how are simple sugars used for energy compared to more complex sugars like the starch in pasta

Simple sugars and complex sugars like starch are both sources of energy for the body, but they differ in how quickly they are digested and how they affect blood glucose levels. Simple sugars, such as glucose and fructose, are made up of shorter chains or single sugar molecules. Because of their simple structure, they are digested quickly, leading to a rapid rise in blood glucose levels. This provides an immediate burst of energy as the sugar molecules enter the bloodstream swiftly and are taken up by cells for metabolism, primarily through glycolysis, the citric acid cycle, and oxidative phosphorylation to produce ATP, the cell's energy currency. In contrast, complex carbohydrates like starch found in pasta consist of longer chains of sugar molecules. They take longer to break down during digestion, which leads to a slower and more sustained release of glucose into the bloodstream. This slower digestion provides a more lasting and stable source of energy, avoiding the rapid spike and quick drop ("sugar crash") associated with simple sugars. Thus, simple sugars provide quick energy that is rapidly available but short- lived, whereas complex carbohydrates provide a more prolonged and steady energy supply due to their slower digestion and absorption.