Answer: Guanine.
- A Guanine
- B Cytosine and thymine
- C Thymine
- D Uracil
Correct answer: A. Guanine
Explanation: Adenine and guanine are the double-ringed purines; cytosine and thymine are the single-ringed pyrimidines.
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.