Answer: 9 kcal.
- A 4 kcal
- B 7 kcal
- C 9 kcal
- D 12 kcal
Correct answer: C. 9 kcal
Explanation: Fats provide 9 kcal per gram, which is more than double that of carbohydrates or proteins (both 4 kcal per gram).
As substrate concentration rises, reaction rate increases steeply at first, then plateaus at Vmax once every enzyme molecule is working at full capacity; Km is the substrate concentration giving half-maximal rate, and a LOWER Km means the enzyme reaches that rate with less substrate (higher affinity).
Concept context
Carbohydrates, proteins, lipids, nucleic acids, and enzyme kinetics. Essential foundation for understanding metabolism.