G1 Phase (Interphase) — Overview & Diagrams

First Gap Phase

When cells aren't dividing, they are spending their time preparing for the next division in a phase called interphase.

The first stage of this period is called G$_1$.

This phase is marked by cell growth. Not only does the cell get larger, but it also produces lots of organelles and proteins that it will need for DNA synthesis later on. This tends to be the longest phase of the cell cycle. Although it would make sense for the G in G$_1$ to stand for growth, it actually stands for gap.

At the end of G$_1$, the cell stops at a checkpoint. This checkpoint ensures that the cell has produced all of the necessary proteins, the cell is big enough, and the DNA is intact.

Before cell division, there is one more gap phase called G$_2$.

(Video) Interphase

by Patrick Haney

In this video, Patrick Haney discusses what cells do during interphase.

Summary

During G$_1$ phase, the cell increases its supply of proteins, creates its organelles, and grows larger. It also prepares for DNA replication in the next stage. Cells typically grow to about twice their normal volume in G$_1$. The duration of G$_1$ is highly variable even among cells of the same type. Time spent in G$_1$ is regulated by access to nutrients and materials necessary for increasing the size and protein content of a cell.

What's G$_1$ Phase?

The first gap stage (G$_1$) is the first step in interphase, hence the number $1$ in the name. It is the longest part of the cell cycle, so a cell spends most of its time in G$_1$.

This phase is all about growing bigger. The cell synthesizes new enzymes and molecules, physically increases in size, and stores nutrients for use during the later stages.

$$\color{#8925AE}{\text{Vocabulary Review:}}$$

$\color{#8925AE}{\text{Cell Cycle}}$ : The steps cells go through in order to grow and divide

$\color{#8925AE}{\text{Interphase}}$ : The longest part of the cell cycle where the cell grows and DNA is replicated to prepare for nuclear division

$\color{#8925AE}{\text{Nuclear Division}}$ : The process of dividing the nucleus