, which we’ll
learn more about later.)
Food sources of glucose: Glucose is found in fruits and vegetables, as well as honey, corn
syrup, and high fructose corn syrup. (All plants make glucose, but much of the glucose is
used to make starch, fiber, and other nutrients. The foods listed here have glucose in its
monosaccharide form.)
2 – Fructose
Here’s the chemical structure of fructose:
In this class, we’ll sometimes use a simpler purple pentagon to represent fructose:
Fructose is special because it is the sweetest carbohydrate. Plants make a lot of fructose
as a way of attracting insects and animals, which help plants to reproduce. For
example, plants make nectar, which is high in fructose and very sweet, to attract insects that
will pollinate it. Plants also put fructose into fruit to make it tastier. Animals eat the fruit,