December 04, 2020, 11:39:16 AM
Forum Rules: Read This Before Posting


Topic: Catalytic activity  (Read 256 times)

0 Members and 1 Guest are viewing this topic.

Offline Alexei

  • Very New Member
  • *
  • Posts: 1
  • Mole Snacks: +0/-0
Catalytic activity
« on: November 01, 2020, 10:03:29 AM »
According to the definition, 1 enzyme unit is the amount of the enzyme that catalyzes the conversion of one micromole of substrate per minute under the specified conditions. But I'm having troubles understanding which unit is used to express the amount of enzyme.

Offline Borek

  • Mr. pH
  • Administrator
  • Deity Member
  • *
  • Posts: 26159
  • Mole Snacks: +1703/-402
  • Gender: Male
  • I am known to be occasionally wrong.
    • Chembuddy
Re: Catalytic activity
« Reply #1 on: November 01, 2020, 10:50:59 AM »
Doesn't matter. Enzyme unit refers to the enzyme activity, not amount.

You can express the amount of enzyme in solution using any concentration unit, but it won't tell you anything about its activity, which is what - most often - matters.
ChemBuddy chemical calculators - stoichiometry, pH, concentration, buffer preparation, titrations.info, pH-meter.info

Offline Babcock_Hall

  • Chemist
  • Sr. Member
  • *
  • Posts: 4414
  • Mole Snacks: +269/-18
Re: Catalytic activity
« Reply #2 on: November 04, 2020, 04:20:33 PM »
If one assumes that the enzyme is pure and fully active, then the number of units will be proportional to the mass of the enzyme.  The activity, expressed in units of enzyme, is an extensive property.  The specific activity (which I realize that you did not ask about) is an intensive property. Can you provide some context of your question?

Sponsored Links