Answer: Size (smaller fragments travel farther).
- A Net electrical charge alone, since all DNA fragments carry identical mass
- B Absolute molecular mass alone, independent of fragment length or charge
- C Size (smaller fragments travel farther)
- D Specific nucleotide sequence composition recognized by the gel matrix
Correct answer: C. Size (smaller fragments travel farther)
Explanation: In agarose gel electrophoresis, all DNA fragments have the same charge-to-mass ratio, so separation is based on SIZE. Smaller fragments migrate through the gel pores faster and travel farther from the well.
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.