Interphase Is Metabolically Active
- Interphase is often misunderstood as a "resting" phase, but it's actually a period of intense metabolic activity.
- The cell grows, replicates DNA, and prepares for division.
- Interphase occupies the majority of the cell cycle.
Interphase is not part of mitosis itself but is essential for ensuring the cell is ready to divide.
The Key Drivers Of Interphase
Cell size and mass doubles during interphase. For this growth to happen, it's dependent on the biosynthesis of cell components like proteins, DNA, and the growth and division of mitochondria and chloroplast.
- Protein Synthesis
- Ribosomes produce proteins needed for growth, DNA replication, and cell division.
- Enzymes like DNA polymerase are synthesized to facilitate DNA replication during S phase.
- Structural and regulatory proteins accumulate to support increased cell size.
- DNA Replication
- During S phase, the cell duplicates its DNA so each daughter cell receives an identical copy.
- Enzymes like helicase (unwinds DNA) and DNA polymerase (adds nucleotides) drive this process.
- DNA replication ensures genetic continuity. Without it, daughter cells would lack complete genetic instructions.
- Increase in Numbers of Mitochondria and Chloroplasts
- Mitochondria and chloroplasts increase in number through growth and division of existing organelles.
- These organelles cannot be synthesized from scratch, they must replicate from pre-existing ones.
- Both organelles contain their own DNA and divide independently through a process similar to binary fission.
Mitochondrial division is crucial because these organelles cannot be synthesized from scratch, they must be inherited from the parent cell.
Self reviewWhat are the three key enablers of growth during interphase?
