• Science & Mathematics >
  • Biology
  • Science & Mathematics >
  • Biology

In what ways do enzymes control the cell cycle?

  • Follow publicly
  • Follow privately
  • Unfollow
Best Answer
  • eli answered 5 years ago
Upon receiving a pro-mitotic extracellular signal, G1 cyclin-CDK complexes become active to prepare the cell for S phase, promoting the expression of transcription factors that in turn promote the expression of S cyclins and of enzymes required for DNA replication. The G1 cyclin-CDK complexes also promote the degradation of molecules that function as S phase inhibitors by targeting them for ubiquitination. Once a protein has been ubiquitinated, it is targeted for proteolytic degradation by the proteasome.

Active S cyclin-CDK complexes phosphorylate proteins that make up the pre-replication complexes assembled during G1 phase on DNA replication origins. The phosphorylation serves two purposes: to activate each already-assembled pre-replication complex, and to prevent new complexes from forming. This ensures that every portion of the cell's genome will be replicated once and only once. The reason for prevention of gaps in replication is fairly clear, because daughter cells that are missing all or part of crucial genes will die. However, for reasons related to gene copy number effects, possession of extra copies of certain genes would also prove deleterious to the daughter cells.


see wikipedia and utube "cell cycle"
  • 0
  • Comment

Other Answers (1)

  • Dre answered 5 years ago
    Enzymes are types of proteins that regulate cellular metabolism (chemical processes that occur within cells; like obtaining energy and controlling a cells activity) in many living organisms.


    I'm taking a biology college class
    • 0
    • Comment
  • In what ways do enzymes control the cell cycle?
    Sign In 

    to add your answer


Who is following this question?

    Member Since:
    Points: Points: Level
    Total Answers:
    Points this week: