Answer: Phosphate group.
- A Nitrogen base
- B Pentose sugar
- C Phosphate group
- D Hydrogen bond
Correct answer: C. Phosphate group
Explanation: A nucleoside is base + sugar only; adding one or more phosphate groups makes it a nucleotide.
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.