Cell nucleus (a cell's information center) 

The cell nucleus is the most conspicuous organelle found in a eukaryotic cell. In Cell biology, the nucleus (pl nuclei; from Latin la ''nucleus'' or la ''nuculeus'' "little nut" or kernel is a membrane-enclosed Animals Plants fungi, and Protists are eukaryotes (juːˈkærɪɒt or -oʊt Organisms whose cells are organized into complex It houses the cell's chromosomes, and is the place where almost all DNA replication and RNA synthesis (transcription) occur. A chromosome is an organized structure of DNA and Protein that is found in cells. Deoxyribonucleic acid ( DNA) is a Nucleic acid that contains the genetic instructions used in the development and functioning of all known Ribonucleic acid ( RNA) is a Nucleic acid that consists of a long chain of Nucleotide units Transcription is the synthesis of RNA under the direction of DNA The nucleus is spherical in shape and separated from the cytoplasm by a double membrane called the nuclear envelope. The nuclear envelope (NE(also known as the perinuclear envelope, nuclear membrane, nucleolemma or karyotheca) is a double lipid bilayer that The nuclear envelope isolates and protects a cell's DNA from various molecules that could accidentally damage its structure or interfere with its processing. During processing, DNA is transcribed, or copied into a special RNA, called mRNA. Deoxyribonucleic acid ( DNA) is a Nucleic acid that contains the genetic instructions used in the development and functioning of all known Transcription is the synthesis of RNA under the direction of DNA Ribonucleic acid ( RNA) is a Nucleic acid that consists of a long chain of Nucleotide units Messenger ribonucleic acid ( mRNA) is a molecule of RNA encoding a chemical "blueprint" for a Protein product This mRNA is then transported out of the nucleus, where it is translated into a specific protein molecule. In prokaryotes, DNA processing takes place in the cytoplasm. The cytoplasm is the contents of a cell that is enclosed within the Plasma membrane.

Mitochondria and Chloroplasts (the power generators) 

Mitochondria are self-replicating organelles that occur in various numbers, shapes, and sizes in the cytoplasm of all eukaryotic cells. In Cell biology, a mitochondrion (plural mitochondria) is a membrane-enclosed Organelle found in most eukaryotic cells. Mitochondria contain their own genome, which is separate and distinct from the nuclear genome of a cell. They play a critical role in generating energy in the eukaryotic cell. Mitochondria give the cell energy by the process of respiration, adding oxygen to food (typically pertaining to glucose and ATP) to release energy. Oxygen (from the Greek roots ὀξύς (oxys (acid literally "sharp" from the taste of acids and -γενής (-genēs (producer literally begetteris the Glucose (Glc a Monosaccharide (or simple Sugar) also known as grape sugar, is an important Carbohydrate in Biology. Adenosine-5'-triphosphate ( ATP) is a multifunctional Nucleotide that is most important as a " molecular currency" of intracellular Energy Organelles that are modified chloroplasts are broadly called plastids, and are often involved in storage. Plastids are major Organelles found in plants and algae Plastids often contain pigments used in photosynthesis and the types of pigments present can change Since they contain their own genome, they are thought to have once been separate organisms, which later formed a symbiotic relationship with the cells. Chloroplasts are the counter-part of the mitochondria. Instead of giving off CO₂ and H₂O, plants give off glucose, oxygen, and 6 molecules of water (compared to 12 in respiration). This process is called photosynthesis.

Endoplasmic reticulum and Golgi apparatus (macromolecule managers) 

The endoplasmic reticulum (ER) is the transport network for molecules targeted for certain modifications and specific destinations, as compared to molecules that will float freely in the cytoplasm. The endoplasmic reticulum (Greek endo = "within" (prefix plásma = "formed entity" Latin reticulum = "little net" or ER, is an Organelle The ER has two forms: the rough ER, which has ribosomes on its surface, and the smooth ER, which lacks them. The primary function of the Golgi apparatus is to process and package the macromolecules such as proteins and lipids that are synthesized by the cell. The term macromolecule by definition implies "large Molecule " Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl Lipids are broadly defined as any fat- Soluble ( lipophilic) naturally-occurring Molecule, such as fats oils waxes cholesterol sterols fat-soluble It is particularly important in the processing of proteins for secretion. Secretion is the process of segregating elaborating and releasing chemicals from a cell, or a secreted Chemical substance or amount of substance The Golgi apparatus forms a part of the endomembrane system of eukaryotic cells. The endomembrane system is composed of the different membranes that are suspended in the Cytoplasm within a Eukaryotic cell. Also the Golgi apparatus's ends "pinch" off and become new vacuoles in the animal cell. The Golgi apparatus (also called the

Ribosomes (the protein production centers in the cell) 

The ribosome is a large complex of RNA and protein, composed of many molecules. Ribosomes ( from ribo nucleic acid and "Greek soma ( meaning body") are complexes of RNA and Protein that Ribonucleic acid ( RNA) is a Nucleic acid that consists of a long chain of Nucleotide units Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl In prokaryotes, ribosomes only exist floating freely in the cytosol, whereas in eukaryotes they can be found either free or bound to membranes.

Lysosomes and Peroxisomes (of the eukaryotic cell) 

Lysosomes contain digestive enzymes (acid hydrolases). Lysosomes are Organelles that contain Digestive enzymes (acid Hydrolases. Peroxisomes are Ubiquitous Organelles in Eukaryotes that participate in the metabolism of Fatty acids and other metabolites Digestion enzymes are Enzymes that break down Polymeric Macromolecules into their smaller building blocks In Biochemistry, a hydrolase is an Enzyme that catalyzes the Hydrolysis of a Chemical bond. They digest excess or worn-out organelles, food particles, and engulfed viruses or bacteria. In Cell biology, an organelle (pronunciation /ɔː(rgəˡnɛl/ is a specialized subunit within a cell that has a specific function and is usually separately enclosed A virus (from the Latin virus meaning Toxin or Poison) is a sub-microscopic infectious agent that is unable The Bacteria ( singular: bacterium) are a large group of unicellular Microorganisms Typically a few Micrometres in length bacteria have Peroxisomes have enzymes that rid the cell of toxic peroxides. A peroxide is a compound containing an Oxygen -oxygen single bond. The cell could not house these destructive enzymes if they were not contained in a membrane-bound system. These organelles are often called a "suicide bag" because of their ability to detonate and destroy the cell.

Centrosome (the cytoskeleton organiser) 

The centrosome produces the microtubules of a cell - a key component of the cytoskeleton. In Cell biology, the centrosome is an Organelle that serves as the main Microtubule organizing center (MTOC of the animal cell as well Microtubules are one of the components of the Cytoskeleton. They have a diameter of 25 nm and length varying from 200 nanometers to 25 micrometers cytoskeleton (also CSK is a cellular " Scaffolding " or " Skeleton " contained within the Cytoplasm. It directs the transport through the ER and the Golgi apparatus. The endoplasmic reticulum (Greek endo = "within" (prefix plásma = "formed entity" Latin reticulum = "little net" or ER, is an Organelle The Golgi apparatus (also called the Centrosomes are composed of two centrioles, which separate during cell division and help in the formation of the mitotic spindle. A Centriole is a barrel shaped Organelle found in most animal Eukaryotic cells though absent in Higher plants and Fungi. Cell division is a process by which a cell, called the parent cell divides into two or more cells called daughter cells. In Cell biology, the spindle apparatus (also called spindle fibers) is the structure that separate the Chromosomes into the daughter cells during A single centrosome is present in the animal cells. Animals Plants fungi, and Protists are eukaryotes (juːˈkærɪɒt or -oʊt Organisms whose cells are organized into complex They are also found in some fungi and algae cells.

Vacuoles 

Vacuoles store food and waste. In general vacuole functions include Removing unwanted structural debris Isolating materials that might be harmful or a threat to the cell Containing Some vacuoles store extra water. They are often described as liquid filled space and are surrounded by a membrane. Some cells, most notably Amoeba, have contractile vacuoles, which are able to pump water out of the cell if there is too much water. Amoeba (sometimes amœba or ameba, plural amoebae) is a Genus of Protozoa that moves

Structures outside the cell wall

Capsule

It is present only in some bacteria outside the cell wall. It is gelatinous in nature. The capsule may be polysaccharide as in pneumococci, meningococci or polypeptide as bacillus anthracis or hyaluronic acid as in streptococci. Capsules not stained by ordinary stain and can detected by special stain. The capsule is antigenic. The capsule has antiphagocytic function so it determines the virulence of many bacteria. It also plays a role in attachment of the organism to mucous membranes.

Flagella

Flagella are the organ of motility. A flagellum ( plural flagella) is a tail-like structure that projects from the Cell body of certain Prokaryotic and Eukaryotic cells and it They arise from cytoplasm and extrude through the cell wall. They are long and thick thread like appendages, protein in nature, formed of flagellin protein (antigenic). They can not be stained by gram stain. They have a special stain. According to their arrangement they may be monotrichate, amphitrichate, lophotrichate, peritrichate.

Fimbriae (pili)

They are short and thin hair like filaments, formed of protein called pilin (antigenic). Fimbriae are responsible for attachement of bacteria to specific receptors of human cell (adherence). There are special types of pili called (sex pili) involved in the process of conjunction.

Cell functions

Cell growth and metabolism

Main articles: Cell growth and Metabolism

Between successive cell divisions, cells grow through the functioning of cellular metabolism. The term cell growth is used in two different ways in Biology. Metabolism is the set of Chemical reactions that occur in living Organisms in order to maintain Life.

Cell metabolism is the process by which individual cells process nutrient molecules. Metabolism has two distinct divisions: catabolism, in which the cell breaks down complex molecules to produce energy and reducing power, and anabolism, in which the cell uses energy and reducing power to construct complex molecules and perform other biological functions. For the related metabolic process see Anabolism. Catabolism is the set of Metabolic pathways which break down molecules into Anabolism is the set of Metabolic pathways that construct molecules from smaller units Complex sugars consumed by the organism can be broken down into a less chemically-complex sugar molecule called glucose. Glucose (Glc a Monosaccharide (or simple Sugar) also known as grape sugar, is an important Carbohydrate in Biology. Once inside the cell, glucose is broken down to make adenosine triphosphate (ATP), a form of energy, via two different pathways. Adenosine-5'-triphosphate ( ATP) is a multifunctional Nucleotide that is most important as a " molecular currency" of intracellular Energy

The first pathway, glycolysis, requires no oxygen and is referred to as anaerobic metabolism. See also Gluconeogenesis, which carries out a process wherein glucose is synthesized rather than catabolized Fermentation is the process of deriving energy from the oxidation of organic compounds such as carbohydrates using an endogenous electron acceptor which is Each reaction is designed to produce some hydrogen ions that can then be used to make energy packets (ATP). In prokaryotes, glycolysis is the only method used for converting energy.

The second pathway, called the Krebs cycle, or citric acid cycle, occurs inside the mitochondria and is capable of generating enough ATP to run all the cell functions. The citric acid cycle, also known as the tricarboxylic acid cycle ( TCA cycle) or the Krebs cycle, (or rarely the Szent-Györgyi–Krebs cycle

An overview of protein synthesis.
Within the nucleus of the cell (light blue), genes (DNA, dark blue) are transcribed into RNA. In Cell biology, the nucleus (pl nuclei; from Latin la ''nucleus'' or la ''nuculeus'' "little nut" or kernel is a membrane-enclosed History See also History of genetics The existence of genes was first suggested by Gregor Mendel (1822-1884 who in the 1860s studied inheritance Transcription is the synthesis of RNA under the direction of DNA Ribonucleic acid ( RNA) is a Nucleic acid that consists of a long chain of Nucleotide units This RNA is then subject to post-transcriptional modification and control, resulting in a mature mRNA (red) that is then transported out of the nucleus and into the cytoplasm (peach), where it undergoes translation into a protein. Messenger ribonucleic acid ( mRNA) is a molecule of RNA encoding a chemical "blueprint" for a Protein product The cytoplasm is the contents of a cell that is enclosed within the Plasma membrane. Translation is the first stage of Protein biosynthesis (part of the overall process of Gene expression) mRNA is translated by ribosomes (purple) that match the three-base codons of the mRNA to the three-base anti-codons of the appropriate tRNA. Ribosomes ( from ribo nucleic acid and "Greek soma ( meaning body") are complexes of RNA and Protein that The genetic code is the set of rules by which information encoded in genetic material ( DNA or RNA sequences is translated into Proteins Transfer RNA (abbreviated tRNA) is a small RNA (usually about 74-95 nucleotides that transfers a specific Amino acid to a growing polypeptide chain at Newly-synthesized proteins (black) are often further modified, such as by binding to an effector molecule (orange), to become fully active.

Creation of new cells

Main article: Cell division

Cell division involves a single cell (called a mother cell) dividing into two daughter cells. Cell division is a process by which a cell, called the parent cell divides into two or more cells called daughter cells. This leads to growth in multicellular organisms (the growth of tissue) and to procreation (vegetative reproduction) in unicellular organisms. Multicellular organisms are Organisms consisting of more than one cell, and having Differentiated cells that perform specialized functions Tissue is a cellular organizational level intermediate between cells and a complete organism Vegetative reproduction is a type of Asexual reproduction found in plants and is also called vegetative propagation or vegetative multiplication. A microorganism (also spelled micro organism or micro-organism and also called a microbe) is an Organism that is Microscopic (usually

Prokaryotic cells divide by binary fission. The prokaryotes (proʊˈkærioʊts singular prokaryote /proʊˈkæriət/ are a group of Organisms that lack a Cell nucleus (= karyon or any other Binary fission is the form of Asexual reproduction and Cell division used by Prokaryotic organisms (such as Bacteria or Archea) Eukaryotic cells usually undergo a process of nuclear division, called mitosis, followed by division of the cell, called cytokinesis. Animals Plants fungi, and Protists are eukaryotes (juːˈkærɪɒt or -oʊt Organisms whose cells are organized into complex Mitosis is the process in which a Eukaryotic cell separates the Chromosomes in its Cell nucleus, into two identical sets in two daughter nuclei Cytokinesis is the process whereby the Cytoplasm of a single Eukaryotic cell is divided to form two daughter cells A diploid cell may also undergo meiosis to produce haploid cells, usually four. "Haplo" redirects here For the fictional character see The Death Gate Cycle. In Biology or life science meiosis (pronounced my-oh-sis is a process of reductional division in which the number of chromosomes per cell is cut in half Haploid cells serve as gametes in multicellular organisms, fusing to form new diploid cells. "Haplo" redirects here For the fictional character see The Death Gate Cycle. A gamete (from Ancient Greek γαμέτης; translated gamete = wife gametes = husband is a cell that fuses with another gamete

DNA replication, or the process of duplicating a cell's genome, is required every time a cell divides. DNA replication is the process of copying a double-stranded DNA molecule to form two double-stranded molecules Replication, like all cellular activities, requires specialized proteins for carrying out the job.

Protein synthesis

Main article: Protein biosynthesis

Cells are capable of synthesizing new proteins, which are essential for the modulation and maintenance of cellular activities. Protein biosynthesis (synthesis is the process in which cells build Proteins The term is sometimes used to refer only to protein translation but more This process involves the formation of new protein molecules from amino acid building blocks based on information encoded in DNA/RNA. In Chemistry, an amino acid is a Molecule containing both Amine and Carboxyl Functional groups In Biochemistry, this Protein synthesis generally consists of two major steps: transcription and translation. Transcription is the synthesis of RNA under the direction of DNA Translation is the first stage of Protein biosynthesis (part of the overall process of Gene expression)

Transcription is the process where genetic information in DNA is used to produce a complementary RNA strand. This RNA strand is then processed to give messenger RNA (mRNA), which is free to migrate through the cell. Messenger ribonucleic acid ( mRNA) is a molecule of RNA encoding a chemical "blueprint" for a Protein product mRNA molecules bind to protein-RNA complexes called ribosomes located in the cytosol, where they are translated into polypeptide sequences. Ribosomes ( from ribo nucleic acid and "Greek soma ( meaning body") are complexes of RNA and Protein that The cytosol or intracellular fluid (or cytoplasmic matrix) is the liquid found inside cells. The ribosome mediates the formation of a polypeptide sequence based on the mRNA sequence. The mRNA sequence directly relates to the polypeptide sequence by binding to transfer RNA (tRNA) adapter molecules in binding pockets within the ribosome. Transfer RNA (abbreviated tRNA) is a small RNA (usually about 74-95 nucleotides that transfers a specific Amino acid to a growing polypeptide chain at The new polypeptide then folds into a functional three-dimensional protein molecule.

Cell movement or motility

Cell has the ability to move spontaneously during the process of wound healing, immune response and cancer metastasis. The fastest moving cells in the human body are the spermaculi, which enter and exit through the penis. This was proven when Professor Julia Ertmann of UCLA observed changes in the reproductive spermaculi in a lab environment (circa 2005). For wound healing to occur, white blood cells and cells that ingest bacteria move to the wound site to kill the microorganisms that cause infection. A the same time fibroblasts (connective tissue cells) move there to remodel damaged structures. In the case of tumor development, cells from a primary tumor move away and spread to other parts of the body. Cell motility involves many receptors, crosslinking, bundling, binding, adhesion, motor and other proteins. ^[8] The process is divided into three steps - protrusion of the leading edge of the cell, adhesion of the leading edge and deadhesion at the cell body and rear, and cytoskeletal contraction to pull the cell forward. Each of these steps is driven by physical forces generated by unique segments of the cytoskeleton. ^[9][10]

Origins of cells

Main article: Origin of life

The origin of cells has to do with the origin of life, which began the history of life on Earth. In the Natural sciences, Abiogenesis, or origin of life, is the study of how Life on Earth emerged from Inanimate Organic This timeline of the evolution of life outlines the major events in the development The birth of the cell marked the passage from prebiotic chemistry to biological life.

Origin of the first cell

For more information, RNA world hypothesis

For more information, Last universal ancestor

The unit of selection in modern organisms and populations of organisms is not clear, with natural selection being proposed to work at the level of genes, cells, individual organisms, groups of organisms and even species. The RNA world hypothesis proposes that a world filled with life based on Ribonucleic acid (RNA predated current life based on Deoxyribonucleic acid (DNA The last universal ancestor ( LUA) also called the last universal common ancestor ( LUCA) the cenancestor or "number one" A unit of selection is a biological entity within the hierarchy of biological organisation (e Natural selection is the process by which favorable Heritable traits become more common in successive Generations of a Population of ^[11][12] None of these models are mutually-exclusive and selection may act on multiple levels simultaneously. ^[13] However, in a gene-centered view of evolution, life is regarded in terms of replicators—that is the DNA molecules in the organism. The gene-centered view of evolution, gene selection theory or selfish gene theory holds that Natural selection acts through differential survival of competing Deoxyribonucleic acid ( DNA) is a Nucleic acid that contains the genetic instructions used in the development and functioning of all known If freely-floating DNA molecules that code for enzymes are not enclosed in cells, the enzymes that benefit a given replicator (for example, by producing nucleotides) may do so less efficiently, and may in fact benefit competing replicators. Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins If the entire DNA molecule of a replicator is enclosed in a cell, then the enzymes coded from the molecule will be kept close to the DNA molecule itself. The replicator will directly benefit from its encoded enzymes.

Biochemically, cell-like spheroids formed by proteinoids are observed by heating amino acids with phosphoric acid as a catalyst. Proteinoids, or thermal proteins, are Protein -like molecules formed inorganically from Amino acids Some theories of Abiogenesis propose that In Chemistry, an amino acid is a Molecule containing both Amine and Carboxyl Functional groups In Biochemistry, this Phosphoric acid, also known as orthophosphoric acid or phosphoric(V acid, is a mineral (inorganic acid having the Chemical formula Catalysis is the process in which the rate of a Chemical reaction is increased by means of a Chemical substance known as a catalyst They bear many of the basic features provided by cell membranes. The cell membrane (also called the plasma membrane, plasmalemma, or "phospholipid bilayer" is a Selectively permeable Lipid bilayer Proteinoid-based protocells enclosing RNA molecules may have been the first cellular life forms on Earth. Some amphiphiles have the tendency to spontaneously form membranes in water. Amphiphile (from the Greek αμφις amphis both and φιλíα Philia: love friendship is a term describing a Chemical compound possessing both A spherically closed membrane contains water and is a hypothetical precursor to the modern cell membrane composed of proteins and phospholipid bilayer membranes. Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl Phospholipids are a class of Lipids and are a major component of all Biological membranes All phospholipids contain a Diglyceride, a Phosphate A lipid bilayer or bilayer lipid membrane ( BLM) is a membrane composed of Lipid molecules (usually Phospholipids.

Origin of eukaryotic cells

The eukaryotic cell seems to have evolved from a symbiotic community of prokaryotic cells. This article is about the biological phenomenon for other uses see Symbiosis (disambiguation The term symbiosis (from the Greek It is almost certain that DNA-bearing organelles like the mitochondria and the chloroplasts are what remains of ancient symbiotic oxygen-breathing proteobacteria and cyanobacteria, respectively, where the rest of the cell seems to be derived from an ancestral archaean prokaryote cell – a theory termed the endosymbiotic theory. In Cell biology, a mitochondrion (plural mitochondria) is a membrane-enclosed Organelle found in most eukaryotic cells. Chloroplasts are Organelles found in Plant cells and eukaryotic Algae that conduct Photosynthesis. The Proteobacteria are a major group ( Phylum) of Bacteria. They include a wide variety of Pathogens such as Escherichia, Cyanobacteria, also known as blue-green algae, blue-green bacteria or Cyanophyta, is a phylum of Bacteria that obtain their energy The endosymbiotic theory concerns the origins of mitochondria and Plastids (e

There is still considerable debate about whether organelles like the hydrogenosome predated the origin of mitochondria, or viceversa: see the hydrogen hypothesis for the origin of eukaryotic cells. A hydrogenosome is a membrane-enclosed Organelle of some anaerobic Ciliates trichomonads and Fungi. In Cell biology, a mitochondrion (plural mitochondria) is a membrane-enclosed Organelle found in most eukaryotic cells. The hydrogen hypothesis is a model proposed by William Martin and Miklós Müller in 1998 that describes a possible way in which the Mitochondrion arose as an endosymbiont

Sex, as the stereotyped choreography of meiosis and syngamy that persists in nearly all extant eukaryotes, may have played a role in the transition from prokaryotes to eukaryotes. An 'origin of sex as vaccination' theory suggests that the eukaryote genome accreted from prokaryan parasite genomes in numerous rounds of lateral gene transfer. Sex-as-syngamy (fusion sex) arose when infected hosts began swapping nuclearized genomes containing coevolved, vertically transmitted symbionts that conveyed protection against horizontal infection by more virulent symbionts. ^[14]

History

• 1632 – 1723: Antonie van Leeuwenhoek teaches himself to grind lenses, builds a microscope and draws protozoa, such as Vorticella from rain water, and bacteria from his own mouth. Antonie Philips van Leeuwenhoek (October 24 1632 &ndash August 30 1723 was a Dutch tradesman and Scientist from Delft, the Netherlands A lens is an optical device with perfect or approximate Axial symmetry which transmits and refracts Light, converging or diverging A microscope ( Greek: ( micron) = small + ( skopein) = to look or see is an instrument for viewing objects that are Protozoa (in Greek πρῶτον proton "first" and ζῷα zoia "animals" are unicellular Eukaryotes (singular Vorticella is a genus of Protozoa, with over 100 known species The Bacteria ( singular: bacterium) are a large group of unicellular Microorganisms Typically a few Micrometres in length bacteria have
• 1665: Robert Hooke discovers cells in cork, then in living plant tissue using an early microscope. Robert Hooke, FRS (18 July 1635 – 3 March 1703 was an English Natural philosopher and Polymath who played an important role in the ^[3]
• 1839: Theodor Schwann and Matthias Jakob Schleiden elucidate the principle that plants and animals are made of cells, concluding that cells are a common unit of structure and development, and thus founding the cell theory. Not to be confused with army general Theodore Schwan. ---- Theodor Schwann ( December 7, 1810 &ndash January Matthias Jakob Schleiden ( April 5, 1804 - June 23, 1881) was a German Botanist and co-founder of the Cell theory
• The belief that life forms are able to occur spontaneously (generatio spontanea) is contradicted by Louis Pasteur (1822 – 1895) (although Francesco Redi had performed an experiment in 1668 that suggested the same conclusion). In the Natural sciences, Abiogenesis, or origin of life, is the study of how Life on Earth emerged from Inanimate Organic Louis Pasteur (27 December 1822 – 28 September 1895 a French Chemist and Microbiologist, is best known for remarkable breakthroughs in the causes and Francesco Redi (February 18/19 1626&ndash March 1, 1697) was an Italian Physician.
• 1855: Rudolph Virchow states that cells always emerge from cell divisions (omnis cellula ex cellula). Rudolf Ludwig Karl Virchow ( 13 October 1821 &ndash 5 September 1902) was a German doctor, anthropologist, public health Cell division is a process by which a cell, called the parent cell divides into two or more cells called daughter cells.
• 1931: Ernst Ruska builds first transmission electron microscope (TEM) at the University of Berlin. Ernst August Friedrich Ruska ( December 25, 1906 &ndash May 27, 1988) was a German physicist. By 1935, he has built an EM with twice the resolution of a light microscope, revealing previously-unresolvable organelles.
• 1953: Watson and Crick made their first announcement on the double-helix structure for DNA on February 28. Francis Harry Compton Crick OM FRS (8 June 1916 – 28 July 2004 Ph A helix (pl helixes or helices) from the Greek word έλιξ, is a special kind of Space curve, i
• 1981: Lynn Margulis published Symbiosis in Cell Evolution detailing the endosymbiotic theory. Lynn Margulis (born March 5, 1938) is an American Biologist and University Professor in the Department of Geosciences The endosymbiotic theory concerns the origins of mitochondria and Plastids (e

See also

References

• This article contains material from the Science Primer published by the NCBI, which, as a U. The National Center for Biotechnology Information ( NCBI) is part of the United States National Library of Medicine (NLM a branch of the National Institutes S. government publication, is in the public domain. The public domain is a range of abstract materials &ndash commonly referred to as Intellectual property &ndash which are not owned or controlled by anyone

External links

• Virtual Cell's Educational Animations.
• Ixedu.com 3D Animations, Virtual Microscope, Activities, a Game and more! All about the cells.
• The Inner Life of A Cell, a flash video showing what happens inside of a cell
• The Virtual Cell
• Cells Alive!
• Journal of Cell Biology
• A comparison of the generational and exponential growth of cell populations
• High-resolution images of brain cells
• The Biology Project > Cell Biology
• The Image & Video Library of The American Society for Cell Biology, a collection of peer-reviewed still images, video clips and digital books that illustrate the structure, function and biology of the cell.
• Centre of the Cell online

Online textbooks

• Alberts B, Johnson A, Lewis J, Raff M, Roberts K, Walter P (2002). Molecular Biology of the Cell, 4th ed. , Garland. ISBN 0815332181.  

• Lodish H, Berk A, Matsudaira P, Kaiser CA, Krieger M, Scott MP, Zipurksy SL, Darnell J (2004). Molecular Cell Biology, 5th ed. , WH Freeman: New York, NY. ISBN 978-0716743668.  

• Cooper GM (2000). The cell: a molecular approach, 2nd ed. , Washington, D. C: ASM Press. ISBN 0-87893-102-3.  

• Gall JG, McIntosh JR, eds (2001). Landmark Papers in Cell Biology. Bethesda, MD and Cold Spring Harbor, NY: The American Society for Cell Biology and Cold Spring Harbor Laboratory Press; 2001. Commentaries and links to original research papers published in the ASCB Image & Video Library