Why is glucose not a direct source of cellular energy?

What came first the elephent or the crocodile

When is your respiration rate likely to change? a. when your intestines are digesting b. when your cells have too much glucose c. when your cells need more oxygen d. when your liver is working after a meal

Aheterozygous normal male marries a woman with a sickle cell anemia. give the genotypes and possible phenotypes of the offspring