Cell Cycle - Interphase G₁

Description:

G₁ is also known as G₁ or Gap – I or Post-mitotic or Pre-synthetic phase or first growth phase. It is the phase between end of M-phase of previous cell cycle and initiation of DNA replication. Longest phase of interphase. RNA and proteins are synthesized. A large number of nucleotides, amino acids for histones synthesis and energy rich compounds are formed.

In G₁ phase a cell has three options −

• To continue cell cycle and enter S-phase.
• Stop cell cycle and enter G₀ phase.
• Get arrested in the G₁ phase whence it may enter G₀ phase or re-enter cell cycle.

The point at which the cell cycle is regulated or the check point is called G₁ cyclin or . Once G₁ check point is crossed then the cell cycle will go on uninterrupted till it is completed.