Cell biology
Overview
 
Cell biology is a scientific discipline that studies cells
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....

 – their physiological
Physiology
Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...

 properties, their structure, the organelles they contain, interactions with their environment, their life cycle
Cell cycle
The cell cycle, or cell-division cycle, is the series of events that takes place in a cell leading to its division and duplication . In cells without a nucleus , the cell cycle occurs via a process termed binary fission...

, division
Cell division
Cell division is the process by which a parent cell divides into two or more daughter cells . Cell division is usually a small segment of a larger cell cycle. This type of cell division in eukaryotes is known as mitosis, and leaves the daughter cell capable of dividing again. The corresponding sort...

 and death
Apoptosis
Apoptosis is the process of programmed cell death that may occur in multicellular organisms. Biochemical events lead to characteristic cell changes and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, and chromosomal DNA fragmentation...

. This is done both on a microscopic
Microscope
A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...

 and molecular
Molecule
A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...

 level. Cell
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....

 biology research encompasses both the great diversity of single-celled organisms like bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

 and protozoa
Protozoa
Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...

, as well as the many specialized cells in multicellular organisms such as human
Human
Humans are the only living species in the Homo genus...

s.

Knowing the components of cells and how cells work is fundamental to all biological sciences
Biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...

.
Encyclopedia
Cell biology is a scientific discipline that studies cells
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....

 – their physiological
Physiology
Physiology is the science of the function of living systems. This includes how organisms, organ systems, organs, cells, and bio-molecules carry out the chemical or physical functions that exist in a living system. The highest honor awarded in physiology is the Nobel Prize in Physiology or...

 properties, their structure, the organelles they contain, interactions with their environment, their life cycle
Cell cycle
The cell cycle, or cell-division cycle, is the series of events that takes place in a cell leading to its division and duplication . In cells without a nucleus , the cell cycle occurs via a process termed binary fission...

, division
Cell division
Cell division is the process by which a parent cell divides into two or more daughter cells . Cell division is usually a small segment of a larger cell cycle. This type of cell division in eukaryotes is known as mitosis, and leaves the daughter cell capable of dividing again. The corresponding sort...

 and death
Apoptosis
Apoptosis is the process of programmed cell death that may occur in multicellular organisms. Biochemical events lead to characteristic cell changes and death. These changes include blebbing, cell shrinkage, nuclear fragmentation, chromatin condensation, and chromosomal DNA fragmentation...

. This is done both on a microscopic
Microscope
A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...

 and molecular
Molecule
A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...

 level. Cell
Cell (biology)
The cell is the basic structural and functional unit of all known living organisms. It is the smallest unit of life that is classified as a living thing, and is often called the building block of life. The Alberts text discusses how the "cellular building blocks" move to shape developing embryos....

 biology research encompasses both the great diversity of single-celled organisms like bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

 and protozoa
Protozoa
Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...

, as well as the many specialized cells in multicellular organisms such as human
Human
Humans are the only living species in the Homo genus...

s.

Knowing the components of cells and how cells work is fundamental to all biological sciences
Biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...

. Appreciating the similarities and differences between cell types is particularly important to the fields of cell and molecular biology
Molecular biology
Molecular biology is the branch of biology that deals with the molecular basis of biological activity. This field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry...

 as well as to biomedical fields such as cancer research
Cancer research
Cancer research is basic research into cancer in order to identify causes and develop strategies for prevention, diagnosis, treatments and cure....

 and developmental biology
Developmental biology
Developmental biology is the study of the process by which organisms grow and develop. Modern developmental biology studies the genetic control of cell growth, differentiation and "morphogenesis", which is the process that gives rise to tissues, organs and anatomy.- Related fields of study...

. These fundamental similarities and differences provide a unifying theme, sometimes allowing the principles
Principles
Principles may refer to:*Value *Principles and parameters*Principles...

 learned from studying one cell type to be extrapolated and generalized to other cell types. Therefore, research in cell biology is closely related to genetics
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....

, biochemistry
Biochemistry
Biochemistry, sometimes called biological chemistry, is the study of chemical processes in living organisms, including, but not limited to, living matter. Biochemistry governs all living organisms and living processes...

, molecular biology
Molecular biology
Molecular biology is the branch of biology that deals with the molecular basis of biological activity. This field overlaps with other areas of biology and chemistry, particularly genetics and biochemistry...

, immunology
Immunology
Immunology is a broad branch of biomedical science that covers the study of all aspects of the immune system in all organisms. It deals with the physiological functioning of the immune system in states of both health and diseases; malfunctions of the immune system in immunological disorders ; the...

, and developmental biology
Developmental biology
Developmental biology is the study of the process by which organisms grow and develop. Modern developmental biology studies the genetic control of cell growth, differentiation and "morphogenesis", which is the process that gives rise to tissues, organs and anatomy.- Related fields of study...

.

Movement of proteins

Each type of protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 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.

Most protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

s are synthesized by ribosome
Ribosome
A ribosome is a component of cells that assembles the twenty specific amino acid molecules to form the particular protein molecule determined by the nucleotide sequence of an RNA molecule....

s in the rough endoplasmic reticulum. This process is known as protein biosynthesis
Protein biosynthesis
Protein biosynthesis is the process in which cells build or manufacture proteins. The term is sometimes used to refer only to protein translation but more often it refers to a multi-step process, beginning with amino acid synthesis and transcription of nuclear DNA into messenger RNA, which is then...

. Biosynthesis (also called biogenesis) is an enzyme-catalyzed process in cells of living organisms by which substrates are converted to more complex products (also simply known as protein translation
Translation (genetics)
In molecular biology and genetics, translation is the third stage of protein biosynthesis . In translation, messenger RNA produced by transcription is decoded by the ribosome to produce a specific amino acid chain, or polypeptide, that will later fold into an active protein...

). Some proteins, such as those to be incorporated in membranes (known as membrane protein
Membrane protein
A membrane protein is a protein molecule that is attached to, or associated with the membrane of a cell or an organelle. More than half of all proteins interact with membranes.-Function:...

s), are transported into the "rough" endoplasmic reticulum
Endoplasmic reticulum
The endoplasmic reticulum is an organelle of cells in eukaryotic organisms that forms an interconnected network of tubules, vesicles, and cisternae...

 (ER) during synthesis. This process can be followed by transportation and processing in the Golgi apparatus
Golgi apparatus
The Golgi apparatus is an organelle found in most eukaryotic cells. It was identified in 1898 by the Italian physician Camillo Golgi, after whom the Golgi apparatus is named....

. From the Golgi, membrane proteins can move to the plasma membrane, to other sub-cellular 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
Kinesin
A kinesin is a protein belonging to a class of motor proteins found in eukaryotic cells. Kinesins move along microtubule filaments, and are powered by the hydrolysis of ATP . The active movement of kinesins supports several cellular functions including mitosis, meiosis and transport of cellular...

 transport membrane protein-containing vesicles along cytoskeletal
Cytoskeleton
The cytoskeleton is a cellular "scaffolding" or "skeleton" contained within a cell's cytoplasm and is made out of protein. The cytoskeleton is present in all cells; it was once thought to be unique to eukaryotes, but recent research has identified the prokaryotic cytoskeleton...

 tracks to distant parts of cells such as axon
Axon
An axon is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neuron's cell body or soma....

 terminals.

Some proteins that are made in the cytoplasm contain structural features
Nuclear localization signal
A nuclear localization signal or sequence is an amino acid sequence which 'tags' a protein for import into the cell nucleus by nuclear transport. Typically, this signal consists of one or more short sequences of positively charged lysines or arginines exposed on the protein surface. Different...

 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, chloroplast
Chloroplast
Chloroplasts are organelles found in plant cells and other eukaryotic organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of processes called photosynthesis.Chloroplasts are green...

s also make some cell proteins.

Extracellular and cell surface proteins destined to be degraded can move back into intracellular compartments upon being incorporated into endocytosed
Clathrin
Clathrin is a protein that plays a major role in the formation of coated vesicles. Clathrin was first isolated and named by Barbara Pearse in 1975. It forms a triskelion shape composed of three clathrin heavy chains and three light chains. When the triskelia interact they form a polyhedral lattice...

 vesicles some of which fuse with lysosome
Lysosome
thumb|350px|Schematic of typical animal cell, showing subcellular components. [[Organelle]]s: [[nucleoli]] [[cell nucleus|nucleus]] [[ribosomes]] [[vesicle |vesicle]] rough [[endoplasmic reticulum]]...

s where the proteins are broken down to their individual amino acid
Amino acid
Amino acids are molecules containing an amine group, a carboxylic acid group and a side-chain that varies between different amino acids. The key elements of an amino acid are carbon, hydrogen, oxygen, and nitrogen...

s. The degradation of some membrane proteins begins while still at the cell surface when they are separated by secretase
Secretase
Secretases are enzymes that "snip" pieces off a longer protein that is embedded in the cell membrane.thumb|300px|right|Processing of the amyloid precursor protein Among other roles in the cell, secretases act on the amyloid precursor protein to cleave the protein into three fragments...

s. Proteins that function in the cytoplasm are often degraded by proteasome
Proteasome
Proteasomes are very large protein complexes inside all eukaryotes and archaea, and in some bacteria.  In eukaryotes, they are located in the nucleus and the cytoplasm.  The main function of the proteasome is to degrade unneeded or damaged proteins by proteolysis, a chemical reaction that breaks...

s.

Other cellular processes

  • Active transport
    Active transport
    Active transport is the movement of a substance against its concentration gradient . In all cells, this is usually concerned with accumulating high concentrations of molecules that the cell needs, such as ions, glucose, and amino acids. If the process uses chemical energy, such as from adenosine...

     and Passive transport
    Passive transport
    Passive transport means moving biochemicals and other atomic or molecular substances across membranes. Unlike active transport, this process does not involve chemical energy, because, unlike in an active transport, the transport across membrane is always coupled with the growth of entropy of the...

     - Movement of molecules into and out of cells.
  • Autophagy
    Autophagy
    In cell biology, autophagy, or autophagocytosis, is a catabolic process involving the degradation of a cell's own components through the lysosomal machinery. It is a tightly regulated process that plays a normal part in cell growth, development, and homeostasis, helping to maintain a balance...

     - The process whereby cells "eat" their own internal components or microbial invaders.
  • Adhesion
    Cell adhesion
    Cellular adhesion is the binding of a cell to a surface, extracellular matrix or another cell using cell adhesion molecules such as selectins, integrins, and cadherins. Correct cellular adhesion is essential in maintaining multicellular structure...

     - Holding together cells and tissues.
  • Reproduction - Made possible by the combination of sperm made in the testiculi (contained in some male cells' nuclei) and the egg made in the ovary (contained in the nucleus of a female cell). When the sperm breaks through the hard outer shell of the egg a new cell embryo is formed, which, in humans, grows to full size in 9 months.
  • Cell movement: Chemotaxis
    Chemotaxis
    Chemotaxis is the phenomenon in which somatic cells, bacteria, and other single-cell or multicellular organisms direct their movements according to certain chemicals in their environment. This is important for bacteria to find food by swimming towards the highest concentration of food molecules,...

    , Contraction
    Muscle contraction
    Muscle fiber generates tension through the action of actin and myosin cross-bridge cycling. While under tension, the muscle may lengthen, shorten, or remain the same...

    , cilia and flagella
    Flagellum
    A flagellum is a tail-like projection that protrudes from the cell body of certain prokaryotic and eukaryotic cells, and plays the dual role of locomotion and sense organ, being sensitive to chemicals and temperatures outside the cell. There are some notable differences between prokaryotic and...

    .
  • Cell signaling
    Cell signaling
    Cell signaling is part of a complex system of communication that governs basic cellular activities and coordinates cell actions. The ability of cells to perceive and correctly respond to their microenvironment is the basis of development, tissue repair, and immunity as well as normal tissue...

     - Regulation of cell behavior by signals from outside.
  • DNA repair
    DNA repair
    DNA repair refers to a collection of processes by which a cell identifies and corrects damage to the DNA molecules that encode its genome. In human cells, both normal metabolic activities and environmental factors such as UV light and radiation can cause DNA damage, resulting in as many as 1...

     and Cell death
  • Metabolism
    Metabolism
    Metabolism is the set of chemical reactions that happen in the cells of living organisms to sustain life. These processes allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Metabolism is usually divided into two categories...

    : Glycolysis
    Glycolysis
    Glycolysis is the metabolic pathway that converts glucose C6H12O6, into pyruvate, CH3COCOO− + H+...

    , respiration
    Cellular respiration
    Cellular respiration is the set of the metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients into adenosine triphosphate , and then release waste products. The reactions involved in respiration are catabolic reactions that involve...

    , Photosynthesis
    Photosynthesis
    Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...

  • Transcription
    Transcription (genetics)
    Transcription is the process of creating a complementary RNA copy of a sequence of DNA. Both RNA and DNA are nucleic acids, which use base pairs of nucleotides as a complementary language that can be converted back and forth from DNA to RNA by the action of the correct enzymes...

     and mRNA splicing
    Splicing (genetics)
    In molecular biology and genetics, splicing is a modification of an RNA after transcription, in which introns are removed and exons are joined. This is needed for the typical eukaryotic messenger RNA before it can be used to produce a correct protein through translation...

     - gene expression.

Internal cellular structures

  • Chloroplast
    Chloroplast
    Chloroplasts are organelles found in plant cells and other eukaryotic organisms that conduct photosynthesis. Chloroplasts capture light energy to conserve free energy in the form of ATP and reduce NADP to NADPH through a complex set of processes called photosynthesis.Chloroplasts are green...

     - key organelle
    Organelle
    In cell biology, an organelle is a specialized subunit within a cell that has a specific function, and is usually separately enclosed within its own lipid bilayer....

     for photosynthesis
    Photosynthesis
    Photosynthesis is a chemical process that converts carbon dioxide into organic compounds, especially sugars, using the energy from sunlight. Photosynthesis occurs in plants, algae, and many species of bacteria, but not in archaea. Photosynthetic organisms are called photoautotrophs, since they can...

     (only found in plant cells)
  • Cilia - motile microtubule
    Microtubule
    Microtubules are a component of the cytoskeleton. These rope-like polymers of tubulin can grow as long as 25 micrometers and are highly dynamic. The outer diameter of microtubule is about 25 nm. Microtubules are important for maintaining cell structure, providing platforms for intracellular...

    -containing structures of eukaryote
    Eukaryote
    A eukaryote is an organism whose cells contain complex structures enclosed within membranes. Eukaryotes may more formally be referred to as the taxon Eukarya or Eukaryota. The defining membrane-bound structure that sets eukaryotic cells apart from prokaryotic cells is the nucleus, or nuclear...

    s
  • Cytoplasm
    Cytoplasm
    The cytoplasm is a small gel-like substance residing between the cell membrane holding all the cell's internal sub-structures , except for the nucleus. All the contents of the cells of prokaryote organisms are contained within the cytoplasm...

     - contents of the main fluid-filled space inside cells
  • Cytoskeleton
    Cytoskeleton
    The cytoskeleton is a cellular "scaffolding" or "skeleton" contained within a cell's cytoplasm and is made out of protein. The cytoskeleton is present in all cells; it was once thought to be unique to eukaryotes, but recent research has identified the prokaryotic cytoskeleton...

     - protein filaments inside cells
  • Endoplasmic reticulum
    Endoplasmic reticulum
    The endoplasmic reticulum is an organelle of cells in eukaryotic organisms that forms an interconnected network of tubules, vesicles, and cisternae...

     - major site of membrane protein synthesis
  • Flagella - motile structures of bacteria
    Bacteria
    Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

    , archaea
    Archaea
    The Archaea are a group of single-celled microorganisms. A single individual or species from this domain is called an archaeon...

     and eukaryotes
  • Golgi apparatus
    Golgi apparatus
    The Golgi apparatus is an organelle found in most eukaryotic cells. It was identified in 1898 by the Italian physician Camillo Golgi, after whom the Golgi apparatus is named....

     - site of protein glycosylation
    Glycosylation
    Glycosylation is the reaction in which a carbohydrate, i.e. a glycosyl donor, is attached to a hydroxyl or other functional group of another molecule . In biology glycosylation refers to the enzymatic process that attaches glycans to proteins, lipids, or other organic molecules...

     in the endomembrane system
  • Lipid bilayer
    Lipid bilayer
    The lipid bilayer is a thin membrane made of two layers of lipid molecules. These membranes are flat sheets that form a continuous barrier around cells. The cell membrane of almost all living organisms and many viruses are made of a lipid bilayer, as are the membranes surrounding the cell nucleus...

     - fundamental organizational structure of cell membrane
    Cell membrane
    The cell membrane or plasma membrane is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells. It basically protects the cell...

    s
  • Lysosome
    Lysosome
    thumb|350px|Schematic of typical animal cell, showing subcellular components. [[Organelle]]s: [[nucleoli]] [[cell nucleus|nucleus]] [[ribosomes]] [[vesicle |vesicle]] rough [[endoplasmic reticulum]]...

     - break down cellular waste products and debris into simple compounds (only found in animal cells)
  • Membrane
    Cell membrane
    The cell membrane or plasma membrane is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells. It basically protects the cell...

     lipid
    Lipid
    Lipids constitute a broad group of naturally occurring molecules that include fats, waxes, sterols, fat-soluble vitamins , monoglycerides, diglycerides, triglycerides, phospholipids, and others...

     and protein
    Protein
    Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

     barrier
  • Mitochondrion
    Mitochondrion
    In cell biology, a mitochondrion is a membrane-enclosed organelle found in most eukaryotic cells. These organelles range from 0.5 to 1.0 micrometers in diameter...

     - major energy-producing organelle by releasing it in the form of ATP
  • Nucleus
    Cell nucleus
    In cell biology, the nucleus is a membrane-enclosed organelle found in eukaryotic cells. It contains most of the cell's genetic material, organized as multiple long linear DNA molecules in complex with a large variety of proteins, such as histones, to form chromosomes. The genes within these...

     - holds most of the DNA
    DNA
    Deoxyribonucleic acid is a nucleic acid that contains the genetic instructions used in the development and functioning of all known living organisms . The DNA segments that carry this genetic information are called genes, but other DNA sequences have structural purposes, or are involved in...

     of eukaryotic cells and controls all cellular activities
  • Organelle
    Organelle
    In cell biology, an organelle is a specialized subunit within a cell that has a specific function, and is usually separately enclosed within its own lipid bilayer....

     - term used for major subcellular structures
  • Ribosome
    Ribosome
    A ribosome is a component of cells that assembles the twenty specific amino acid molecules to form the particular protein molecule determined by the nucleotide sequence of an RNA molecule....

     - RNA
    RNA
    Ribonucleic acid , or RNA, is one of the three major macromolecules that are essential for all known forms of life....

     and protein complex required for protein synthesis in cells
  • Vesicle
    Vesicle (biology)
    A vesicle is a bubble of liquid within another liquid, a supramolecular assembly made up of many different molecules. More technically, a vesicle is a small membrane-enclosed sack that can store or transport substances. Vesicles can form naturally because of the properties of lipid membranes , or...

     - small membrane-bounded spheres inside cells

Techniques used to study cells

Cells may be observed under the microscope. This includes the Optical Microscope
Optical microscope
The optical microscope, often referred to as the "light microscope", is a type of microscope which uses visible light and a system of lenses to magnify images of small samples. Optical microscopes are the oldest design of microscope and were possibly designed in their present compound form in the...

, Transmission Electron Microscope, Scanning Electron Microscope
Scanning electron microscope
A scanning electron microscope is a type of electron microscope that images a sample by scanning it with a high-energy beam of electrons in a raster scan pattern...

, Fluorescence Microscope
Fluorescence microscope
A fluorescence microscope is an optical microscope used to study properties of organic or inorganic substances using the phenomena of fluorescence and phosphorescence instead of, or in addition to, reflection and absorption...

, and by Confocal Microscopy
Confocal microscopy
Confocal microscopy is an optical imaging technique used to increase optical resolution and contrast of a micrograph by using point illumination and a spatial pinhole to eliminate out-of-focus light in specimens that are thicker than the focal plane. It enables the reconstruction of...

.

Several different techniques exist to study cells are
  • Cell culture
    Cell culture
    Cell culture is the complex process by which cells are grown under controlled conditions. In practice, the term "cell culture" has come to refer to the culturing of cells derived from singlecellular eukaryotes, especially animal cells. However, there are also cultures of plants, fungi and microbes,...

     is the basic technique of growing cells in a laboratory independent of an organism.
  • Immunostaining
    Immunostaining
    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. The term immunostaining was originally used to refer to the immunohistochemical staining of tissue sections, as first described by Albert Coons in 1941...

    , also known as immunohistochemistry
    Immunohistochemistry
    Immunohistochemistry or IHC refers to the process of detecting antigens in cells of a tissue section by exploiting the principle of antibodies binding specifically to antigens in biological tissues. IHC takes its name from the roots "immuno," in reference to antibodies used in the procedure, and...

    , is a specialized histological method used to localize proteins in cells or tissue slices. Unlike regular histology, which uses stains to identify cells, cellular components or protein classes, immunostaining requires the reaction of an antibody directed against the protein of interest within the tissue or cell. Through the use of proper controls and published protocols (need to add reference links here), specificity of the antibody-antigen reaction can be achieved. Once this complex is formed, it is identified via either a "tag" attached directly to the antibody, or added in an additional technical step. Commonly used "tags" include fluorophores or enzymes. In the case of the former, detection of the location of the "immuno-stained" protein occurs via fluorescence microscopy. With an enzymatic tag, such as horse radish peroxidase, a chemical reaction is carried out that results in a dark color in the location of the protein of interest. This darkened pattern is then detected using light microscopy.
  • Computational genomics
    Computational genomics
    Computational genomics refers to the use of computational analysis to decipher biology from genome sequences and related data , including both DNA and RNA sequence as well as other "post-genomic" data...

     is used to find patterns in genomic information
  • DNA microarray
    DNA microarray
    A DNA microarray is a collection of microscopic DNA spots attached to a solid surface. Scientists use DNA microarrays to measure the expression levels of large numbers of genes simultaneously or to genotype multiple regions of a genome...

    s identify changes in transcript levels between different experimental conditions.
  • Gene knockdown
    Gene knockdown
    Gene knockdown refers to techniques by which the expression of one or more of an organism's genes is reduced, either through genetic modification or by treatment with a reagent such as a short DNA or RNA oligonucleotide with a sequence complementary to either an mRNA transcript or a gene...

     mutates a selected gene.
  • In situ hybridization
    In situ hybridization
    In situ hybridization is a type of hybridization that uses a labeled complementary DNA or RNA strand to localize a specific DNA or RNA sequence in a portion or section of tissue , or, if the tissue is small enough , in the entire tissue...

     shows which cells are expressing a particular RNA transcript.
  • PCR can be used to determine how many copies of a gene are present in a cell.
  • Transfection
    Transfection
    Transfection is the process of deliberately introducing nucleic acids into cells. The term is used notably for non-viral methods in eukaryotic cells...

     introduces a new gene into a cell, usually an expression construct


Purification of cells and their parts
Purification may be performed using the following methods:
  • Cell fractionation
    Cell fractionation
    Cell fractionation is the separation of homogeneous sets, usually organelles, from a heterogeneous population of cells.-Steps:There are three principal steps involved:#Disruption of cells and liberation of organelles.#Macro Filtration...

    • Release of cellular organelles by disruption of cells.
    • Separation of different organelles by centrifugation
      Centrifugation
      Centrifugation is a process that involves the use of the centrifugal force for the sedimentation of mixtures with a centrifuge, used in industry and in laboratory settings. More-dense components of the mixture migrate away from the axis of the centrifuge, while less-dense components of the mixture...

      .
  • Flow cytometry
    Flow cytometry
    Flow cytometry is a technique for counting and examining microscopic particles, such as cells and chromosomes, by suspending them in a stream of fluid and passing them by an electronic detection apparatus. It allows simultaneous multiparametric analysis of the physical and/or chemical...

  • Immunoprecipitation
    Immunoprecipitation
    Immunoprecipitation is the technique of precipitating a protein antigen out of solution using an antibody that specifically binds to that particular protein. This process can be used to isolate and concentrate a particular protein from a sample containing many thousands of different proteins...

  • Proteins extracted from cell membrane
    Cell membrane
    The cell membrane or plasma membrane is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells. It basically protects the cell...

    s by detergent
    Detergent
    A detergent is a surfactant or a mixture of surfactants with "cleaning properties in dilute solutions." In common usage, "detergent" refers to alkylbenzenesulfonates, a family of compounds that are similar to soap but are less affected by hard water...

    s and salt
    Salt
    In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...

    s or other kinds of chemicals.

See also

  • Cell disruption
    Cell disruption
    Cell disruption is a method or process for releasing biological molecules from inside a cell.- Choice of disruption method:The production of biologically-interesting molecules using cloning and culturing methods allows the study and manufacture of relevant molecules.Except for excreted molecules,...

  • Cellular microbiology
    Cellular microbiology
    Cellular microbiology is a discipline that bridges microbiology and cell biology.The term "cellular microbiology" was coined in 1996 in a Science article...

  • Important publications in cell biology
  • Institute of Molecular and Cell Biology
    Institute of Molecular and Cell Biology
    Institute of Molecular and Cell Biology may refer to:*Institute of Molecular and Cell Biology , a research institute in Porto, Portugal.*Institute of Molecular and Cell Biology , a research institute in Singapore....

  • Prokaryotic cell
  • The American Society for Cell Biology
    The American Society for Cell Biology
    American Society for Cell Biology is a learned society that was founded in 1960.Its mission statement states:- History :On 6 April 1959 the United States National Academy of Sciences passed a resolution for the establishment of a "national society of cell biology to act as a national...

  • Cell physiology
    Cell physiology
    Cell physiology is the biological study of the cell's mechanism and interaction in its environment. The term "physiology" refers to all the normal functions that take place in a living organism. Absorption of water by roots, production of food in the leaves, and growth of shoots towards light are...


Notable cell biologists

  • Peter Agre
    Peter Agre
    Peter Agre is an American medical doctor, professor, and molecular biologist who was awarded the 2003 Nobel Prize in Chemistry for his discovery of aquaporins. Aquaporins are water-channel proteins that move water molecules through the cell membrane...

  • Günter Blobel
    Günter Blobel
    -Biography:Blobel was born in Waltersdorf in the Prussian Province of Lower Silesia. In January 1945 his family fled from native Silesia from the advancing Red Army. On their way to the West they passed through the beautiful old city of Dresden, which left deep impressions in the young boy...

  • Geoffrey M. Cooper
    Geoffrey M. Cooper
    Geoffrey M. Cooper is a chairman and professor of biology at Boston University. He earned his Ph.D. at the University of Miami in 1973 working with nobel laureate Howard Temin. His work includes cellular growth control, cancer, and signal transduction...

  • Christian de Duve
    Christian de Duve
    Christian René, viscount de Duve is a Nobel Prize-winning cytologist and biochemist. De Duve was born in Thames Ditton, Surrey, Great Britain, as a son of Belgian refugees. They returned to Belgium in 1920...

  • Robert Hooke
    Robert Hooke
    Robert Hooke FRS was an English natural philosopher, architect and polymath.His adult life comprised three distinct periods: as a scientific inquirer lacking money; achieving great wealth and standing through his reputation for hard work and scrupulous honesty following the great fire of 1666, but...

  • H. Robert Horvitz
    H. Robert Horvitz
    Howard Robert Horvitz is an American biologist best known for his research on the nematode worm Caenorhabditis elegans.-Life:Horvitz did his undergraduate studies at MIT in 1968, where he joined Alpha Epsilon Pi...

  • Marc Kirschner
    Marc Kirschner
    Professor Marc W. Kirschner is an American cell biologist.- Biography :Kirschner graduated from Northwestern University in 1966 and in 1971 received his doctorate from the University of California, Berkeley. He held post-doc positions at Berkeley and at the University of Oxford in England. He...

  • Anton van Leeuwenhoek
    Anton van Leeuwenhoek
    Antonie Philips van Leeuwenhoek was a Dutch tradesman and scientist from Delft, Netherlands. He is commonly known as "the Father of Microbiology", and considered to be the first microbiologist...

  • Ira Mellman
    Ira Mellman
    Ira Mellman, Ph.D. is an American cell biologist who discovered endosomes. He serves as Vice President of Research Oncology at Genentech in South San Francisco, California.-Research:...

  • Peter D. Mitchell
    Peter D. Mitchell
    Peter Dennis Mitchell, FRS was a British biochemist who was awarded the 1978 Nobel Prize for Chemistry for his discovery of the chemiosmotic mechanism of ATP synthesis.Mitchell was born in Mitcham, Surrey, England....

  • Paul Nurse
    Paul Nurse
    Sir Paul Maxime Nurse, PRS is a British geneticist and cell biologist. He was awarded the 2001 Nobel Prize in Physiology or Medicine with Leland H. Hartwell and R...

  • George Emil Palade
    George Emil Palade
    George Emil Palade was a Romanian cell biologist. Described as "the most influential cell biologist ever", in 1974 he was awarded the Nobel Prize in Physiology and Medicine, together with Albert Claude and Christian de Duve. The prize was granted for his innovations in electron microscopy and...

  • Keith R. Porter
    Keith R. Porter
    Keith Roberts Porter was a Canadian cell biologist. He did pioneering biology research using electron microscopy of cells , such as work on the 9 + 2 microtubule structure in the axoneme of cilia. Porter also contributed to the development of other experimental methods for cell culture and nuclear...

  • Jan Evangelista Purkyně
    Jan Evangelista Purkyne
    Jan Evangelista Purkyně was a Czech anatomist and physiologist. He was one of the best known scientists of his time. His son was the painter Karel Purkyně...

  • Ray Rappaport
    Ray Rappaport
    Ray Rappaport was an American cell biologist. He did pioneering research using physical manipulations of cells to understand the mechanisms of cytokinesis, the process by which a cell's cytoplasm is divided in two....

  • Michael Swann
    Michael Swann
    Michael Meredith Swann, Baron Swann, FRS was a distinguished molecular and cell biologist working on the mechanisms of cell division and fertilisation. He used cell polarisation methods to understand the changes in molecular organisation of the mitotic spindle...

  • Roger Tsien
  • Edmund Beecher Wilson
    Edmund Beecher Wilson
    Edmund Beecher Wilson was a pioneering American zoologist and geneticist. He wrote one of the most famous textbooks in the history of modern biology, The Cell.- Career :...

  • Kenneth R. Miller
    Kenneth R. Miller
    Kenneth Raymond Miller is a biology professor at Brown University. Miller, who is Roman Catholic, is particularly known for his opposition to creationism, including the intelligent design movement...


External links

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