Interphase

Interphase is one of the phases of the cell cycle.  During this phase, the cell is preparing itself for division. The great majority of eukaryotic cells spend most of their lifetime in this stage (for example, most mature brain cells remain in interphase throughout their lives). Even though the cell is in the preparation for its division, the interphase is not a part of the mitosis/meiosis processes.

                This phase is constituted into three different stages. Each phase will only end after a "cellular checkpoint" checks for certain mistakes that can occur before letting the cell advance to the next stage, thus avoiding mutations and other malfunctions that could endanger the organism.

                G1 is the first stage. The cell grows to about the double of its former size. It synthesises a high amount of protein and organelles, which result in an increase of its cytoplasm's volume. If the cell's mechanisms "decide" that it should not divide itself, it enters G0 phase, remaining dormant in terms of division. Even though they do not divide themselves, they still continue to perform their main life functions.

                The second stage is called S (synthesis). Via semiconservative replication, the cell duplicates its DNA. When this stage is completed, all of the cell's chromosomes have two chromatids each, which means that they have two molecules of DNA per chromosome.

                After S, the cell goes into G2. In this phase, the cell continues to grow, preparing for division, which starts with prophase, implying that mitosis and cytokinesis are separate processes from interphase.

                                           1. Illustration of interphase and mitosis   

Alunos de Biologia Aplicada:

G11
Alice Loureiro

Cátia Mendes

Miguel Pacheco

Gustavo Pereira