The chemical reactions and pathways resulting in the formation of GTP, guanosine triphosphate.

The chemical reactions and pathways resulting in the formation of UTP, uridine (5'-)triphosphate.

The chemical reactions and pathways resulting in the formation of CTP, cytidine 5'-triphosphate.

The chemical reactions and pathways by which a nucleobase, nucleoside or nucleotide small molecule is synthesized from another nucleobase, nucleoside or nucleotide small molecule.

The process of introducing a phosphate group into a nucleoside diphosphate to produce a nucleoside triphosphate.

The chemical reactions and pathways resulting in the formation of a nucleoside triphosphate, a compound consisting of a nucleobase linked to a deoxyribose or ribose sugar esterified with triphosphate on the sugar.

A programmed cell death process which begins when a cell receives an internal (e.g. DNA damage) or external signal (e.g. an extracellular death ligand), and proceeds through a series of biochemical events (signaling pathway phase) which trigger an execution phase. The execution phase is the last step of an apoptotic process, and is typically characterized by rounding-up of the cell, retraction of pseudopodes, reduction of cellular volume (pyknosis), chromatin condensation, nuclear fragmentation (karyorrhexis), plasma membrane blebbing and fragmentation of the cell into apoptotic bodies. When the execution phase is completed, the cell has died.

A series of molecular signals initiated by the binding of extracellular ligand to an integrin on the surface of a target cell, and ending with regulation of a downstream cellular process, e.g. transcription.

Any process that activates or increases the frequency, rate or extent of cellular DNA-templated transcription.

Any process that activates or increases the frequency, rate or extent of transcription from an RNA polymerase II promoter.

Any process that activates or increases the rate or extent of epithelial cell proliferation.

The process of introducing a phosphate group into a nucleoside diphosphate to produce a nucleoside triphosphate.

Any process that stops, prevents, or reduces the frequency, rate, or extent of myeloid leukocyte differentiation.

The process of introducing a phosphate group into a nucleoside diphosphate to produce a nucleoside triphosphate.

The chemical reactions and pathways resulting in the formation of GTP, guanosine triphosphate.

The chemical reactions and pathways resulting in the formation of GTP, guanosine triphosphate.

Any process that increases the rate, frequency or extent of neuron projection development. Neuron projection development is the process whose specific outcome is the progression of a neuron projection over time, from its formation to the mature structure. A neuron projection is any process extending from a neural cell, such as axons or dendrites (collectively called neurites).

Any process that activates or increases the rate or extent of epithelial cell proliferation.

The attachment of a cell, either to another cell or to an underlying substrate such as the extracellular matrix, via cell adhesion molecules.

A series of molecular signals initiated by the binding of extracellular ligand to an integrin on the surface of a target cell, and ending with regulation of a downstream cellular process, e.g. transcription.

The chemical reactions and pathways resulting in the formation of a nucleoside triphosphate, a compound consisting of a nucleobase linked to a deoxyribose or ribose sugar esterified with triphosphate on the sugar.

Any process that stops, prevents, or reduces the frequency, rate or extent of cell death by apoptotic process.

Any process that stops, prevents, or reduces the frequency, rate or extent of cell death by apoptotic process.

The regulated exocytosis of secretory granules containing preformed mediators such as proteases, lipases, and inflammatory mediators by a neutrophil.

Any process that activates or increases the frequency, rate or extent of keratinocyte differentiation.

Any process that activates or increases the frequency, rate or extent of keratinocyte differentiation.

Any process that modulates the frequency, rate or extent of epidermis development.

Any process that modulates the frequency, rate or extent of epidermis development.

Any process that activates or increases the frequency, rate or extent of cellular DNA-templated transcription.

Any process that activates or increases the frequency, rate or extent of cellular DNA-templated transcription.

Any process that activates or increases the frequency, rate or extent of transcription from an RNA polymerase II promoter.

Any process that activates or increases the rate or extent of epithelial cell proliferation.

Any process that modulates the frequency, rate or extent of angiogenesis.

The phosphorylation by a protein of one or more of its own amino acid residues (cis-autophosphorylation), or residues on an identical protein (trans-autophosphorylation).

Progression through the phases of the mitotic cell cycle, the most common eukaryotic cell cycle, which canonically comprises four successive phases called G1, S, G2, and M and includes replication of the genome and the subsequent segregation of chromosomes into daughter cells. In some variant cell cycles nuclear replication or nuclear division may not be followed by cell division, or G1 and G2 phases may be absent.

The process of introducing a phosphate group into a nucleoside diphosphate to produce a nucleoside triphosphate.

The chemical reactions and pathways resulting in the formation of GTP, guanosine triphosphate.

The chemical reactions and pathways resulting in the formation of UTP, uridine (5'-)triphosphate.

The chemical reactions and pathways resulting in the formation of UTP, uridine (5'-)triphosphate.

The chemical reactions and pathways resulting in the formation of UTP, uridine (5'-)triphosphate.

The chemical reactions and pathways resulting in the formation of CTP, cytidine 5'-triphosphate.

The chemical reactions and pathways resulting in the formation of CTP, cytidine 5'-triphosphate.

The chemical reactions and pathways resulting in the formation of CTP, cytidine 5'-triphosphate.

The process of introducing a phosphate group on to a protein.

The process of introducing a phosphate group on to a protein.

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a stimulus indicating damage to its DNA from environmental insults or errors during metabolism.

Any cellular process that depends upon or alters the microtubule cytoskeleton, that part of the cytoskeleton comprising microtubules and their associated proteins.

The series of molecular signals generated as a consequence of a G protein-coupled receptor binding to its physiological ligand, where the pathway proceeds through activation of adenylyl cyclase activity and a subsequent increase in the concentration of cyclic AMP (cAMP).

A series of molecular signals initiated by the binding of extracellular ligand to an integrin on the surface of a target cell, and ending with regulation of a downstream cellular process, e.g. transcription.

The process whose specific outcome is the progression of an open tracheal system over time, from its formation to the mature structure. An open tracheal system is a respiratory system, a branched network of epithelial tubes that supplies oxygen to target tissues via spiracles. An example of this is found in Drosophila melanogaster.

The process whose specific outcome is the progression of an open tracheal system over time, from its formation to the mature structure. An open tracheal system is a respiratory system, a branched network of epithelial tubes that supplies oxygen to target tissues via spiracles. An example of this is found in Drosophila melanogaster.

The orderly movement of epithelial cells during development of an open tracheal system. An example of this is found in Drosophila melanogaster.

The regulated release of milk from the mammary glands and the period of time that a mother lactates to feed her young.

Any process that stops, prevents or reduces the rate or extent of cell proliferation.

The chemical reactions and pathways involving a nucleotide, a nucleoside that is esterified with (ortho)phosphate or an oligophosphate at any hydroxyl group on the glycose moiety; may be mono-, di- or triphosphate; this definition includes cyclic nucleotides (nucleoside cyclic phosphates).

The chemical reactions and pathways resulting in the formation of a nucleoside triphosphate, a compound consisting of a nucleobase linked to a deoxyribose or ribose sugar esterified with triphosphate on the sugar.

Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of an ultraviolet radiation (UV light) stimulus. Ultraviolet radiation is electromagnetic radiation with a wavelength in the range of 10 to 380 nanometers.

The sequence of reactions within a cell required to convert absorbed photons from red or far-red light into a molecular signal; the red, far-red light range is defined as having a wavelength within the range 660-730 nm.

A series of molecular signals generated by the binding of the plant hormone auxin to a receptor, and ending with modulation of a downstream cellular process, e.g. transcription.

Any process that modulates the frequency, rate or extent of gene expression after the production of an RNA transcript.

Any process that decreases the frequency, rate or extent of gene expression. Gene expression is the process in which a gene's coding sequence is converted into a mature gene product or products (proteins or RNA). This includes the production of an RNA transcript as well as any processing to produce a mature RNA product or an mRNA or circRNA (for protein-coding genes) and the translation of that mRNA or circRNA into protein. Protein maturation is included when required to form an active form of a product from an inactive precursor form.

Any cellular process that results in the specification, formation or maintenance of a polarized follicular epithelial sheet.

The phosphorylation of peptidyl-serine to form peptidyl-O-phospho-L-serine.

The process whose specific outcome is the progression of the mammary gland over time, from its formation to the mature structure. The mammary gland is a large compound sebaceous gland that in female mammals is modified to secrete milk. Its development starts with the formation of the mammary line and ends as the mature gland cycles between nursing and weaning stages.

A process that is carried out at the cellular level which results in the assembly, arrangement of constituent parts, or disassembly of an adherens junction. An adherens junction is a cell junction at which the cytoplasmic face of the plasma membrane is attached to actin filaments.

Ensuring that tracheal cells form and maintain tubular structures with the correct size and shape for their position in the network. This is essential for efficient flow of gases through the tracheal network.

Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a hydrogen peroxide (H2O2) stimulus.

Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a hydrogen peroxide (H2O2) stimulus.

Any process that modulates the occurrence or rate of cell death by apoptotic process.

Any process that stops, prevents, or reduces the frequency, rate or extent of cell death by apoptotic process.

Any process that increases the frequency, rate or extent of DNA binding. DNA binding is any process in which a gene product interacts selectively with DNA (deoxyribonucleic acid).

Any process that increases the frequency, rate or extent of DNA binding. DNA binding is any process in which a gene product interacts selectively with DNA (deoxyribonucleic acid).

Any process that activates or increases the frequency, rate or extent of keratinocyte differentiation.

Any process that modulates the frequency, rate or extent of epidermis development.

Any process that activates or increases the frequency, rate or extent of cellular DNA-templated transcription.

Any process that activates or increases the frequency, rate or extent of transcription from an RNA polymerase II promoter.

The phosphorylation by a protein of one or more of its own amino acid residues (cis-autophosphorylation), or residues on an identical protein (trans-autophosphorylation).

The process of creating protein oligomers, compounds composed of a small number, usually between three and ten, of component monomers; protein oligomers may be composed of different or identical monomers. Oligomers may be formed by the polymerization of a number of monomers or the depolymerization of a large protein polymer.

Any process that stops, prevents, or reduces the frequency, rate, or extent of myeloid leukocyte differentiation.

Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a stimulus from a bacterium.

Any process that increases the rate, frequency or extent of neuron projection development. Neuron projection development is the process whose specific outcome is the progression of a neuron projection over time, from its formation to the mature structure. A neuron projection is any process extending from a neural cell, such as axons or dendrites (collectively called neurites).

The formation of a protein hexamer, a macromolecular structure consisting of six noncovalently associated identical or nonidentical subunits.

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a hydrogen peroxide (H2O2) stimulus.

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a glucose stimulus.

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a fatty acid stimulus.

Any process that activates or increases the frequency, rate or extent of an adenylate cyclase-activating G protein-coupled receptor signaling pathway.

The chemical reactions and pathways resulting in the formation of GTP, guanosine triphosphate.

The process of introducing a phosphate group into dGDP, deoxyguanosine diphosphate, to produce dGTP.

The chemical reactions and pathways resulting in the formation of dGTP, deoxyguanosine triphosphate (2'-deoxyguanosine 5'-triphosphate) from other compounds, including gGDP, deoxyguanosine diphosphate.

The chemical reactions and pathways resulting in the formation of UTP, uridine (5'-)triphosphate.

The chemical reactions and pathways resulting in the formation of CTP, cytidine 5'-triphosphate.

The chemical reactions and pathways resulting in the formation of CTP, cytidine 5'-triphosphate.

The successive addition of amino acid residues to a nascent polypeptide chain during protein biosynthesis.

The chemical reactions and pathways involving phospholipids, any lipid containing phosphoric acid as a mono- or diester.

The directed movement of lipids into, out of or within a cell, or between cells, by means of some agent such as a transporter or pore. Lipids are compounds soluble in an organic solvent but not, or sparingly, in an aqueous solvent.

The directed movement of lipids into, out of or within a cell, or between cells, by means of some agent such as a transporter or pore. Lipids are compounds soluble in an organic solvent but not, or sparingly, in an aqueous solvent.

A series of molecular signals that proceeds with an activated receptor promoting the exchange of GDP for GTP on the alpha-subunit of an associated heterotrimeric G-protein complex. The GTP-bound activated alpha-G-protein then dissociates from the beta- and gamma-subunits to further transmit the signal within the cell. The pathway begins with receptor-ligand interaction, or for basal GPCR signaling the pathway begins with the receptor activating its G protein in the absence of an agonist, and ends with regulation of a downstream cellular process, e.g. transcription. The pathway can start from the plasma membrane, Golgi or nuclear membrane (PMID:24568158 and PMID:16902576).

The series of molecular signals generated as a consequence of a G protein-coupled receptor binding to its physiological ligand, where the pathway proceeds through activation of adenylyl cyclase activity and a subsequent increase in the concentration of cyclic AMP (cAMP).

The chemical reactions and pathways involving a nucleoside, a nucleobase linked to either beta-D-ribofuranose (a ribonucleoside) or 2-deoxy-beta-D-ribofuranose, (a deoxyribonucleoside), e.g. adenosine, guanosine, inosine, cytidine, uridine and deoxyadenosine, deoxyguanosine, deoxycytidine and thymidine (= deoxythymidine).

Any process that decreases the frequency, rate or extent of gene expression. Gene expression is the process in which a gene's coding sequence is converted into a mature gene product or products (proteins or RNA). This includes the production of an RNA transcript as well as any processing to produce a mature RNA product or an mRNA or circRNA (for protein-coding genes) and the translation of that mRNA or circRNA into protein. Protein maturation is included when required to form an active form of a product from an inactive precursor form.

Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of an amine stimulus. An amine is a compound formally derived from ammonia by replacing one, two or three hydrogen atoms by hydrocarbyl groups.

The biological process in which new individuals are produced by either a single cell or a group of cells, in the absence of any sexual process.

The progression of the hippocampus over time from its initial formation until its mature state.

A process that is carried out at the cellular level which results in the assembly, arrangement of constituent parts, or disassembly of cytoskeletal structures comprising actin filaments and their associated proteins.

Any process that modulates the frequency, rate or extent of cell migration.

Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a testosterone stimulus.

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of oxidative stress, a state often resulting from exposure to high levels of reactive oxygen species, e.g. superoxide anions, hydrogen peroxide (H2O2), and hydroxyl radicals.

Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a drug stimulus. A drug is a substance used in the diagnosis, treatment or prevention of a disease.

Any process that activates or increases the frequency, rate or extent of development of the vulva. Vulval development is the process whose specific outcome is the progression of the egg-laying organ of female and hermaphrodite nematodes over time, from its formation to the mature structure. In nematodes, the vulva is formed from ventral epidermal cells during larval stages to give rise to a fully formed vulva in the adult.

Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a drug stimulus. A drug is a substance used in the diagnosis, treatment or prevention of a disease.

Any process that activates or increases the frequency, rate or extent of signal transduction mediated by the MAPK cascade.

Any process that stops, prevents, or reduces the frequency, rate or extent of exocytosis.

Any process that stops, prevents, or reduces the frequency, rate or extent of pinocytosis. Pinocytosis is the process in which cells take in liquid material from their external environment; literally 'cell drinking'. Liquid is enclosed in vesicles, formed by invagination of the plasma membrane. These vesicles then move into the cell and pass their contents to endosomes.

Any process that stops, prevents, or reduces the frequency, rate or extent of phagocytosis.

The process in which a cell irreversibly increases in size in one or more axes, where the growth rate varies according to the direction of growth. Growth may be limited to a particular axis, axes, or to particular locations on the surface of the cell.

The process of creating protein oligomers, compounds composed of a small number, usually between three and ten, of component monomers; protein oligomers may be composed of different or identical monomers. Oligomers may be formed by the polymerization of a number of monomers or the depolymerization of a large protein polymer.

Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a cAMP (cyclic AMP, adenosine 3',5'-cyclophosphate) stimulus.

Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a growth hormone stimulus. Growth hormone is a peptide hormone that binds to the growth hormone receptor and stimulates growth.

The process of introducing a phosphate group into CDP to produce a CTP.

Any process that modulates the frequency, rate or extent of engulfment of apoptotic cell.

The part of the cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes.

Projection at the leading edge of a crawling cell; the protrusions are supported by a microfilament meshwork.

All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures.

A thin sheetlike process extended by the leading edge of a migrating cell or extending cell process; contains a dense meshwork of actin filaments.

A semiautonomous, self replicating organelle that occurs in varying numbers, shapes, and sizes in the cytoplasm of virtually all eukaryotic cells. It is notably the site of tissue respiration.

The part of the cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes.

A membrane-bounded organelle of eukaryotic cells in which chromosomes are housed and replicated. In most cells, the nucleus contains all of the cell's chromosomes except the organellar chromosomes, and is the site of RNA synthesis and processing. In some species, or in specialized cell types, RNA metabolism or DNA replication may be absent.

A membrane-bounded organelle of eukaryotic cells in which chromosomes are housed and replicated. In most cells, the nucleus contains all of the cell's chromosomes except the organellar chromosomes, and is the site of RNA synthesis and processing. In some species, or in specialized cell types, RNA metabolism or DNA replication may be absent.

A vesicle that is released into the extracellular region by fusion of the limiting endosomal membrane of a multivesicular body with the plasma membrane. Extracellular exosomes, also simply called exosomes, have a diameter of about 40-100 nm.

All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures.

The part of a cell encompassing the cell cortex, the plasma membrane, and any external encapsulating structures.

The part of the cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes.

An electrically insulating fatty layer that surrounds the axons of many neurons. It is an outgrowth of glial cells: Schwann cells supply the myelin for peripheral neurons while oligodendrocytes supply it to those of the central nervous system.

Cytoplasm situated near, or occurring around, the nucleus.

Projection at the leading edge of a crawling cell; the protrusions are supported by a microfilament meshwork.

The space external to the outermost structure of a cell. For cells without external protective or external encapsulating structures this refers to space outside of the plasma membrane. This term covers the host cell environment outside an intracellular parasite.

A thin sheetlike process extended by the leading edge of a migrating cell or extending cell process; contains a dense meshwork of actin filaments.

The volume enclosed by the membrane of a secretory granule.

The part of a cell encompassing the cell cortex, the plasma membrane, and any external encapsulating structures.

Any membrane-enclosed lumen that is part of a ficolin-1-rich granule.

All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures.

A semiautonomous, self replicating organelle that occurs in varying numbers, shapes, and sizes in the cytoplasm of virtually all eukaryotic cells. It is notably the site of tissue respiration.

The region between the inner and outer lipid bilayers of the mitochondrial envelope.

Projection at the leading edge of a crawling cell; the protrusions are supported by a microfilament meshwork.

A membrane-bounded organelle of eukaryotic cells in which chromosomes are housed and replicated. In most cells, the nucleus contains all of the cell's chromosomes except the organellar chromosomes, and is the site of RNA synthesis and processing. In some species, or in specialized cell types, RNA metabolism or DNA replication may be absent.

A membrane-bounded organelle of eukaryotic cells in which chromosomes are housed and replicated. In most cells, the nucleus contains all of the cell's chromosomes except the organellar chromosomes, and is the site of RNA synthesis and processing. In some species, or in specialized cell types, RNA metabolism or DNA replication may be absent.

All of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures.

The outer, i.e. cytoplasm-facing, lipid bilayer of the mitochondrial envelope.

A structure comprised of a core structure (in most organisms, a pair of centrioles) and peripheral material from which a microtubule-based structure, such as a spindle apparatus, is organized. Centrosomes occur close to the nucleus during interphase in many eukaryotic cells, though in animal cells it changes continually during the cell-division cycle.

Any of the long, generally straight, hollow tubes of internal diameter 12-15 nm and external diameter 24 nm found in a wide variety of eukaryotic cells; each consists (usually) of 13 protofilaments of polymeric tubulin, staggered in such a manner that the tubulin monomers are arranged in a helical pattern on the microtubular surface, and with the alpha/beta axes of the tubulin subunits parallel to the long axis of the tubule; exist in equilibrium with pool of tubulin monomers and can be rapidly assembled or disassembled in response to physiological stimuli; concerned with force generation, e.g. in the spindle.

Any microtubule in the nucleus of a cell.

The membrane surrounding a cell that separates the cell from its external environment. It consists of a phospholipid bilayer and associated proteins.

A chlorophyll-containing plastid with thylakoids organized into grana and frets, or stroma thylakoids, and embedded in a stroma.

The space enclosed by the double membrane of a chloroplast but excluding the thylakoid space. It contains DNA, ribosomes and some temporary products of photosynthesis.

A membranous cellular structure that bears the photosynthetic pigments in plants, algae, and cyanobacteria. In cyanobacteria thylakoids are of various shapes and are attached to, or continuous with, the plasma membrane. In eukaryotes they are flattened, membrane-bounded disk-like structures located in the chloroplasts; in the chloroplasts of higher plants the thylakoids form dense stacks called grana. Isolated thylakoid preparations can carry out photosynthetic electron transport and the associated phosphorylation.

The double lipid bilayer enclosing the chloroplast and separating its contents from the rest of the cytoplasm; includes the intermembrane space.

A lipid bilayer along with all the proteins and protein complexes embedded in it an attached to it.

A lipid bilayer along with all the proteins and protein complexes embedded in it an attached to it.

A thin sheetlike process extended by the leading edge of a migrating cell or extending cell process; contains a dense meshwork of actin filaments.

Either of the lipid bilayers that surround the mitochondrion and form the mitochondrial envelope.

The portion of the plasma membrane surrounding a ruffle.

The portion of the plasma membrane surrounding a ruffle.

The part of a cell encompassing the cell cortex, the plasma membrane, and any external encapsulating structures.

All of the contents of a cilium, excluding the plasma membrane surrounding the cilium.

The region between the inner and outer lipid bilayers of the mitochondrial envelope.

A membrane-bounded intracellular vesicle that arises from the ingestion of particulate material by phagocytosis.

Cytoplasm situated near, or occurring around, the nucleus.

An extracellular matrix lying external to fungal cells. The fungal biofilm matrix consists of polysaccharides, proteins, lipids, and nucleic acids. Fungal biofilms mediate adherence to host tissues, and provide protection from host immune defenses.

The space external to the outermost structure of a cell. For cells without external protective or external encapsulating structures this refers to space outside of the plasma membrane. This term covers the host cell environment outside an intracellular parasite.

That part of a multicellular organism outside the cells proper, usually taken to be outside the plasma membranes, and occupied by fluid.

A semiautonomous, self replicating organelle that occurs in varying numbers, shapes, and sizes in the cytoplasm of virtually all eukaryotic cells. It is notably the site of tissue respiration.

A semiautonomous, self replicating organelle that occurs in varying numbers, shapes, and sizes in the cytoplasm of virtually all eukaryotic cells. It is notably the site of tissue respiration.

A semiautonomous, self replicating organelle that occurs in varying numbers, shapes, and sizes in the cytoplasm of virtually all eukaryotic cells. It is notably the site of tissue respiration.

The outer, i.e. cytoplasm-facing, lipid bilayer of the mitochondrial envelope.

The inner, i.e. lumen-facing, lipid bilayer of the mitochondrial envelope. It is highly folded to form cristae.

A structure comprised of a core structure (in most organisms, a pair of centrioles) and peripheral material from which a microtubule-based structure, such as a spindle apparatus, is organized. Centrosomes occur close to the nucleus during interphase in many eukaryotic cells, though in animal cells it changes continually during the cell-division cycle.

The part of the cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes.

An intracellular organelle, about 200 A in diameter, consisting of RNA and protein. It is the site of protein biosynthesis resulting from translation of messenger RNA (mRNA). It consists of two subunits, one large and one small, each containing only protein and RNA. Both the ribosome and its subunits are characterized by their sedimentation coefficients, expressed in Svedberg units (symbol: S). Hence, the prokaryotic ribosome (70S) comprises a large (50S) subunit and a small (30S) subunit, while the eukaryotic ribosome (80S) comprises a large (60S) subunit and a small (40S) subunit. Two sites on the ribosomal large subunit are involved in translation, namely the aminoacyl site (A site) and peptidyl site (P site). Ribosomes from prokaryotes, eukaryotes, mitochondria, and chloroplasts have characteristically distinct ribosomal proteins.

Any of the various filamentous elements that form the internal framework of cells, and typically remain after treatment of the cells with mild detergent to remove membrane constituents and soluble components of the cytoplasm. The term embraces intermediate filaments, microfilaments, microtubules, the microtrabecular lattice, and other structures characterized by a polymeric filamentous nature and long-range order within the cell. The various elements of the cytoskeleton not only serve in the maintenance of cellular shape but also have roles in other cellular functions, including cellular movement, cell division, endocytosis, and movement of organelles.

Any microtubule in the nucleus of a cell.

The membrane surrounding a cell that separates the cell from its external environment. It consists of a phospholipid bilayer and associated proteins.

A lipid bilayer along with all the proteins and protein complexes embedded in it an attached to it.

A small subcellular vesicle, surrounded by a membrane, that is formed from the Golgi apparatus and contains a highly concentrated protein destined for secretion. Secretory granules move towards the periphery of the cell and upon stimulation, their membranes fuse with the cell membrane, and their protein load is exteriorized. Processing of the contained protein may take place in secretory granules.

A structure lying external to one or more cells, which provides structural support, biochemical or biomechanical cues for cells or tissues.

Either of the lipid bilayers that surround the mitochondrion and form the mitochondrial envelope.

All of the contents of a cilium, excluding the plasma membrane surrounding the cilium.