National League for Nursing (NLN) Science Practice Exam

Carbohydrates and starches must be changed to what substance to be used by cells?

1. glucose

2. glycerin

3. sucrose

4. fructose

The correct answer is: glucose

Carbohydrates and starches are complex carbohydrates that the body cannot use directly in their original form. They must be broken down into simpler forms, particularly glucose, to be utilized effectively by cells for energy. The process of digestion involves enzymes that convert starches into glucose molecules. Once carbohydrates are reduced to glucose, they can enter the bloodstream and be transported to cells where they undergo cellular respiration to produce energy. Glucose is crucial as it serves as the primary energy source for the body's cells, particularly for neurons and red blood cells, which rely heavily on glucose for their metabolic needs. While other options may represent different types of sugars or compounds, they do not directly serve as the primary form of carbohydrate that cells can utilize for energy. This makes glucose the essential and correct answer for the question posed.