8: The Cell Cycle and Mitosis
- Page ID
- 173534
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)For most of this textbook, we have looked at each structure and process separately so that we can better understand them. We have focused on how the underlying chemistry of structures is essential to understanding the function of each organelle and each individual process. Here we are finally able to integrate all of the different bits of the cell and see how it all comes together as a whole and drives complex cellular processes. More specifically, we will be exploring the process of cell growth and division. We assume that this is not your first exposure to the concepts of cell growth and division (also known as mitosis and cytokinesis), and we approach the topic from that lens. If you need a refresher on the basics, we encourage you to return to the introduction and explore the review material.
Cell growth and division are moments within a larger process known as the cell cycle. The cell cycle impacts every aspect of cellular function. Every organelle gets involved in some way or another at every step of the way. Growth requires protein and membrane synthesis, energy production, transport of materials, and more. Selecting the correct moment to undergo cell division requires careful coordination of both the internal and external environment of the cell. Cells that divide at the wrong moment are unlikely to survive the process, so it must be carefully timed and controlled. Mitosis itself requires a complete and total disruption of cellular function as well as a complete but temporary rearrangement of the cell’s contents. This, too, requires precise coordination of the organelles. In this, the final chapter of this textbook, we will explore how the cell coordinates all of the various processes we’ve learned about so far in order to grow and then, at just the right moment, divide into two daughter cells.
- 8.1: Regulating the Cell Cycle- Checkpoint Control
- This page outlines the cell cycle's stages (G1, S, G2, M), crucial checkpoints (G1/S, G2/M), and regulatory proteins (cyclins, CDKs) that ensure proper cell division and DNA integrity. It highlights the importance of the G0 phase, polytene chromosomes, and the maturation promoting factor (MPF). Key regulators Wee1 and Cdc25 balance CDK activity, while p53 plays a role in DNA damage response.
- 8.2: Mitosis and Cell Division
- This page details the process of mitosis, highlighting the roles of the CDK-cyclin complex, cytoskeleton, and key proteins like condensin and cohesin in regulating cellular division. It explains the stages of mitosis, including prophase, metaphase, anaphase, and telophase, along with the mechanisms of chromatid separation and cytokinesis.
- 8.3: End-of-Chapter Material
- This page highlights the complexity of cellular systems in the cell cycle, focusing on the signaling for cell division timing, the cytoskeleton's role in mitosis, DNA packaging, and organelle distribution. It encourages appreciation for these interconnections in cell biology and includes review questions to enhance understanding of checkpoint control, CDKs, phosphorylation, and the differences in mitosis between plants and animals.
Thumbnail: In metaphase, the centrosomes have moved to the poles of the cell and have established the mitotic spindle. The chromosomes have congressed at the metaphase plate. (Public Domain; Roy van Heesbeen via Wikipedia)