Glucose
Glucose is a simple sugar that cells use as their main source of energy.
Sugar cubes in a kitchen canister are your body's fuel supply. Each cube is one glucose molecule, a small, solid block of ready energy. When a cell needs power, it pulls a cube from the jar and burns it. The jar refills when you eat, and empties when you move.
Explaining glucose by grade level
When you add yeast to sugar water, the yeast wakes up and starts to eat. The sugar it likes best is glucose. As it eats, it makes gas that puffs up a bag. More glucose means more gas and a bigger bag.
Projects that explore glucose
Glucose is a simple sugar that cells use as their main source of energy. This project uses half a cup of sugar and yeast in a plastic bag. The yeast cells use that sugar for energy and release carbon dioxide gas.
Not all sugars have the same structure, and yeast is picky about which ones it can use for energy. You dissolve different carbohydrates in water, adjust the pH to 6.5, add yeast, and warm the mixture to 37.5 degrees Celsius. Glucose and sucrose — sugars with structures that yeast cells can easily break down — produce lots of gas. Others like galactose and lactose produce almost none.