Cell biology (also called cellular biology or formerly cytology, from the Greek kytos, "container") is an academic discipline that studies cells. This includes their physiological properties, their structure, the organelles they contain, interactions with their environment, their life cycle, division and death. This is done both on a microscopic and molecular level. Cell biology research extends to both the great diversity of single-celled organisms like bacteria and the many specialized cells in multicellular organisms like humans. Image File history File links This is a lossless scalable vector image. ... Contents   Overviews   Academia   Topics   Basic topics   Glossaries   Portals   Categories // This is a list of academic disciplines. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the... This article or section does not cite any references or sources. ... In cell biology, an organelle is one of several structures with specialized functions, suspended in the cytoplasm of a eukaryotic cell. ... The cell cycle, or cell-division cycle, is the series of events that take place in a eukaryotic cell leading to its replication. ... This does not adequately cite its references or sources. ... A section of mouse liver showing an apoptotic cell indicated by an arrow Apoptosis (pronounced apo tō sis) is a process of suicide by a cell in a multicellular organism. ... Robert Hookes microscope (1665) - an engineered device used to study living systems. ... 3D (left and center) and 2D (right) representations of the terpenoid molecule atisane. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell being used to describe the smallest unit of a living organism Cells in culture, stained for keratin (red) and DNA (green) The cell is the... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... In biology and ecology, an organism (in Greek organon = instrument) is a living being. ... This article is about modern humans. ...

Knowing the composition of cells and how cells work is fundamental to all of the biological sciences. Appreciating the similarities and differences between cell types is particularly important to the fields of cell and molecular biology. These fundamental similarities and differences provide a unifying theme, allowing the principles learned from studying one cell type to be extrapolated and generalized to other cell types. Research in cell biology is closely related to genetics, biochemistry, molecular biology and developmental biology. Biology studies the variety of life (clockwise from top-left) E. coli, tree fern, gazelle, Goliath beetle Biology (from Greek: βίος, bio, life; and λόγος, logos, knowledge), also referred to as the biological sciences, is the study of living organisms utilizing the scientific method. ... Molecular biology is the study of biology at a molecular level. ... The term moral obligation has a number of meanings in moral philosophy, in religion, and in laymans terms. ... This article is about the general scientific term. ... Biochemistry is the study of the chemical processes in living organisms. ... Molecular biology is the study of biology at a molecular level. ... Views of a Foetus in the Womb, Leonardo da Vinci, ca. ...

Understanding cells in terms of their molecular components.

Image File history File links NIEHScell. ... Image File history File links NIEHScell. ...

Processes

Movement of proteins

Proteins (red and green stain) at different locations in a cell.

Every cell typically contains hundreds of different kinds of macromolecules that function together to generate the behavior of the cell. Each type of protein is usually sent to a particular part of the cell. An important part of cell biology is the investigation of molecular mechanisms by which proteins are moved to different places inside cells or secreted from cells. Image File history File links FluorescentCells. ... Image File history File links FluorescentCells. ... Illustration of a polypeptide macromolecule Structure of a polyphenylene dendrimer macromolecule reported by Müllen and coworkers in Chem. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ...

Most proteins are synthesized by ribosomes in the cytoplasm. This process is also known as protein biosynthesis or simply protein translation. Some proteins, such as those to be incorporated in membranes membrane proteins, are transported into the ER or endoplasmic reticulum during synthesis and further processed in the Golgi apparatus. From the Golgi, membrane proteins can move to the plasma membrane, to other subcellular compartments or they can be secreted from the cell. The ER and Golgi can be thought of as the "membrane protein synthesis compartment" and the "membrane protein processing compartment", respectively. There is a semi-constant flux of proteins through these compartments. ER and Golgi-resident proteins associate with other proteins but remain in their respective compartments. Other proteins "flow" through the ER and Golgi to the plasma membrane. Motor proteins transport membrane protein-containing vesicles along cytoskeletal tracks to distant parts of cells such as axon terminals. A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... Figure 1: Ribosome structure indicating small subunit (A) and large subunit (B). ... Organelles. ... An overview of protein synthesis. ... Translation is the second process of protein biosynthesis (part of the overall process of gene expression). ... A membrane protein is a protein molecule that is attached to, or associated with the membrane of a cell or an organelle. ... The endoplasmic reticulum or ER is an organelle found in all eukaryotic cells that is an interconnected network of tubules, vesicles and cisternae that is responsible for several specialized functions: Protein translation, folding, and transport of proteins to be used in the cell membrane (e. ... Micrograph of Golgi apparatus, visible as a stack of semicircular black rings near the bottom. ... Drawing of a cell membrane A component of every biological cell, the cell membrane (or plasma membrane) is a thin and structured bilayer of phospholipid and protein molecules that envelopes the cell. ... The kinesin dimer attaches to, and moves along, microtubules. ... The eukaryotic cytoskeleton. ... An axon or nerve fiber, is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neurons cell body or soma. ...

Some proteins that are made in the cytoplasm contain structural features that target them for transport into mitochondria or the nucleus. Some mitochondrial proteins are made inside mitochondria and are coded for by mitochondrial DNA. In plants, chloroplasts also make some cell proteins. A nuclear localizing sequence (NLS) is an amino acid sequence which acts like a tag on the exposed surface of a protein. ... In cell biology, a mitochondrion is an organelle found in the cells of most eukaryotes. ... In cell biology, the nucleus is an organelle, found in most eukaryotic cells, which contains most of the cells genetic material. ... Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis. ...

Extracellular and cell surface proteins destined to be degraded can move back into intracellular compartments upon being incorporated into endocytosed vesicles. Some of these vesicles fuse with lysosomes where the proteins are broken down to their individual amino acids. The degradation of some membrane proteins begins while still at the cell surface when they are cleaved by secretases. Proteins that function in the cytoplasm are often degraded by proteasomes. Clathrin is a protein that is the major constituent of the coat of the coated pits and coated vesicles formed during endocytosis of materials at the surface of cells. ... Various organelles labeled. ... Phenylalanine is one of the standard amino acids. ... Secretases are enzymes that snip pieces off a longer protein that is embedded in the cell membrane. ... A proteasome is a barrel-shaped multi-protein complex that can digest other proteins into short polypeptides and amino acids in an ATP-driven reaction. ...

Other cellular processes

• Cell division - The origin of new cells.
• Cell signaling - Regulation of cell behavior by signals from outside.
• Active transport and Passive transport - Movement of molecules into and out of cells.
• Adhesion - Holding together cells and tissues.
• Transcription and mRNA splicing - gene expression.
• Cell movement: Chemotaxis, Contraction, cilia and flagella
• DNA repair and Cell death
• Metabolism: Glycolysis, respiration, Photosynthesis
• Autophagy - The process whereby cells "eat" their own internal components or microbial invaders.

This does not adequately cite its references or sources. ... Cell signaling is part of a complex system of communication that governs basic cellular activities and coordinates cell actions. ... Sodium-Potassium pump, an example of Primary active transport secondary active transport Active transport (sometimes called active uptake) is the mediated transport of biochemicals, and other atomic/molecular substances, across membranes. ... Passive transport bobo means of moving biochemicals, and other atomic or molecular substances, across membranes. ... Schematic of cell adhesion The study of cell adhesion is part of cell biology. ... A micrograph of ongoing gene transcription of ribosomal RNA illustrating the growing primary transcripts. ... In genetics, splicing is a modification of genetic information after transcription, in which introns of precursor messenger RNA (pre-mRNA) are removed and exons of it are joined. ... Chemotaxis is a kind of taxis, in which bodily cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment. ... A top-down view of skeletal muscle A muscle contraction (also known as a muscle twitch or simply twitch) occurs when a muscle fiber generates tension through the action of actin and myosin cross-bridge cycling. ... cross-section of two cilia, showing 9+2 structure A cilium (plural cilia) is a fine projection from a eukaryotic cell that constantly beats in one direction. ... For the insect anatomical structure, see Antenna (biology). ... DNA damage resulting in multiple broken chromosomes DNA repair refers to a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. ... Programmed cell death (PCD) is the deliberate suicide of an unwanted cell in a multicellular organism. ... Structure of the coenzyme adenosine triphosphate, a central intermediate in energy metabolism. ... The word glycolysis is derived from Greek γλυκύς (sweet) and λύσις (rupture). ... Cellular respiration was discovered by mad scientist Mr. ... The leaf is the primary site of photosynthesis in plants. ... Autophagy is also a synonym for self-cannibalism Autophagy, or ocytosis, is a process of sequestering organelles and long-lived proteins in a double-membrane vesicle inside the cell, where the contents are subsequently delivered to the lysosome for degradation. ...

Techniques

• Microscopy and Immunostaining
• Gene knockdown and Transfection
• Cell culture and Radioactive tracers
• PCR and In situ hybridization
• DNA microarray screens of gene expression
• Computational genomics approaches are used to find patterns in genomic information ^[1]

Image of oogenesis in Drosophila melanogaster Source: my personal image. ... Image of oogenesis in Drosophila melanogaster Source: my personal image. ... Microscopy is any technique for producing visible images of structures or details too small to otherwise be seen by the human eye, using a microscope or other magnification tool. ... Immunostaining is a general term in biochemistry that applies to any use of an antibody-based method to detect a specific protein in a sample. ... A gene knockdown is either a genetically modified organism that carries one or more genes in its chromosomes that has been made less active or had its expression reduced or is the use of a reagent such as an antisense oligo to decrease expression of a specific gene, copying the... Transfection describes the introduction of foreign material into eukaryotic cells. ... Epithelial cells in culture, stained for keratin (red) and DNA (green) Cell culture is the process by which either prokaryotic or eukaryotic cells are grown under controlled conditions. ... A radioactive tracer is a substance containing a radioactive isotope (radioisotope). ... Wikipedia does not yet have an article with this exact name. ... In situ hybridization (ISH) is a type of hybridization that uses a labeled complementary DNA or RNA strand (i. ... It has been suggested that Gene chip technology be merged into this article or section. ... Modern genomics has been deined in many ways: * The study of genomes. ...

Purification of cells and their parts

Purification of cells and their parts is achieved in the following ways:

• Flow cytometry
• Cell fractionation
  • Release of cellular organelles by disruption of cells.
  • Separation of different organelles by centrifugation.
• Proteins extracted from cell membranes by detergents and salts or other kinds of chemicals.
• Immunoprecipitation.

Analysis of a marine sample of photosynthetic picoplankton by flow cytometry showing three different populations (Prochlorococcus, Synechococcus and picoeukaryotes) Flow cytometry is a technique for counting, examining and sorting microscopic particles suspended in a stream of fluid. ... Cell fractionation is the separation of homogeneous sets from a heterogeneous population of cells Steps Disruption of cells and liberation of organelles. ... Centrifugation is a process that involves the use of the centrifugal force for the separation of mixtures. ... Look up cell membrane in Wiktionary, the free dictionary. ... Laundry detergents are just one of many possible uses for detergents Detergent is a compound, or a mixture of compounds, intended to assist cleaning. ... For other uses, see Salt (disambiguation). ... Immunoprecipitation is the technique of precipitating an antigen out of solution using an antibody specific to that antigen. ...

Some structures inside cells

Electronmicrograph.

• Organelle - term used for major subcellular structures
• Chloroplast - key organelle for photosynthesis
• Cilia - motile microtubule-containing structures of eukaryotes
• Cytoplasm - contents of the main fluid-filled space inside cells
• Cytoskeleton - protein filaments inside cells
• Ribosome - RNA and protein complex required for protein synthesis in cells
• Endoplasmic reticulum - major site of membrane protein synthesis
• Flagella - motile structures of bacteria, archaea and eukaryotes
• Golgi apparatus - site of protein glycosylation in the endomembrane system
• Membrane lipid and protein barrier
• Lipid bilayer - fundamental organizational structure of cell membranes
• Vesicle - small membrane-bounded spheres inside cells
• Mitochondrion - major energy-producing organelle
• Nucleus - holds most of the DNA of eukaryotic cells

Image File history File links Electronmicroscopynhlbi. ... Image File history File links Electronmicroscopynhlbi. ... Schematic of typical animal cell, showing subcellular components. ... Chloroplasts are organelles found in plant cells and eukaryotic algae that conduct photosynthesis. ... Schematic of typical animal cell, showing subcellular components. ... The leaf is the primary site of photosynthesis in plants. ... cross-section of two cilia, showing 9+2 structure A cilium (plural cilia) is a fine projection from a eukaryotic cell that constantly beats in one direction. ... Microtubules are one of the components of the cytoskeleton. ... Kingdoms Animalia - Animals Fungi Plantae - Plants Chromalveolata Protista Alternative phylogeny Unikonta Opisthokonta Metazoa Choanozoa Eumycota Amoebozoa Bikonta Apusozoa Cabozoa Rhizaria Excavata Corticata Archaeplastida Chromalveolata Animals, plants, fungi, and protists are eukaryotes (IPA: ), organisms whose cells are organized into complex structures by internal membranes and a cytoskeleton. ... Organelles. ... The eukaryotic cytoskeleton. ... Figure 1: Ribosome structure indicating small subunit (A) and large subunit (B). ... Ribonucleic acid or RNA is a nucleic acid polymer consisting of nucleotide monomers that plays several important roles in the processes that translate genetic information from deoxyribonucleic acid (DNA) into protein products; RNA acts as a messenger between DNA and the protein synthesis complexes known as ribosomes, forms vital portions... The endoplasmic reticulum or ER is an organelle found in all eukaryotic cells that is an interconnected network of tubules, vesicles and cisternae that is responsible for several specialized functions: Protein translation, folding, and transport of proteins to be used in the cell membrane (e. ... Protein synthesis is the creation of proteins using DNA and RNA. Biological and artificial methods for creation of proteins differ significantly. ... A flagellum (plural, flagella) is a whip-like organelle that many unicellular organisms, and some multicellular ones, use to move about. ... Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ... Phyla Crenarchaeota Euryarchaeota Korarchaeota Nanoarchaeota ARMAN The Archaea (), or archaebacteria, are a major group of microorganisms. ... Micrograph of Golgi apparatus, visible as a stack of semicircular black rings near the bottom. ... Glycosylation is the process or result of addition of saccharides to proteins and lipids. ... It has been suggested that Endomembrane System be merged into this article or section. ... Look up cell membrane in Wiktionary, the free dictionary. ... Some common lipids. ... A representation of the 3D structure of myoglobin, showing coloured alpha helices. ... This fluid lipid bilayer cross section is made up entirely of phosphatidyl choline. ... Look up cell membrane in Wiktionary, the free dictionary. ... In cell biology, a vesicle is a relatively small and enclosed compartment, separated from the cytosol by at least one lipid bilayer. ... Electron micrograph of a mitochondrion showing its mitochondrial matrix and membranes In cell biology, a mitochondrion (plural mitochondria) is a membrane-enclosed organelle that is found in most eukaryotic cells. ... HeLa cells stained for DNA with the Blue Hoechst dye. ... The structure of part of a DNA double helix Deoxyribonucleic acid, or DNA, is a nucleic acid molecule that contains the genetic instructions used in the development and functioning of all known living organisms. ...

See also

• Cell disruption
• [[List of publications in biol

.hrtrthhthrrthwtwrogy#Cell biology|Important publications in cell biology]] Cell disruption is a method or process for releasing biological molecules from inside a cell. ...

• Institute of Molecular and Cell Biology
• The American Society for Cell Biology

The Institute of Molecular and Cell Biology (IMCB) is an autonomous research institute of the Agency for Science, Technology and Research in Singapore. ... The American Society for Cell Biology (ASCB) is a non-profit organization whose purpose is to promote and develop the field of cell biology. ...

Notable cell biologists

George Emil Palade

• Robert Hooke
• Anton van Leeuwenhoek
• Günter Blobel
• Marc Kirschner
• Peter Agre
• Keith R. Porter
• Ira Mellman
• Paul Nurse
• H. Robert Horvitz
• Christian de Duve
• Edmund Beecher Wilson
• Peter D. Mitchell
• Michael Swann
• George Emil Palade
• Geoffrey M. Cooper

George Emil Palade Portrait public domain File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... George Emil Palade Portrait public domain File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ... Dr. Palade won the Nobel Prize in 1974. ... Robert Hooke, FRS (July 18, 1635 – March 3, 1703) was an English polymath who played an important role in the scientific revolution, through both experimental and theoretical work. ... Anton van Leeuwenhoek Anton van Leeuwenhoek (October 24, 1632 - August 30, 1723, full name Thonius Philips van Leeuwenhoek (pronounced Layewenhook) was a Dutch tradesman and scientist from Delft, Netherlands. ... Günter Blobel (born May 21, 1936) is a German biologist. ... Professor Marc W. Kirschner is an American systems biologist. ... Peter Agre (born January 30, 1949) is an American biologist who was awarded the 2003 Nobel Prize in Chemistry (which he shared with Roderick MacKinnon) for his discovery of aquaporins. ... KeithPorter (1912-1997) was an American cell biologist. ... Ira Mellman, Ph. ... Sir Paul M. Nurse, FRS, (b. ... H. Robert Horvitz is an American biologist best known for his research on the nematode worm Caenorhabditis elegans. ... Christian de Duve (born October 2, 1917) is a biochemist. ... Edmund Beecher Wilson (1856 - 1939) was an American geneticist and zoologist. ... Peter Dennis Mitchell (September 29, 1920–April 10, 1992)[1] was a British biochemist who was awarded the 1978 Nobel Prize for Chemistry for his discovery of the chemiosmotic mechanism of ATP synthesis. ... Ennobled as Lord Swann of Coln St Denys, Michael Meredith Swann FRS (1920-1990) was a distinguished molecular and cell biologist working on the mechanisms of cell division and fertilisation. ... Dr. Palade won the Nobel Prize in 1974. ... Geoffrey M. Cooper is a chairman and professor of biology at Boston University. ...

References

• This article contains material from the Science Primer published by the NCBI, which, as a U.S. government publication, is in the public domain.

1. ^ Cristianini, N. and Hahn, M. Introduction to Computational Genomics, Cambridge University Press, 2006. (ISBN-13: 9780521671910 | ISBN-10: 0521671914)

National Center for Biotechnology Information logo The National Center for Biotechnology Information (NCBI) is part of the United States National Library of Medicine (NLM), a branch of the National Institutes of Health. ... The public domain comprises the body of all creative works and other knowledge—writing, artwork, music, science, inventions, and others—in which no person or organization has any proprietary interest. ...

External links

Wikibooks has more on the topic of

Cell biology

• American Society for Cell Biology
• British Society for Cell Biology
• Cells Alive
• BMC Cell Biology - online journal, open access
• Journal of Cell Biology - older issues free
• Journal of Cell Science - older issues free
• Cell Biology - School and University - graphics
• Nature Reviews Molecular Cell Biology (journal home)
• The Virtual Library of Biochemistry and Cell Biology
• Centre of the Cell online resource

Image File history File links Wikibooks-logo-en. ... Wikibooks logo Wikibooks, previously called Wikimedia Free Textbook Project and Wikimedia-Textbooks, is a wiki for the creation of books. ... Molecular cell biology is a marriage of two distinct disciplines. ... Image File history File links This is a lossless scalable vector image. ... Wikiversity logo Wikiversity is a Wikimedia Foundation beta project[1], devoted to learning materials and activities, located at www. ...

Online cell biology textbooks

• Molecular Biology of the Cell fourth edition, edited by Bruce Alberts (2002) published by Garland Science.
• Molecular Cell Biology fourth edition, edited by Harvey Lodish (2000) published by W. H. Freeman and Company.
• The Cell - A Molecular Approach second edition, by Geoffrey M. Cooper (2000) published by Sinauer Associates.