Lodish Cellular and Molecular Biology Glossary
Nuclear transport
Movement of macromolecules into or out of the nucleus mediated by nuclear transport receptors
Membrane transport
Movement of molecules across a membrane mediated by a membrane transport protein
CaM-kinase II
Multifunctional Ca2+/calmodulin-dependent protein kinase found in all animal cells that undergoes autohphosphorylation when activated. It is especially abundant in brain and has a role in learning and memory
Beta-catenin
Multifunctional cytoplasmic protein involved in cadherin-mediated-cell-cell adhesion. Links cadherins to the actin cytoskeleton. Also a gene regulatory protein.
Degenerate
Multiple states that amount for the same thing. Different triplet combinations of nucleotide bases (codons) that come for the same amino acid
TOM complex
Multisubunit protein complex that transports proteins across the mitochondrial outer membrane.
Striated muscle
Muscle composed of transversely striped (striated) myofibrils. Skeletal and heart muscle of vertebrates are the best known examples.
Homeotic mutation
Mutation that causes cells in one region of the body to behave as through they were located in another, causing a bizarre disturbance of the body plan
Lethal mutation
Mutation that causes the death of the cell or the organism that contains it
Dominant negative mutation
Mutation that dominantly affects the phenotype by the production of a defective protein or RNA that interferes with the function of the normal gene product in the same cell
Photosystem
Mutliprotein complex involved in photosynthesis that captures the energy of sunlight and converts it to useful forms of energy.
Linkage analysis
Mutual effect of the binding of one ligand on the binding of another that is a central feature of the behavior of all allosteric proteins. Co-inhertiance of two genetic loci that lie near each other on the same chromosome. The closer two loci, the lower the frequency of recombination between them
ER signal sequence
N-terminal signal sequence that directs proteins to enter the ER. It is cleaved off by signal peptidase after entry
Electron
Negatively charged subatomic particle that generally occupies orbitals surrounding the nucleus in an atom
Osmosis
Net movement of water molecules across a semipermeable membrane driven by a difference in concentration of solute on either side. The membrane must be permeable to water but not to the solute molecules
trans Golgi network (TGN)
Network of interconnected cisternae and tubules at the trans face of the Golgi apparatus, through which material is transferred out of the Golgi.
cis Golgi network
Network of interconnected cisternae and tubules which receives vesicles from the endoplasmic reticulum and transfers material to the cis face
Sarcoplasmic reticulum
Network of internal membranes in the cytoplasm of a muscle cell that contains high concentrations of sequestered Ca2+ which is released into the cytosol during muscle excitation.
Cell-cycle control system
Network of regulatory proteins that governs progression of an eukaryotic cell through the cell cycle
Acetylcholine
Neurotransmitter at the vertebrate nervous system. Functions in brain and peripheral nervous system.
Inhibitory neurotransmitter
Neurotransmitter that opens transmitter-gated Cl- or K+ channels in the postsynaptic membrane of a nerve or muscle cell and tends to inhibit action potential generation
Alkaloid
Nitrogen-containing metabolite produced by plants as a defense against herbivores (caffeine, morphine, colchicine)
Innate immune response
Non-specific Immune response to a pathogen that involves the pre-existing defenses of the body such as barriers formed by skin and mucosa, antimicrobial molecules and phagocytes
Intron
Noncoding region of an eukaryotic gene that is transcribed into an RNA molecule but is then excised by RNA splicing during production of a messengerRNA
Hydrogen bond
Nonycovalent bond in which an electropositive hydrogen atom is partially shared by two electronegative atoms
Proto-oncogene
Normal gene, usually concerned with the regulation of cell proliferation, that can be converted into a cancer-promoting oncogene by mutation.
Bright-field microscope
Normal light microscope in which the image is obtained by simple transmission of light through the object
Wild-type
Normal, nonmutant form of an organism; the form found in nature (in the wild)
Adenosine triphosphate (ATP)
Nucleoside triphosphate made of adenine, ribose and three phosphate groups. Principal carrier of energy in cells. The hydrolysis of phosphate groups releases high amounts of energy
Nucleotide
Nucleoside with one or more phosphate groups joined in ester linkages to the sugar. DNA or RNA are polymers of nucleotides
Adenosine diphosphate (ADP)
Nucleotide generated by the hydrolysis of ATP. It can regenerate ATP through oxidative phosphorylation
Cyclic AMP
Nucleotide generated from ATP by adenylyl cyclase in response to simulation of cell-surface receptors. cAMP acts as an intracellular signaling molecule by activating cyclic-amp-depedent kinases. Hydrolyzed to AMP by a phosphodiesterase https://o.quizlet.com/Uyy-4E1CHSWMkuUzrfPMXA_m.png
Promoter
Nucleotide sequence in DNA to which RNA polymerase binds to begin transcription.
Palindromic sequence
Nucleotide sequence that is identical to its complementary strand when each is read in the same chemical direction (e.g. GATC)
Atomic weight
Number of protons and neurons in an atom
Colony stimulating factor
Numerous signal molecules that control differentiation of blood cells
Yolk
Nutritional reserves rich in lipids, proteins and polysaccharides, present in the eggs of many animals.
Chromatid
One copy of a chromosome formed by DNA replication that is still joined at the centromere to the other copy
Inositol phospholipids
One of a family of lipids containing phosphorylated inositol derivates. Important in signal transduction, present in plasma membrane
Histone
One of a group of small abundant proteins rich in arginine and lysine, positively charged that associated with DNA in nucleosomes
MHC molecule
One of a large family of ubiquitous cell-surface glycoproteins encoded by genes of the major histocompatibility complex. They bind peptide fragments of foreign antigens and present them to T cells to induce immune response https://o.quizlet.com/KxCSS7WCy8Rmk97y7oaTYA_m.jpg
Restriction nuclease (restriction enzyme)
One of a large number of nucleases that can cleave a DNA molecule at any site where a specific short sequence of nucleotides occurs. Extensively used in recombinant DNA technology.
Isotope
One of a number of atom forms that differ in atomic weight but have the same number of protons and electrons and therefore have the same chemistry. Can be stable or radioactive
Somite
One of a series of paired blocks of mesoderm that forms during early development and lie on either side of the notochord in a vertebrate embryo. They give rise to the vertebral column, muscles and associated connective tissue. Each somite produces the musculature of one vertebrate segment, plus associated connective tissue.
Follicle cell
One of the cell types that surround a developing oocyte or egg
Blastomere
One of the cells formed by the cleavage of a fertilized egg https://o.quizlet.com/9BEVR4mekntK33oWt5465Q_m.png
Crista
One of the folds on inner mitochondrial membrane. Sensory structure in inner ear https://o.quizlet.com/DjAKAp8gm-e0zsGbiGKYsw_m.png
Light chain
One of the smaller polypeptides of a multisubunit protein such as myosin or immunoglobulin
Pyrimidine
One of the two categories of nitrogen-containing ring compounds found in DNA and RNA. Cytosine, thymine, and uracil are pyrimidines.
Purine
One of the two categories of nitrogen-containing ring compounds found in DNA and RNA. Examples are adenine and guanine.
Bacteria
One of the two major divisions of prokaryotes. Unicellular organisms, some are pathogenic
Leading strand
One of the two newly synthesized strands of DNA found at a replication fork. Made by continuous synthesis in the 5' to 3' direction
Lagging strand
One of the two newly synthesized strands of DNA found on a replication fork. Made in discontinuous lengths that are later joined covalently
Kinesin
One type of motor protein that uses the energy of ATP hydrolysis to move along a microtubule https://o.quizlet.com/e0ufvyyL8GqaZsK4Sq7dOw_m.jpg
Chloroplast
Organelle found in green algae and plants that contains chlorophyll and carries out photosynthesis. Special plastid
Aldehyde
Organic compound that contains a 0=C-H group. Oxidized to an acid or reduced to an alcohol
Amino acid
Organic molecule composed of an amino and a carboxyl group that serves as building blocks of proteins
Ketone
Organic molecule containing a carbonyl group linked to alkyl groups https://o.quizlet.com/y91Sgcgmg1cTpc8I.JfIlQ_m.png
Caged molecule
Organic molecule that is activated by light of a specific wavelength
Lipid
Organic molecule that is insoluble in water but tends to dissolver in non polar organic solvents. Phospholipids form the structural basis of biological membranes
Eukaryote
Organism composed of one or more cells with a distinct nucleus and cytoplasm and membrane-bounded organelles. Includes all forms of life except viruses and prokaryotes
Mutant
Organism in which a mutation has occurred that makes it different from wild type or from the "normal" extent of variation in the population
Temperature-sensitive (ts) mutant
Organism or cell carrying a genetically altered protein (or RNA molecule) that performs normally at one temperature but is abnormal at another (usually higher) temperature.
Lymphoid organ
Organs involved in the production or function of lymphocytes, such as thymus, spleen, lymph nodes, and tonsil
Outer membrane
Outermost of the two membranes surrounding an organelle, the membrane adjacent to the cytosol
Coupled reaction
Pair of chemical reactions in which the free energy released by one of the reactions serves to drive the other
Redox pair
Pair of molecules in which one acts as an electron donor and one as an electron acceptor in an oxidation-reduction reaction; for example, NADH (electron donor) and NAD+ (electron acceptor).
Lampbrush chromosome
Paired chromosome in meiosis in immature amphibian eggs in which the chromatin forms large stiff loops extending out form the linear axis of the chromosome
Antenna complex
Part of a photosystem that captures light E and channels it into the photochemical reaction center. Protein complexes bond to large numbers of chlorophyll molecules and pigments. https://o.quizlet.com/ECYfdv-Sb1RnV8Z350VB.A_m.png
Cell-mediated immune response
Part of an adaptive immune response in which antigen specific T cells are activated to perform various functions such as killing infected cells an activating macrophages
Ribosome
Particle composed of ribosomal RNAs and ribosomal proteins that associates with messenger RNA and catalyzes the synthesis of protein.
Virus
Particle consisting of nucleic acid (RNA or DNA) enclosed in a protein coat and capable of replicating within a host cell and spreading from cell to cell. Many viruses cause disease.
Diffusion
Passive movement of molecules from higher to low concentration regions (along a concentration gradient)
Autoimmune disease
Pathological state in which the body mounts an immune response against one or more of its own potential antigens
Classical pathway
Pathway for activating the complement system that is initiated by IgG or IgM antibodies bound to the surface
Constitutive secretory pathway
Pathway present in all cells by which molecules are continually delivered into the plasma membrane from the Gogli apparatus in vesicles that fuse with the plasma membrane
Diffraction pattern
Pattern set up by wave interference between radiation transmitted or scattered by different parts of an object
Neuropeptide
Peptide secreted by neurons as a signaling molecule either at synapses or elsewhere
S phase
Period of a eukaryotic cell cycle in which DNA is synthesized.
M phase
Period of eukaryotic cycle during which the nucleus and cytoplasm divide
Aqueous
Pertaining to water
Macrophage
Phagocytic cell derived from blood monocytes, typically resident in most tissues. It has both scavenger and antigen presenting functions in immune responses
Prometaphase
Phase of mitosis preceding metaphase in which the nuclear envelope breaks down and chromosomes first attach to the spindle.
Cooperativity
Phenomenon in which the binding of one ligand to a target molecule promotes the binding of successive ligands. Seen in the assembly of large complexes and enzymes and receptors with allosteric subunits https://o.quizlet.com/fwgarCeCgbWOImUhVvRSgA_m.png
Replicative cell senescence
Phenomenon observed in primary cell cultures as they age, in which cell proliferation slows down and finally halts.
Micrograph
Photograph of an image seen through a light or electron microscope
Rod photoreceptor (rod)
Photoreceptor cell type in the retina that is responsible for non-color vision in dim light.
Noncyclic photophosphorylation
Photosynthetic process that produces both ATP and NADPH in plants and cyanobacteria
Cleavage
Physical splitting of a cell into two or a specialized type of cell division seen in early embryos whereby a large cell divides into smaller cells without growth
Microelectrode, micropipette
Piece of fine glass tubing pulled to an even finer tip. Used to penetrate a cell to study its physiology or to inject electric current or molecules
Bacteriorhodopsin
Pigmented protein that pumps protons out of the cell in response to light. Found in plasma membrane of a halobacteria
Transgenic organism
Plant or animal that has stably incorporated one or more genes from another cell or organism and can pass them on to successive generations.
Z disc (Z line)
Plate-like region of a muscle sarcomere to which the plus ends of actin filaments are attached. Seen as a dark transverse line in micrographs.
Checkpoint
Point in the eukaryotic cell division cycle where progress through the cycle can be halted until conditions are suitable for the cell to proceed to the next stage
Alcohol
Polar organic molecule that contains a hydroxyl group bound to a carbon atom other than an aromatic ring
Ribonucleic acid (RNA)
Polymer formed from covalently linked ribonucleotide monomers.
DNA
Polynucleotide formed from covalently linked deoxyribonucleotides units. Serves as the store of hereditary information within a cell and carries it from generation to generation
Insulin
Polypeptide hormone secreted by beta cells in the pancreas that helps regulate glucose metabolism in animals
Glycogen
Polysaccharide composed exclusively of glucose units used to store energy in animal cells. Its large granules are especially abundant in liver and muscle cells
Starch
Polysaccharide composed exclusively of glucose units, used as an energy storage material in plant cells.
Clone
Population of cells/organisms formed by repeated division from a common cell/organism or to produce many copies of a gene by repeated cycles of replication
Immune system
Population of lymphocytes and other white blood cells in the vertebrate body that defends it against infection
Cell line
Population of plant/animal cells capable of dividing indefinitely in culture
Protein domain
Portion of a protein that has a tertiary structure of its own. Larger proteins are generally composed of several domains, each connected to the next by short flexible regions of polypeptide chain.
Locus
Position of a gene on a chromosome. Different alleles of the same gene all occupy the same
Proton
Positively charged subatomic particle that forms part of an atomic nucleus. Hydrogen has a nucleus composed of a single proton (H+).
Protein glycosylation
Post-translational addition of oligosaccharide side chains to a protein.
Malaria
Potentially fatal human disease caused by the protozoan Plasmodium, transmitted by the bite of an infected mosquito
Germ cell
Precursor cell that will give rise to gametes
giga
Prefix denoting 10 to the 9
Milli
Prefix denoting 10^-3
Micro
Prefix denoting 10^-6
mega-
Prefix denoting 10^6
nano
Prefix denoting 10^9
Kilo
Prefix donating 10^3
Class I MHC molecule
Present on almost all cell types and presents viral peptides on the surface of virus-infected cells where they are recognized by T cells
Gene conversion
Process by which DNA sequence information can be transferred from one DNA helix (which remains unchanged) to another whose sequences is altered. The mechanism involves homologous recombination during meiosis and base mismatch repair so that one allele gets converted to another allele
Differentiation
Process by which a cell undergoes a change to an overtly specialized cell type
Chromosome condensation
Process by which a chromosome becomes packed up into a more compact structure previous to M phase of the cell cycle
Exocytosis
Process by which most molecules are secreted from an eukaryotic cell. These molecules are packaged in membrane-bounded vesicles that fuse with the plasma membrane, releasing their contents to the outside https://o.quizlet.com/i/nKuCuNsXZjgJcEp-UxSYVQ_m.jpg
Phagocytosis
Process by which particulate material is endocytosed ("eaten") by a cell. Prominent in carnivorous cells, such as Amoeba proteus, and in vertebrate macrophages and neutrophils.
Carbon fixation
Process by which plants incorporate atmospheric carbon into carbohydrates
Photosynthesis
Process by which plants, algae and some bacteria use the energy of sunlight to drive the synthesis of organic molecules from carbon dioxide and water.
Translation (RNA translation)
Process by which the sequence of nucleotides in a messenger RNA molecule directs the incorporation of amino acids into protein. It occurs on a ribosome.
Oxidative phosphorylation
Process in bacteria and mitochondria in which ATP formation is driven by the transfer of electrons from food molecules to molecular oxygen. Involves the intermediate generation of a pH gradient across a membrane and chemiosmotic coupling
Recombination
Process in which DNA molecules are broken and the fragments are rejoined in new combinations. Can occur in the living cell-for example, through crossing-over during meiosis-or in vitro using purified DNA and enzymes that break and ligate DNA strands.
RNA splicing
Process in which intron sequences are excised from RNA transcripts in the nucleus during formation of messenger and other RNAs.
Cell fusion
Process in which the plasma membranes of two cells fuse down at the point of contact, allowing cytoplasms to mingle
Aerobic
Process that requires or occurs in the presence of O2
Capacitation
Process that sperm must undergo in the female reproductive tract before they are competent for fertilization
Acrosome reaction
Process that takes place when the sperm's head releases hydrolytic enzymes to penetrate the zona pellucida
Constitutive
Produced in constant amount. Opposite of regulated.
immortalization
Production of a cell line capable of an unlimited number of cell divisions. Can be the result of a chemical or viral transformation or of fusion of the original cells with cells of a tumor line
RNA editing
Production of a functional mRNA by insertion or alteration of individual nucleotides in an RNA molecule after it is synthesized.
Parthenogenesis
Production of a new individual from an egg cell in the absence of fertilization by sperm. Component process of apomixis
Alternative RNA splicing
Production of alternative transcripts which will get translated into different proteins by the inclusion or exclusion of exons from a pre-mRNA
Apoptosis
Programmed cell death in which a "suicide" program leads to fragmentation of DNA, shrinkage of the cytoplasm, membrane changes and cell death without lysis or damage to neighboring cells https://o.quizlet.com/3VPZQd5RQsb7g5OubGQavw_m.png
Affinity maturation
Progressive increase in the affinity of antibodies for the immunizing antigen with the passage of time after immunization
Nucleus
Prominent membrane-bounded organelles in a eukaryotic cell, containing DNA organized in chromosomes
Capsid
Protein coat of a virus formed by self-assembly of one or more protein subunits into a geometrical structure
Heterodimer
Protein complex composed of two different polypeptide chains
Gamma-tubulin ring complex
Protein complex containing gamma-tubulin and other proteins that is an efficient nucleator of microtubules https://o.quizlet.com/DHVBONymoRk3BVQrI5sh9g_m.jpg
ARP complex
Protein complex tat nucleates actin filament growth form the (-) end https://o.quizlet.com/EBSpc7vumQF-z.WabrG8fQ_m.png
Cyclin-Cdk complex
Protein complexes that are formed periodically during the eukaryotic cell cycle as the level of cyclin increases, and in which the cyclin dependent kinase (Cdk) becomes partially activated
Pleckstrin homology domain (PH domain)
Protein domain found in intracellular signaling proteins by which they bind to inositol phospholipids phosphorylated by PI 3-kinase.
Actin
Protein found as a monomer G-actin (globular) or as a polymer of F-actin (filamentous) in microfilaments. Essential for mobility and contraction of cells in cell division.
Integral membrane protein
Protein held tightly in a membrane. Can only be removed by treatments that disrupt the lipid bilayer
cyclic AMP-dependent protein kinase
Protein kinase A. Enzyme that phosphorylates target proteins in response to a rise in intracellular cAMP
Cyclin-dependent kinase
Protein kinase that has to be complexed with a cyclin in order to act. By phosphorylating different target proteins they trigger different steps in the cell division cycle
Cdk activating kinase
Protein kinase that phosphorylates and activates Cdks in cyclin-cdk complexes
Ca2+/calmodulin-dependent protein kinase
Protein kinase whose activity is regulated by Ca2+ activated calmodulin and which indirectly mediates the effects of Ca2+ by phosphorylation of other proteins
Cell adhesion molecule
Protein on the surface of an animal cell that mediates cell-cell binding or cell-matrix binding
Antibody
Protein produced by B cells in response to a foreign molecule/cell to which is binds, activating it or marking it for destruction by phagocytosis or complement-induced lysis https://o.quizlet.com/i/KxEGnltl6gcFo8KVO76w5Q_m.jpg
Elongation factor
Protein required for the addition of amino acids to growing polypeptide chains on ribosomes
Signal patch
Protein sorting signal that consists of a specific three-dimensional arrangement of atoms on the folded protein's surface.
Nuclear lamin
Protein subunit of the intermediate filaments of the nuclear lamina
Clathrin
Protein that assembles into a polyhedral cage on the cytosolic side of a membrane, which buds off by endocytosis to form a coated vesicle
Ankryin
Protein that attaches spectrin-actin cytoskeleton to plasma membranes (anchor)
Adaptin
Protein that binds CLATHRIN to the membrane surface in clathrin-coated vesicles https://o.quizlet.com/HA5N6YqHSLsmisobDYgsPQ_m.jpg
Receptor
Protein that binds a specific extracellular signal molecule (ligand) and initiates a response in the cell. Cell-surface receptors, such as the acetylcholine receptor and the insulin receptor, are located in the plasma membrane, with their ligand-binding site exposed to the external medium. Intracellular receptors, such as steroid hormone receptors, bind ligands that diffuse into the cell across the plasma membrane.
Lectin
Protein that binds tightly to a specific sugar. Abundant from plant seeds are often used as assiduity reagents to purify glycoproteins or to deter them on the cell surface
Guanine Nucleotide Exchange Factor
Protein that binds to a GTP-binding protein and activates it by stimulating it to release its tightly bound GDP; thereby allowing it to bind GTP in its place
GTPase-activating protein
Protein that binds to a GTP-binding protein and inactivates it by stimulating its GTPase activity so that it hydrolyzes its bound GTP to GDP https://o.quizlet.com/ZUspvT2BtteoKHxEe-at9w_m.png
Repressor
Protein that binds to a specific region of DNA to prevent transcription of an adjacent gene.
Cdk inhibitor protein
Protein that binds to and inhibits cyclin-Cdk complexes, involved in control of G1 and S phase
Single-strand DNA-binding protein
Protein that binds to the single strands of the opened-up DNA double helix, preventing helical structures from reforming while the DNA is being replicated.
Enzyme
Protein that catalyzed a specific chemical reaction
Allosteric protein
Protein that changes its activity when its conformation is modified
Chaperone
Protein that helps other proteins avoid misfolding, which produces inactive or aggregated polypeptides
Cohesin
Protein that holds together sister chromatids along their length before their separation
Peripheral membrane protein
Protein that is attached to one face of a membrane by noncovalent interactions with other membrane proteins, and which can be removed by relatively gentle treatments that leave the lipid bilayer intact.
Membrane protein
Protein that is normally closely associated with a cell membrane
Scaffold protein
Protein that organizes groups of interacting intracellular signaling proteins into signaling complexes.
Cyclin
Protein that periodically rises and falls in concentration in step with the eukaryotic cell cycle. It activates crucial protein kinases and helps control progression from one stage of the cell cycle to the next
Initiation factor
Protein that promotes the proper association of ribosomes with messenger RNA and is required for the initiation of protein synthesis
ER resident protein
Protein that remains in the ER or its membranes and carried out its function there, as opposed to other that are only in transit
Motor protein
Protein that uses energy derived from nucleoside triphosphate hydrolysis to propel itself along a protein filament or another polymeric molecule
TIM complexes
Protein translocators in the mitochondrial inner membrane. The TIM23 complex mediates the transport of proteins into the matrix and the insertion of some proteins into the inner membrane; the TIM22 complex mediates the insertion of a subgroup of proteins into the inner membrane.
NSF
Protein with ATPase activity that disassembles a complex of a v-SNARE and a t-SNARE
GTP-binding protein
Protein with GTPase activity that binds GTP, which activates the protein. The intrinsic GTPase activity eventually converts the GTP to GDP which inactivates the protein. These GTPases act as molecular switches in intracellular signaling pathways
Mcm proteins
Proteins in the eukaryotic cell that bind to origin recognition complexes in DNA in early G1 and are involved in forming pre-replicative complex https://o.quizlet.com/i5HDxgPcwQBa5uxZn.01eQ_m.png
Adaptor protein
Proteins that link different proteins together in intracellular pathways
Cadherin
Proteins that mediate Ca2+ dependent cell-cell adhesion in animal tissues https://o.quizlet.com/i/KX6rZ9H1QjDCWp3Hn8rThA_m.jpg
Actin-binding protein
Proteins that modifies G- or F-actin's properties (e.g. myosin)
Nernst equation
Quantitative expression that relates the equilibrium ratio of CONCENTRATION of an ION on either side of a permeable membrane to the VOLTAGE difference across the membrane
Antisense RNA
RNA complementary to a specific RNA transcript that hybridizes to it and blocks the RNA's gene function https://o.quizlet.com/jgoPHT2gZhFgm5GEjnDdcA_m.png
Messenger RNA
RNA molecule that specifies the amino acid sequence of a protein. Produced by RNA splicing from a larger RNA molecule in eukaryotes, made by RNA polymerase as a complementary copy of DNA. Translated into a protein in a process catalyzed by ribosomes
Nucleic acid
RNA or DNA, a macromolecule consisting of a chain of nucleotides joined together by phosphodiester bonds
Transcript
RNA product of DNA transcription.
Ribozyme
RNA with catalytic activity.
Retrovirus
RNA-containing virus that replicates in a cell by first making a double-stranded DNA intermediate.
Jak-STAT signaling pathway
Rapid signaling pathway by which some extracellular signals activate gene expression. Involves cell-surface receptor and cytoplasmic Jaks plus signals transducers and activator of transcription (STATs) https://o.quizlet.com/JBuLHmbDYb-BfJqyCx.q1w_m.png
Mutation rate
Rate at which observable changes occur in a DNA sequence
Equilibrium constant (k)
Ratio of forward and reverse rate constant for a reaction and equal to the association constant
Phosphorylation
Reaction in which a phosphate group becomes covalently coupled to another molecule.
Epimerization
Reaction that alters the steric arrangement around one atom, as in a sugar molecule
Autocatalysis
Reaction that is catalyzed by one of its products, creating a positive feedback effect on the reaction rate
V(D)J joining
Recombination process by which gene segments are brought together to form a functional gene for a polypeptide chain of an immunoglobulin or T cell receptor.
General recombination
Recombination that takes place between two homologous chromosomes
FADH2
Reduced flavin adenine dinucleotide. activated carrier molecule that is produced by the citric acid cycle
Supercoiled DNA
Region of DNA in which the double helix is further twisted on itself.
Structural gene
Region of DNA that codes for a protein or for an RNA molecule that forms part of a structure or has an enzymatic function. Distinguished from regions of DNA that regulate gene expression.
Gene
Region of DNA that controls a discrete hereditary characteristic, usually corresponding to a single protein or RNA. It includes coding DNA sequences, non coding regulatory sequences and introns
Nucleolar organizer
Region of a chromosome containing a cluster of ribosomal RNA genes that gives rise to a nucleolus
Heterochromatin
Region of a chromosome that remains highly condensed, transcriptionally inactive during interphase
Active site
Region of an enzyme that interacts with its substrate in order to catalyze a reaction
Variable region
Region of an immunoglobulin light of heavy chain that differs from molecule to molecule; it comprises the antigen-binding site.
Clathrin-coated pit
Region of plasma membrane of animal cells that is coated with clathrin on its cytosolic face. Such regions are continually forming and budding of by endocytosis to form intracellular clathrin-coated vesicles containing extracellular fluid and materials dissolved in it
Smooth endoplasmic reticulum (smooth ER)
Region of the endoplasmic reticulum not associated with ribosomes. It is involved in lipid synthesis.
Binding site
Region on the surface of one molecule that can interact with another molecule through non covalent bonding
Compartment
Regions in the embryo that are formed exclusively from the descendants of a few founder cells. No cell movement between them once these are delimited
Satellite DNA
Regions of highly repetitive DNA from a eukaryotic chromosome, usually identifiable by its unusual nucleotide composition. Satellite DNA is not transcribed and has no known function.
Secondary structure
Regular local folding pattern of a polymeric molecule. In proteins, alpha helices and beta sheets.
Enhancer
Regulatory DNA sequence to which transcription factors bind, influencing the rate of transcription of a gene that can be a thousand of base pairs away (upstream of downstream). It folds in a loop so TFs can interact with a specific promoter
Respiratory control
Regulatory mechanism that controls the rate of electron transport in the respiratory chain according to need via a direct influence of the electrochemical proton gradient.
Antiparallel
Relative orientation of two DNA strands in a double helix. The polarity of one strand is oriented in the opposite direction to that of the other
Stem cell
Relatively undifferentiated cell that can continue dividing indefinitely, throwing off daughter cells that can undergo terminal differentiation into particular cell types.
Signal transduction
Relaying of a signal by conversion from one physical or chemical form to another. In cell biology, the process by which a cell converts an extracellular signal into a response.
Ovulation
Release of an egg from the ovary
Sarcomere
Repeating unit of a myofibril in a muscle cell, composed of an array of overlapping thick (myosin) and thin (actin) filaments between two adjacent Z discs.
Cell cycle
Reproductive cycle of a cell. The orderly sequence of events by which a cell duplicates its contents and divides into two.
Nuclear Magnetic Resonance NMR
Resonant absorption of electromagnetic radiation at a specific frequency by atomic nuclei in a magnetic field, due to flipping of the orientation of their magnetic dipole moment. Provides information about the chemical environment of the nuclei. 2D is used to determine the 3D structure of proteins
Immune response
Response made by the immune system when a foreign substance or microorganism enters its body
Adaptive immune system
Response of immune system to a specific antigen that generates immunological memory
Signal-recognition particle (SRP)
Ribonucleoprotein particle that binds an ER signal sequence on a partially synthesized polypeptide chain and directs the polypeptide and its attached ribosome to the endoplasmic reticulum.
Membrane-bound ribosome
Ribosome attached to the cytosolic face of the endoplasmic reticulum. Site of synthesis of proteins that enter the ER
Free ribosome
Ribosome that is free in the cytosol, unattached to any membrane. It is the site of synthesis of all proteins encoded by the nuclear genome other than those destined to enter the ER. It produces proteins and releases it in the cytosol and used within the cell
Contractile ring
Ring containing actin and myosin that forms under the surface of animal cells undergoing cell division and contracts to pinch the two daughter cells apart https://o.quizlet.com/kDrxZ6ZMZS5iuahcMw94kA_m.png
Lysis
Rupture of a cell's membrane, leading to the release of cytoplasm and the death of the cell
Acrosomal vesicle
Sac of hydrolytic enzymes found in the sperm's head used to digest the egg's coat (ákros, "highest, at the extremity" and sôma, "body")
Genomics
Science of studying DNA sequences and properties of entire genomes
Zygotene
Second stage of division I meiosis, in which the synaptonemal complex begins to form between the two sets of sister chromatids in each bivalent chromosome.
Alpha helix
Secondary protein structure in which a linear sequence of amino acids folds into a right-handed helix stabilized by internal hydrogen bonding
Interleukin
Secreted peptide or protein that mainly mediates local interactions between white blood cells during inflammation and immune responses
Local mediator
Secreted signal molecule that acts at short range on adjacent cells
Immature secretory vesicle
Secretory vesicle that appears to have just pinched off the Golgi stack. Its structure resembles that of a cisterna of the trans Golgi network
Transposable element (Transposon)
Segment of DNA that can move from one position in a genome to another.
Exon
Segment of an eukaryotic gene that consists of a DNA sequence that will be represented in mRNA, tRNA or rRNA after splicing of introns has occurred.
RNA interface (RNAi)
Selective intracellular degradation of RNA that is intended to remove foreign RNAs, such as those of viruses. Fragments cleaved from free double-stranded RNA direct the degradative mechanism to other similar RNA sequences. Widely exploited in a technique used to silence the expression of selected genes.
Cell division
Separation of a cell into two daughter cells. In eukaryotes it entails the division of the nucleus followed by cytokinesis (division of the cytoplasm)
Primary structure
Sequence of monomer units in a linear polymer, such as the amino acid sequence of a protein.
Codon
Sequence of three nucleotides in a DNA or messenger RNA that represents the instruction of incorporation of a specific amino acid into a polypeptide chain during translation
Electron-transport chain
Series of electron carrier molecules that move electrons from a higher to a lower energy level to a final acceptor molecule (e.g. oxygen). The energy released during electron movement can be used to power various processes. In inner mitochondrial membrane and in thylakoid membrane of chloroplasts, generate a proton gradient across the membrane that is used to drive ATP synthesis
Phosphodiester linkage
Set of covalent chemical bonds formed when two hydroxyl groups are linked in ester linkage to the same phosphate group. This linkage joins adjacent nucleotides in RNA or DNA.
Chemical group
Set of covalently linked atoms (-OH, -NH2)
Genetic code
Set of rules specifying the correspondence between nucleotide triplets (codons) in DNA or DNA and amino acids in proteins
Transfer RNA (tRNA)
Set of small RNA molecules used in protein synthesis as an interface (adaptor) between messenger RNA and amino acids. Each type of tRNA molecule is covalently linked to a particular amino acid.
ER retention signal
Short amino acid sequence on a protein that prevents it moving out of the ER, found on ER resident proteins
Start-transfer signal
Short amino acid sequence that enables a polypeptide chain to start being translocated across the endoplasmic reticulum membrane through a protein translocator. Multipass membrane proteins have both N-terminal (signal sequence) and internal start-transfer signals.
Signal sequence
Short continuous sequence of amino acids that determines the eventual location of a protein in the cell. An example is the N-terminal sequence of 20 or so amino acids that directs nascent secretory and transmembrane proteins to the endoplasmic reticulum.
Basal body
Short cylindrical array of microtubules plus their associated proteins found at the base of eukaryotic cell cilia/flagella. Similar to a centriole.
Centriole
Short cylindrical array of microtubules, similar to a basal body. In animal cells, a pair is found at the center of a centrosome.
Okazaki fragments
Short lengths of DNA produced on the lagging strand during DNA replication. Rapidly joined by DNA ligase to form a continuos DNA strand
Oligosaccharide
Short linear or branched chain of covalently linked sugars
Oligomer
Short polymer, in the cell they could consist of amino acids, sugars, or nucleotides (greeks oligos, few)
Operator
Short region of DNA in a bacterial chromosome that controls the transcription of an adjacent gene
RNA primer
Short stretch of RNA synthesized on a DNA template. It is required by DNA polymerase to start their DNA synthesis.
Homeobox
Short, 180 bp long, conserved DNA sequence that encodes a DNA-binding protein motif (homeodomain) famous for its presence in genes involved in orchestrating development in a wide range of organisms
Paracrine signaling
Short-range cell-cell communication via secreted signal molecules that act on adjacent cells
Fission yeast
Shqzosaccharomyces bombe. Unicellular rod-shaped eukaryote used as a model organism in cell and molecular biology (e.g. cell cycle regulation and division)
Terminator
Signal in bacterial DNA that halts transcription.
Plant growth regulator
Signal molecule (also known as a plant hormone) that helps coordinate growth and development. Examples are ethylene, auxins, gibberellins, cytokines, abscisic acid, and the brassinosteroids.
Hormone
Signal molecule secreted by an endocrine cell into the bloodstream, which can carry it to distant target cells
Morphogen
Signal molecule that can impose a pattern on a field of cells by causing cells in different places to adopt different fates
Nuclear localization signal
Signal sequences found in proteins destined for the nucleus and which enable their selective transport into the nucleus from the cytosol through the nuclear pore complexes
Monosaccharide
Simple sugar with the general formula (CH20)n
Prokaryote
Single-celled microorganism whose cells lack a well-defined, membrane-enclosed nucleus. The prokaryotes comprise two of the major domains of living organisms-the Bacteria and Archaea.
X-inactivation center (XIC)
Site in an X chromosome at which inactivation is initiated and spreads outwards.
Regulatory site
Site on an enzyme, other than the active site, that binds a molecule that affects enzyme activity.
Basal
Situated near the base.
Ventral
Situated toward the belly surface of an animal, or towards the underside of a wing or leaf.
Posterior
Situated toward the tail end of the body.
Anterior
Situated towards the head end of the body https://o.quizlet.com/i/J1yYXwLGzooKMD8-KIlWoA_m.jpg
Genomic imprinting
Situation where a gene is either expressed or not expressed in the embryo depending on which parent it is inherited from
Cloning vector
Small DNA molecule usually derived from a bacteriophage or plasmid, which is used to carry a DNA fragment to be cloned into a recipient cell and which allows this to be replicated
Small nuclear RNA (snRNA)
Small RNA molecules that are complexed with proteins to form the ribonucleoprotein particles involved in RNA splicing.
Sugar
Small carbohydrates with a monomer unit of general formula (CH2O)n. Examples are the monosaccharides glucose, fructose, and mannose; and the disaccharide sucrose (composed of a molecule of a molecule of glucose and one of fructose linked together).
Plasmid
Small circular DNA molecule that replicates independently of the genome. Modified plasmids are used extensively as plasmid vectors for DNA cloning.
Activated carrier - Coenzyme
Small diffusible molecule in the cell that stores energy in the form of covalent bonds. ATP, NADPH
Ionophore
Small hydrophobic molecule that dissolves in lipid bilayers and increases their permeability to specific inorganic ions https://o.quizlet.com/5p8fxUOLITALEqugmVcMBg_m.png
Peroxisome
Small membrane-bounded organelle that uses molecular oxygen to oxidize organic molecules. Contains some enzymes that produce and others that degrade hydrogen peroxide (H2O2).
Coated vesicle
Small membrane-bounded organelle with a cage of proteins (coat) on its cytosolic surface. Formed by the pinching off of a coated region or membrane.
Monomer
Small molecular building block that can serve as a subunit, being linked to others of the same type to form a polymer
Coenzyme
Small molecule associated with an enzyme that participates in the reaction catalyzed by the enzyme, often by forming a covalent bond with the substrate
Second messenger
Small molecule that is formed in or released into the cytosol in response to an extracellular signal and helps to relay the signal to the interior of the cell. Examples include cAMP, IP3, and CA2+.
Coenzyme A
Small molecule used in the enzymatic transfer of acetyl groups in the cell
Synaptic vesicle
Small neurotransmitter-filled secretory vesicle formed at the axon terminals of nerve cells and whose contents are released into the synaptic cleft by exocytosis when an action potential reaches the axon terminal.
Glycerol
Small organic molecule that is the parent compound of many small molecules in the cell (e.g. phospholipids) https://o.quizlet.com/i/9MyJ6S-LnCc-YwgN76J80Q_m.jpg
Glutaraldehyde
Small reactive molecule with two aldehyde groups that is often used as a cross-linking fixative https://o.quizlet.com/i/RjNLwAeZ0Q1VfNLTGCRbQA_m.jpg
Lipid raft
Small region of plasma membrane enriched in sphingolipids and cholesterol https://o.quizlet.com/SAkmufpNfTFJZhjVN5FvYg_m.png
Chemokine
Small secreted protein that attracts cells to move towards its source (white blood cells in immune system)
cyclic GMP
Small soluble intracellular signaling molecule formed from GTP by enzyme guanylyl cyclase in response to photoreceptor stimulation in the retina
Microsome
Small vesicle that is derived from fragmented endoplasmic reticulum produced when cells are homogenized
Erythrocyte
Small, hemoglobin containing red blood cell of vertebrates that transports O2 and CO2 to an from tissues
Ubiquitin
Small, highly conserved protein present in all eukaryotic cells that becomes covalently attached to lysines of other proteins. Attachment of a short chain of ubiquitins to such a lysine tags a protein for intracellular proteolytic destruction by a proteasome.
Quinone
Small, lipid soluble, mobile electron carrier molecule found in the respiratory and photosynthetic electron-transport chains.
Vesicle
Small, membrane-bounded, spherical organelle in the cytoplasm of a eukaryotic cell.
Substratum
Solid surface to which a cell adheres.
Nuclear export signal
Sorting signal contained in the structure of molecules and complexes, such as RNA and new ribosomal subunits, that are transported from the nucleus to the cytosol through nuclear pore complexes
Conformation
Spatial arrangement of atoms in three dimensions in a macromolecule
Initiator tRNA
Special tRNA that initiates translation. Always carries the amino acid methionine
Meiosis
Special the o cell division by which eggs and sperm cells are produced. Comprises two successive nuclear divisions with only one round of dan replication, and produces four haploid daughter cells from an initial diploid cell
Hemidesmosome
Specialized anchoring cell junction between an epithelial cell and the underlying basal lamina
Endocrine cell
Specialized animal cell that secretes a hormone into the blood. Usually part of a gland, such as thyroid or pituitary gland
Neuromuscular junction
Specialized chemical synapse between an axon terminal of a motor neuron and a skeletal muscle cell
Cardiac muscle
Specialized form of striated muscle found in the heart, consisting of individual heart muscle cells linked together by cell junctions
Gamete
Specialized haploid cell, either a sperm or an egg, that will fuse for fertilization and thus sexual reproduction to occur
Cell cortex
Specialized layer of cytoplasm on the inner face of plasma membrane. In animal cells it is an actin-rich layer responsible for movement of the cell surface
Cell junction
Specialized region of connection between two cells or between a cell and the extracellular matrix
Cortical granule
Specialized secretory vesicle present under the plasma membrane of unfertilized eggs. It prevents the entry of further sperm after fertilization. https://o.quizlet.com/VV7LFtDqJTtv1LxG3UAEVw_m.png
Spemann's Organizer
Specialized tissue at the dorsal lip of the blastopore in an amphibian embryo; a source of signals that help to orchestrate formation of the embryonic body axis.
Xenopus laevis (South African Clawed Toad)
Species of frog (not toad) frequently used in studies of early vertebrate development.
Drosophila melanogaster
Species of small fly, commonly called a fruit fly, much used in genetic studies of development
Antigenic determinant - Epitope
Specific region of an antigen that binds to an antibody https://o.quizlet.com/2rYoyiYbvfnpPjNYrljwJQ_m.png
Metastasis
Spread of cancer cells from their site of origin to other sites in the body
SH2 domain
Src homology region 2, a protein domain present in many signaling proteins; it binds a short amino acid sequence containing a phosphotyrosine.
Covalent bond
Stable chemical link between two atoms produced by sharing one or more electron pairs
Grana
Stacked membrane discs (thylakoids) in chloroplasts that contain chlorophyll and are the site of the light-trapping reactions of photosynthesis https://o.quizlet.com/i5pyNJIf3Zh8CAiob07xVw_m.jpg
Metaphase
Stage of mitosis at which chromosomes are firmly attached to the mitotic spindle at its equator but have not yet segregated toward opposite poles
Anaphase
Stage of mitosis during which the two sets of chromosomes separate and move away from each other https://o.quizlet.com/ojh0DqDk1nsPLIrYSGF2jQ_m.jpg
Negative staining
Staining technique in electron microscopy in which a reverse, negative, image of the object is created
Dideoxy method
Standard Sanger Sequencing method
Kilojoule
Standard unit of energy equal to 1000 joules
Joule
Standard unit of energy. Energy delivered in one second by one-watt power source. Equal to 0.24 calories
Aster
Star-shaped system of microtubules emanating from a centrosome or from a pole of a mitotic spindle https://o.quizlet.com/HXki0JCU2MnfdkwAXbtACA_m.jpg
Lysogeny
State of a bacterium in which it carries the DNA of an inactive virus integrated into its genome. The virus can subsequently be activated to replicate and lyse the cell
G0
State of withdrawal from the eukaryotic cell division cycle by entry into a quiescent G1 phase. Common state for differentiated cells
Equilibrium
State where there is no net change in a system (e.g. in a chemical reaction when the forward and reverse rates are equal)
Notochord
Stiff rod of mesoderm that runs along the back of all chordate embryos. It does not persist and becomes incorporated into the vertebral column
Bond energy
Strength of the chemical linkage between two atoms measured in kilocalories or kilojoules needed to break it
Heat Shock Protein
Stress-response protein. Protein synthesized in increased amounts in response to an elevated temperature and which usually helps the cell to survive the stress. hsp60, hsp70
Leucine zipper
Structural motif seen in many DNA-binding proteins in which two alpha helices from separate proteins are joined together in a coiled-coil (zipper), forming a protein dimer
Cellulose
Structural polysaccharide consisting of long hairs of covalently linked glucose units. Provides tensile strength in plant cell walls
Beta sheet
Structural protein motif in which different sections of a polypeptide chain run alongside each other joined by hydrogen bonds between atoms in the polypeptide backbone https://o.quizlet.com/TodSHr4iwXygLRAjUcKv4A_m.jpg
Midbody
Structure formed at the end of cleavage that can persist for some time as a tether between the two daughter cells in animals
Phragmoplast
Structure made of microtubules and actin filaments that forms in the prospective plane of division of a plant cell and guides formation of the cell plate.
Transition state
Structure that forms transiently in the course of a chemical reaction and has the highest free energy of any reaction intermediate. Its formation is a rate-limiting step in the reaction.
Synaptonemal complex
Structure that holds paired chromosomes together during prophase I of meiosis and promotes genetic recombination.
Base
Substance that can accept protons in solution. E.g. pyrimidines and purines
Catalyst
Substance that can lower the activation energy of a reaction by increasing its rate
Acid
Substance that donates PROTONS when in water (hydronium ion H3O+)
Antibiotic
Substance toxic to microorganisms
Development
Succession of changes that take place in an organism as a fertilized egg gives rise to an adult
Carbohydrate
Sugars or related compounds containing (CH2O)n
Glial cell
Supporting cell of the nervous system, including oligodendrocytes and astrocytes in the vertebrate central nervous system and Schwann cells in the peripheral nervous system https://o.quizlet.com/jXCbnt7EhS3v6vGWrc1MCg_m.png
Nonsense mediated mRNA decay
Surveillance pathway that exists in all eukaryotes, Its main function is to reduce errors in gene expression by eliminating mRNA transcripts that contain premature stop codons. Translation of these aberrant mRNAs could, in some cases, lead to deleterious gain-of-function or dominant-negative activity of the resulting proteins
Anabolism
System of biosynthetic reactions in a cell by which LARGE molecules are made from SMALLER ones.
Cytoskeleton
System of protein filaments in the cytoplasm of eukayortic cells that gives the cell shape and capacity for directed movement. Made of Actin filaments, microtubules and intermediate filaments https://o.quizlet.com/i/e6uic2G9RYXhymRnI-mICw_m.jpg
Complement system
System of serum proteins activated by antibody-antigen complexes or microorganisms. Helps eliminate pathogens by causing their lysis or promoting phagocytosis
Cytotoxic T cell
T cell responsible for killing infected cells
Adenomatous polyposis coli (APC)
TUMOR SUPRESSOR protein (recruits free cytoplasmic beta catenin and degrades it)
Site-directed mutagenesis
Technique by which a mutation can be made at a particular site in DNA.
Western blotting
Technique by which proteins are separated by electrophoresis and immobilized on a paper sheet and then analyzed, usually by means of a labeled antibody.
Polymerase Chain Reaction
Technique for amplifying a specific region of DNA by the use of sequence specific primers and multiple cycles of DNA synthesis, each cycle being followed by a brief heat treatment to separate complementary strands
Polymerase chain reaction (PCR)
Technique for amplifying specific regions of DNA by the use of sequence-specific primers and multiple cycles of DNA synthesis, each cycle being followed by a brief heat treatment to separate complementary strands.
Phage display
Technique for detecting proteins that interact with each other by screening a protein against a library of genetically modified phage, each displaying a potential binding protein on their surface.
DNA footprinting
Technique for determining the DNA sequence to which a DNA-binding protein binds
X-ray crystallography
Technique for determining the three-dimensional arrangement of atoms in a molecule based on the diffraction pattern of X-rays passing through a crystal of the molecule.
Pulse-chase
Technique for following the movement of a substance through a biochemical or cellular pathway, by briefly adding the radioactively labeled substance (the pulse) followed by the unlabeled substance (the chase).
Two-hybrid system
Technique for identifying interacting proteins using genetically engineered yeast cells.
DNA affinity chromatography
Technique for purifying sequence-specific DNA-binding proteins by their binding to a matrix to which the appropriate DNA fragments are attached
Freeze fracture electron microscopy
Technique for studying membrane structure, in which the membrane of a frozen cell if fractured along the interior of the bilayer separating it into the two monolayers with the interior faces exposed
Southern blotting
Technique in which DNA fragments separated by electrophoresis are immobilized on a paper sheet. Specific fragments are then detected with a labeled nucleic acid probe.
Northern blotting
Technique in which RNA fragments separated by electrophoresis are immobilized on a paper sheet. A specific RNA is then detected by hybridization with a labeled nucleic acid probe
Autoradiography
Technique in which a radioactive object produces an image of itself on a photographic film.
in situ hybridization
Technique in which a single-stranded RNA or DNA probe is used to locate a gene or a messenger RNA molecule to a cell or tissue by hybridization
DNA microarray
Technique than detects the simultaneous expression of a large number of genes in cells, in which isolated cellular mRNAs is hybridized to a large array of short DNA probes immobilized on glass slides
Fluorescent resonance energy transfer (FRET)
Technique used to monitor the distance between two fluorescently labeled molecules (and thus their interaction) in cells
Transcription factor
Term loosely applied to any protein required to initiate or regulate transcription in eukaryotes. Includes both gene regulatory proteins as well as the general transcription factors.
in vitro
Term used to describe a process taking place in an isolated cell-free extract or cells growing in culture as opposed to in an organism (latin for in glass)
Selectivity filter
That part of an ion channel structure that determines which ions it can transport.
Double helix
The 3D structure of DNA in which two DNA chains are held together by hydrogen bonds between the bases and wound into each other
Redox potential
The affinity of a redox pair for electrons, generally measured as the voltage difference between an equimolar mixture of the pair and a standard reference. NADH/NAD+ has a low redox potential and O2/H2 has a high redox potential (high affinity for electrons).
Polypeptide backbone
The chain of repeating carbon and nitrogen atoms, linked by peptide bonds, in a polypetide or protein. The side chains of the amino acids project from this backbone.
Electrochemical gradient
The concentration difference of an ion between the two sides of a membrane and the electrical charge across it (membrane potential), which forces the ion to move across the membrane by a driving force
Combinatorial control
The control of a step in a cellular process by a combination of proteins
Protein phosphorylation
The covalent addition of a phosphate group to a side chain of a protein catalyzed by a protein kinase.
Oocyte
The developing egg. It is usually a large and immobile cell
Vegetal pole
The end at which most of the yolk is located in an animal egg. The end opposite the animal pole.
Plus end
The end of a microtubule or actin filament at which addition of monomers occurs most readily; the "fast-growing" end of a microtubule or actin filament. The plus end of an actin filament is also known as the barbed end.
Minus end
The end of a microtubule or actin filament at which the addition of monomers occurs lead readily; the "slow growing" end of the microtubule or actin filament. Aka pointed end
Post-translational modification
The enzyme-catalyzed change to a protein made after it is synthesized. Examples are acetylation, cleavage, glycosylation, methylation, phosphorylation, and prenylation.
Allelic exclusion
The expression of only one allele while the other allele is silenced (through transcriptional or post transcriptional gene silencing) (Ig)
Heavy chain
The larger of the two types of polypeptides in an immunoglobulin molecule https://o.quizlet.com/Hf6mEulU9-Jjsc3d.Myevw_m.jpg
Germ line
The lineage of germ cells (which contribute to the formation of a new generation of organisms), as distinct from somatic cells (which form the body and leave no descendants)
Membrane
The lipid bilayer plus associated proteins that encloses al cells and in eukaryotic cells, many organelles as well
Phospholipid
The main category of lipid molecules used to construct biological membranes. Generally composed of two fatty acids linked through glycerol phosphate to one of a variety of polar groups.
Protein
The major macromolecular constituent of cells. A linear polymer of amino acids linked together by peptide bonds in a specific sequence.
Hemoglobin
The major protein in red blood cells that associates with O2 in the lungs by means of a bound heme group
Egg
The mature female gamete in sexually reproducing organisms. Usually a large and immobile cell
Sperm
The mature male gamete in animals. It is motile and usually small compound with the egg.
Resting membrane potential
The membrane potential in equilibrium conditions in which there is no net flow of ions across the plasma membrane.
Ras protein
The most famous member of a large family of GTP-binding proteins (called monomeric GTPases) that help relay signals from cell-surface receptors to the nucleus. Named for the ras gene, first identified in viruses that cause rat sarcomas.
Transposition (cut-and-paste transposition)
The movement of a DNA sequence from one site to another within the genome
Nitrogen cycle
The natural circulation of nitrogen between molecular nitrogen in the atmosphere, inorganic molecules in the soil, and organic molecules in living organisms
Ploidy
The number of complete sets of chromosomes in a genome. Diploid organisms have two sets in their somatic cells, polyploid organisms more than two. Natural polyploidy is the result of previous duplications of the whole genome or the introduction of complete genomes from another species during evolution.
Phenotype
The observable character of a cell or organism.
Outer nuclear membrane
The outermost of the two nuclear membranes. Continuous with the ER and is studded with ribosomes on its cytosolic face
Isoelectric point
The pH at which a charged molecule in solution has no net electric charge and therefore does not move in an electric field
Photochemical reaction center
The part of a photosystem that converts light energy into chemical energy.
Side chain
The part of an amino acid that differs between different amino acids, giving the amino acid its unique physical and chemical properties.
Active transport
The pass of a molecule through a membrane channel driven by energy other than the electrochemical gradient of the molecule
Reading frame
The phase in which nucleotides are read in sets of three to encode a protein. A messenger RNA molecule can be read in any one of three reading frames, only one of which will give the required protein.
Synteny
The presence in different species of regions of chromosomes with the same genes in the same order.
Treadmilling
The process by which a polymeric protein filament is maintained at constant length by addition of protein subunits at one end and loss of subunits at the other.
Tumor progression
The process by which an initial mildly disordered cell behavior gradually evolves into a full-blown cancer.
Glycosylation
The process of adding one or more sugars to a protein or lipid molecule
Hybridization
The process whereby two complementary nucleic acid strands form a double helix. Forms the basis of a powerful technique for detecting specific nucleotide sequences
Dynamic instability
The property of sudden conversion from growth to shrinkage or vice versa in a protein filament (e.g. microtubule or actin filament)
Tubulin
The protein subunit of microtubules.
RecA protein
The prototype for a class of DNA-binding proteins that catalyze synapsis of DNA strands during genetic recombination.
Electrochemical proton gradient
The result of a combined pH gradient (proton gradient) and the membrane potential
ER lumen
The space enclosed by the membrane of the endoplasmic reticulum
Gastrulation
The stage in animal embryogenesis during which the embryo is transformed from a ball of cells to a structure with a gut
Metabolism
The total sum of the chemical processes that take place in living cells
Genome
The totality of genetic information belonging to a cell or an organism; in particular the DNA that carries information
Transcytosis
The uptake of material at one face of a cell by endocytosis, its transfer across a cell in vesicles, and its discharge from another face by exocytosis.
Biosphere
The world of living organisms
Entropy
Thermodynamic quantity that measures the degree of disorder in a system (the higher, the greater the disorder)
Lipid bilayer
Thin bimolecular sheet of mainly phospholipid molecules that forms the core structure of all cell membranes. The two layers of lipid molecules are packed with their hydrophobic tails pointing inward and their hydrophilic heads outward, exposed to water
Microvillus
Thin cylindrical membrane-covered projection on the surface of an animal cell containing a core bundle of actin filaments. Present in especially large numbers on the absorptive surface of intestinal epithelial cells https://o.quizlet.com/oUuVYKLcjBtp9J1aqd21yw_m.png
Basal lamina
Thin mat of extracellular matrix that separates epithelial sheets and other types of cells. https://o.quizlet.com/40uUf1LiwG2IV.QveQaIeQ_m.jpg
Filopodium
Thin, spike-like protrusion with an actin filament core, generated on the leading edge of a migrating cell and are involved in chemosensation and locomotion
Quaternary structure
Three-dimensional relationship of the different polypeptide chains in a multisubunit protein or protein complex.
Apical
Tip of a cell, structure or organ. Exposed free surface of an epithelial cell, opposite to the basal surface https://o.quizlet.com/i/YMFzbEQXN0y6-DA5aaGn4A_m.jpg
Avidity
Total binding strength of a polyvalent antibody with a polyvalent antigen
Gene activator protein
Transcription factor. A gene regulatory protein that when bound to its regulatory sequence in DNA, activates transcription
Na+ K+ pump
Transmembrane carrier protein found in the plasma membrane of most animal cells that pumps Na+ out of and K+ into the cell, using energy derived from ATP hydrolysis
Membrane channel
Transmembrane protein complex that allows inorganic ions or other small molecules to diffuse passively across the lipid bilayer
Ion channel
Transmembrane protein complex that forms a water-filled channel across the lipid bilayer through which specific inorganic ions can diffuse down their electrochemical gradients
Integrin
Transmembrane protein involved in the adhesion of cells to the extracellular matrix and to each other
Pump
Transmembrane protein that drives the active transport of ions or small molecules across the lipid bilayer.
Notch
Transmembrane receptor protein involved in many instances of choice of cell fate. Important for cell-cell communication and cell differentiation
Prion disease
Transmissible spongiform encephalopathies such as Kreutzfeld-Jacob disease in humans, scrapie in sheep and bovine spongiform encephalopathy (BSE) in cattle, that are apparently caused and transmitted by abnormal forms of a protein (Prions).
Passive transport
Transport of a solute across a membrane down its concentration or electrochemical gradient using only the energy stored in that gradient
Vesicular transport
Transport of proteins from one cellular compartment to another by means of membrane-bounded intermediaries such as vesicles or organelle fragments.
Transcellular transport
Transport of solutes, such as nutrients, across an epithelium, by means of membrane transport proteins in the apical and basal faces of the epithelial cells.
Anticodon
Triplet of nucleotides in a tRNA molecule that is complementary to a three nucleotide sequence in an mRNA
Neural tube
Tube of ectoderm that will form the brain and spinal cord in a vertebrate embryo
p53
Tumor suppressor gene found mutated in about half of human cancers. It encodes a gene regulatory protein that is activated by DNA damage and is involved in blocking further progression through the cell cycle
Benign
Tumors that are self-limiting in growth and are noninvasive
Complementary
Two nucleic acids that can form a perfect base-paired double helix
Base pair
Two nucleotides in an RNA or DNA molecule held together by hydrogen bonds
Hox complex
Two tightly linked cluster of genes in Drosophila (bithorax and antennapedia complexes) that control the differences between the different segments of the body. Homologous Hox complexes are found in other animals, where they also determine pattern along the anteroposterior axis
van der Waals attraction
Type of (individually weak) noncovalent bond that is formed at close range between nonpolar atoms.
Multidrug resistance protein
Type of ABC transporter protein that can pump hydrophobic drugs, like anti-cancer drugs, out of the cytoplasm of eukaryotic cells
Trans-splicing
Type of RNA splicing present in a few eukaryotic organisms in which exons from two separate RNA molecules are joined together to form an mRNA.
Detergent
Type of amphipathic molecule that tends to coalesce in water, with its hydrophobic tails buried and its hydrophilic heads exposed. It is widely used to solubilize membrane proteins
Desmosome
Type of anchoring cell-cell junction usually formed between two epithelial cells, characterized by dense plaques of protein into which intermediate filaments in the two adjoining cells insert ` https://o.quizlet.com/9kD7IhhcRvTzpAqqobbwyg_m.jpg
Communicating junction
Type of cell junction that allows the passage of chemical/electrical signals from one cell to another
Anchoring junction
Type of cell junction that attaches cells to neighboring cells or extracellular matrix. Desmosons, hemidesmosons and adherent junctions.
Occluding junction
Type of cell junction that seals cells together in an epithelium, forming a barrier through which even small molecules cannot pass
Cytokine receptor
Type of cell surface receptor whose ligands are cytokines (interferons, growth hormone, prolactin) and which acts through the Jak-STAT Pathway https://o.quizlet.com/QuUzAOA46dIGx5EzRNlVnA_m.png
Helper T cell
Type of cell that helps stimulate B cells to make antibodies and activates macrophages to kill ingested microorganisms
Synaptic signaling
Type of cell-cell communication that occurs across chemical synapses in the nervous system.
Affinity chromatography
Type of chromatography that has protein-specific ligands attached to a matrix that allows for purification of a protein mixture
Fibrillar collagen
Type of collagen molecule that assembles into rope-like structures (collagens type I, II, III, V and XI)
Negative control
Type of control of gene expression in which the active DNA-binding form of the regulatory protein turns the gene off
Positive control
Type of control of gene expression in which the active DNA-binding form of the regulatory protein turns the gene on.
M-cyclin
Type of cyclin found in all eukaryotic cells that promotes mitosis
Scanning electron microscope
Type of electron microscope that produces an image of the surface of an object.
Two-dimensional gel electrophoresis
Type of electrophoresis in which the protein mixture is run first in one direction and then in a direction at right angles to the first. It enables better separation of individual proteins.
SDS polyacrylamide gel electrophoresis (SDS-PAGE)
Type of electrophoresis in which the protein mixture to be separated is run through a gel containing the detergent sodium dodecyl sulfate (SDS) which unfolds the proteins and frees them from association with other molecules.
Fluid-phase endocytosis
Type of endocytosis in which small vesicles bud off internally from the plasma membrane carrying extracellular fluid and dissolved molecules into the cell. Pinocytosis https://o.quizlet.com/cLufW8nx9Jac6VP6PMPdvw_m.png
Pinocytosis
Type of endocytosis in which soluble materials are taken up from the environment and incorporated into vesicles for digestion. Literally, "cell drinking."
Oligodendrocyte
Type of glial cell in the vertebrate central nervous system that forms a myelin sheath around axons
Neurofilament
Type of intermediate filament found in nerve cells
Voltage-gated cation channel
Type of ion channel found in the membranes of excitable cells (such as nerve cells and muscle) which opens in response to a shift in membrane potential past a threshold value.
Phase-contrast microscope
Type of light microscope that exploits the interference effects that occur when light passes through material of different refractive indexes. Used to view living cells.
Confocal microscope
Type of light microscope that uses a laser beam as a pinpoint source of illumination and scans across a plane to produce a two-dimensional optical selection
Glycosylphosphatidylinositol anchor
Type of lipid linkage by which some membrane proteins are bound to the membrane. It is formed as the proteins travel through the ER https://o.quizlet.com/8ihTVd6Wek9f6TBtOrkHNw_m.png
Smooth muscle cell
Type of long, spindle-shaped mononucleate muscle cell making up the muscular tissue found in the walls of arteries and of the intestine and other viscera, and in some other locations of the vertebrate body. Called "smooth" because it lacks the striated myofibrils of skeletal and cardiac muscle cells.
T cell (T lymphocyte)
Type of lymphocyte responsible for cell-mediated immunity; includes both cytotoxic T cells and helper T cells.
B cell
Type of lymphocyte that makes antibodies
Feedback inhibition
Type of metabolic regulation in which an enzyme acting early in a reaction pathway is inhibited by a late product of that pathway
Electron microscope
Type of microscope that uses a beam of electrons to create an image
Cut-and-paste transposition
Type of movement of a transposable element in which it is cut out of the DNA and inserted into a new site by a transposase
Translocation
Type of mutation in which a portion of one chromosome is broken off and attached to another.
Inversion
Type of mutation in which a segment of chromosome is inverted
Deletion
Type of mutation in which a single nucleotide or sequence of nucleotides has been removed from DNA
Serine protease
Type of protease that has a reactive serine in the active site.
Site-specific recombination
Type of recombination that does not require extensive similarity in the two DNA sequences undergoing recombination. Can occur between two different DNA molecules or within a single DNA molecule.
Intercalary regeneration
Type of regeneration that fills in the missing tissues when two mismatched parts of a structure and grafted together
Sexual reproduction
Type of reproduction in which the genomes of two individuals are mixed in the formation of a new organism. Individuals produced by sexual reproduction differ from either of their parents and from each other.
Asexual reproduction
Type of reproduction that produces an individual genetically identical to the parent. Does not involve gamete formation and fusion.
Histidine-kinase association receptor
Type of transmembrane receptor found in the plasma membrane of bacteria, yeast and plant cells and involved in sensing stimuli that cause bacterial chemotaxis
DNA-only transposons
Type of transposable element that exists as DNA throughout its life cycle. Many types move by cut-and-paste transposition
Retrotransposon
Type of transposable element that moves by being first transcribed into an RNA copy that is then reconverted to DNA by reverse transcriptase and inserted elsewhere in the chromosomes.
Myoepithelial cell
Type of unstriated muscle cell found in epithelia, e.g. in the iris of the ye and in glandular tissue
Lymphocyte
Type of white blood cell responsible for the specificity of adaptive immune responses. Two main types: B cells (produce antibody) and T cells (interact directly with other effector cells of the immune system and with infected cells). T cells develop in the thymus and are responsible for cell-mediated immunity. B cells develop in bone marrow and are responsible for the production of circulating antibodies
Monocyte
Type of white blood cell that leaves the bloodstream and matures into a macrophage in tissues
Acquired immunological tolerance
UNRESPONSIVENESS of the immune system to a foreign antigen
Anaphase-promoting complex (APC)
Ubiquitin ligase that promotes the destruction of a set of proteins, some of which initiate the separation of star chromatids during Metaphase-to-Anaphase transition during mitosis https://o.quizlet.com/PfndlTFXyo2hMJpxmdBLVQ_m.jpg
Calmodulin
Ubiquitous Ca2+-binding protein whose binding to other proteins is governed by changes in intracellular Ca2+ concentration. Its binding modifies the activity of many target enzymes and membrane transport proteins
Glycolysis
Ubiquitous metabolic pathway in the cytosol in which sugars are incompletely degraded with production of ATP
Neutron
Uncharged subatomic particle that forms part of an atomic nucleus
Mannose 6-phosphate
Unique marker attached to oligosaccharides on some glycoproteins destined for lysosomes
Kilocalorie
Unit of heat energy equal to 1000 calories. Used to express the energy content of food or molecules
Calorie
Unit of heat. Amount of heat needed to raise the temperature of 1 g of water by 1 C
Nanometer
Unit of length commonly used to measure molecules and cell rganeless. 10^-9 m
Angstrom
Unit of length used to measure atoms/molecules. 10-10 meter
Dalton
Unit of molecular mass. Aprox. equal to the mass of a hydrogen atom (1.66 x 10 -24 g)
Endocytosis
Uptake of material into a cell by an invagination of the plasma membrane and its internalization in a membrane-bounded vesicle
Immunoprecipitation
Use of a specific antibody to draw its corresponding protein antigen out of a solution
Single-nucleotide polymorphism (SNP)
Variation between individuals at certain nucleotide positions in the genome.
Vacuole
Very large fluid-filled vesicle found in most plant and fungal cells, typically occupying more than a third of the cell volume.
Nonenveloped virus
Virus consisting of a nucleic acid core and protein capsid only
Lamba bacteriophage
Virus that infects E. coli. Widely used as a DNA cloning vector
Enveloped virus
Virus with a capsid surrounded by a lipid membrane, which is derived from the host cell plasma membrane when the virus buds from the cell https://o.quizlet.com/pLwKgs9xcoc.d3dmySKO.g_m.png
Membrane potential
Voltage difference across a membrane due to a slight excess of positive ions on one side and of negative ions on the other (typically -60 mV)
Phospholipid exchange protein
Water-soluble carrier protein that transfers a phospholipid molecule from one membrane to another.
Amino group
Weakly basic functional group derived from ammonia in which one or more H atoms are replaced by another atom.
Determined
When an embryonic cell has committed to a particular specialized path of development which reflects a change in the internal character of the cell preceding cell differentiation
Leucocyte
White blood cell
Neutrophil
White blood cell that is specialized for the uptake of particular material by phagocytosis and which enters tissues that become infected of inflamed
Alga
Wide range of simple unicellular and multicellular photosynthetic eukaryotes
Mole
X grams of a substance, where X is its relative molecular mass. It consists of 6 x 10^23 molecules of substance
Chiasma
X-shaped connection visible between paired homologous chromosomes during synapsis in meiosis. Represents a site of crossing over
Holliday junction
X-shaped structure observed in DNA undergoing recombination, in which the two DNA molecules are held together at the site of crossing-over
Replication fork
Y-shaped region of a replicating DNA molecule at which the two daughter strands are formed and separate.
Hydrocarbon
compound that has only carbon and hydrogen atoms
Focal adhesion
focal contact/adhesion plaque. Type of anchoring cell junction, forming a small region on the surface of a fibroblast or other cell that is anchored to the extracellular matrix. Attachment is mediated by transmembrane proteins which are linked through other proteins to actin filaments in the cytoplasm
Homolog
one of two or more genes that are similar in sequence as a result of derivation from the same ancestral gene. The term covers both orthologs and paralogs
Intracellular signaling protein
protein tha relays a signal as part of an intracellular signaling pathway. It may either activate the next protein in the pathway or generate a small intracellular mediator
Intermembrane space
subcompartment formed between inner and outer mitochondrial membranes or chloroplasts
Endocytic exocytic cycle
the processes of endocytosis and exocytosis that add and remove plasma membrane from the cell respectively, resulting in no overall change in the cells surface area and volume
Hydroxyl
(-OH). Chemical group consisting of a hydrogen atom linked to an oxygen
Synapsis
(1) In genetic recombination, the initial formation of base pairs between complementary DNA strands in different DNA molecules that occurs at sites of crossing-over between chromosomes. (2) In meiosis, the pairing of maternal and paternal copies of a chromosome as they become attached to each other along their length.
Stroma
(1) The connective tissue in which a glandular or other epithelium is embedded. (2) The large interior space of a chloroplast, containing enzymes that incorporate CO2 into sugars.
Free energy
(G). Energy that can be extracted from a system to drive reactions. Takes into account changes in both energy and entropy
Leptotene
1st phase of division I of meiosis, in which the paired duplicated homologous chromosomes condense and become visible in the light microscope
Cytochrome b-c1 complex
2nd of the 3 electron-driven proton pumps in respiratory chain. It accepts electrons from ubiquinone
Cytochrome oxidase complex
3rd of the 3 electron-driven proton pumps in respiratory chain. It accepts electrons from cytochrome c and generates H2O using O2 as an electron acceptor https://o.quizlet.com/ftcfAhVZ6ncMO-X43dzucA_m.png
Pachytene
3rd stage of division I of meiosis, in which synapsis is complete
Avogadro's number
6 x 10 23 Numer of atoms in 1 gram of H.
Glucose
6-carbon sugar that plays a major role n the metabolism of living cells. Stored in polymeric form as glycogen in animal cells and as starch in plant cells
K+ leak channel
A K+ transporting ion channel in the plasma membrane of animal cells that remains open even in a resting cell
Type III secretion system
A bacterial system for delivering toxic proteins into the cells of their host.
Induction
A change in the developmental fate of one tissue caused by an interaction with another tissue
Metaplasia
A change in the pattern of cell differentiation in a tissue
Class switching
A change that many B cells undergo during immune response from making one class of immunoglobulin to making another
Autosome
A chromosome other than a sex chromosome
Homologous chromosome
A chromosome that has same similar genetic sequence, the same genes in the same loci, size and centromere placement. Each copy being derived from a different parent
Primosome
A complex of DNA primase and DNA helicase that is formed on the lagging strand during DNA replication, improving the efficiency of replication.
Phosphatidylinositol 3-kinase (PI 3-kinase)
A kinase involved in intracellular signaling pathways activated by a variety of cell-surface receptors. It phosphorylates inositol phospholipids at the 3 position of the inositol ring.
Stereocilium
A large, rigid microvillus found in "organ pipe" arrays on the apical surface of hair cells in the ear. It contains a bundle of actin filaments, rather than microtubules, and is thus not a true cilium.
Protofilament
A linear chain of protein subunits joined end to end, which associates laterally with other protofilaments to form cytoskeletal components such as microtubules and intermediate filaments.
Kinetochore microtubule
A microtubule in a mitotic or meiotic spindle that remains attached to the kinetochore on a chromosome
Conditional mutation
A mutation that changes a protein or RNA molecule so that its function is altered only under some conditions (e.g. temperature-sensitive mutations)
Redox reaction
A reaction in which one component becomes oxidized and the other reduced; and oxidation-reduction reaction.
Genetic screen
A search through a large collection of mutations for a mutant with a particular phenotype
Template
A single strand of DNA or RNA whose nucleotide sequence acts as a guide for the synthesis of a complementary strand.
Model organism
A species that has been studies intensively over a long period and serves as a "model" of the biology of a particular type of organism
Section
A very thin slice of tissue, suitable for viewing under the microscope.
Expression vectors
A virus or plasmid that carries a DNA sequence into a suitable host cell and directs the protein synthesis encoded by the sequence
Bacteriophage
A virus that infects bacteria. Widely used as cloning vectors
Spectrin
Abundant protein associated with the cytosolic side of the plasma membrane in red blood cells, forming a rigid network that supports the membrane.
Acetyl CoA
Acetyl + CoA through a tioester group. Water-soluble molecule that carries acetyl groups in cells.
Nicotine adenine dinucleotide phosphate NADP+
Activated carrier closely related to NAD+ that is used extensively in biosynthetic, rather than catabolic, pathways. Reduced form is NADPH
Nicotine adenine dinucleotide NAD+
Activated carrier that participates in an oxidation reaction by accepting a hydride ion (H-) from a donor molecule. The NADH formed is an important carrier of electrons for oxidative phosphorylation
Aminoacyl tRNA
Activated tRNA used in protein synthesis that contains an amino acid linked from its carboxyl group to a hydroxyl group on tRNA.
Secondary immune response
Adaptive immune response to an antigen that is made on a second or subsequent encounter with a given antigen. It is more rapid in onset, stronger, and more specific than the primary immune response.
Primary immune response
Adaptive immune response to an antigen that is made on first encounter with that antigen.
O-linked glycosylation
Addition of an oligosaccharide chain to a protein through the OH group of a serine or threonine side chain
Reduction
Addition of electrons to an atom, as occurs during the addition of hydrogen to a molecule or the removal of oxygen from it. Opposite of oxidation.
DNA methylation
Addition of methyl groups to DNA. Extensive addition of these groups in the cytosine base of CG sequences keeps genes in an inactive state in eukaryotes. In prokaryotes, cytosines and adenines can be marked this way to protect their native DNA (primitive immune system against bacteriophages)
DNA supercoiling
Additional twisting of the DNA helix that occurs in response to the superhelical tension created when, for example, a circular DNA is partly unwound
Adaptation
Adjustment of sensitivity followed by repeated stimulation
Allele
Alternative forms of a gene that occupy the same position on homologous chromosomes
Sorting signal
Amino acid sequence that directs the delivery of a protein to a specific location outside the cytosol.
Oncogene
An altered gene whose product can act in a dominant fashion to help make a cell cancerous. Typically a mutant form of a normal gene (porto-oncogene) involves in the control of cell growth or division
Immunoglobulin
An antibody molecule. Higher vertebrates have five classes of immunoglobulin (A, D, E, G and M) each with different role in the immune response
Ion
An atom that has either gained or lost electrons to acquire a charge
Mitogen
An extracellular substance, such as a growth factor, that stimulates cell proliferation
Prion
An infectious abnormal form of a normal protein that is replicated in the host by forcing the normal proteins of the same type to adopt the aberrant structure.
Phosphatidylinositol
An inositol phospholipid.
Mosaic
An organism made of a mixture of cells with different genotypes
Pathogen
An organism or other agent that causes disease.
Meristem
An organized group of dividing cells whose derivatives give rise to the tissue and organs of a flowing plant. Key examples are apical meristems at the tips of shoots and roots
Fermentation
Anaerobic energy-yielding metabolic pathway that produces acids, gases or alcohol from sugars in the absence of oxygen
Autoantibody
Antibody produced by an organism against an antigen of its own cells and tissues
Monoclonal antibody
Antibody secreted by a hybridoma clone. Each such clone is derived from a single B cell, all of the antibody molecules produced are identical
Recombinant DNA
Any DNA molecule formed by joining DNA segments from different sources. Recombinant DNAs are widely used in the cloning of genes, in the genetic modification of organisms, and in molecular biology generally.
Carcinogen
Any agent that causes cancer (e.g. chemical or radiation)
Somatic cell
Any cell of a plant or animal other than a germ cell or germ cell precursor.
Post-transcriptional control
Any control on gene expression that is exerted at a stage after transcription has begun.
Ganglioside
Any glycolipid having one or more sialic acid residues in its structure. Found in the plasma membrane of eukaryotic cells and especially abundant in nerve cells https://o.quizlet.com/BlZqTbGlp9TZBGjMFBjRwA_m.jpg
Ligand
Any molecule that binds to a specific site on a protein or other molecule (latin ligare)
Solute
Any molecule that is dissolved in a liquid. This liquid is called a solvent.
Rab protein
Any of a large family of monomeric GTPases present in the plasma membrane and organelle membranes that are involved in conferring specificity on vesicle docking.
Nucleoporin
Any of a number of different proteins that make up nuclear pore complexes
Respiratory enzyme complex
Any of the major protein complexes of the mitochondrial respiratory chain that act as electron-driven proton pumps to generate the proton gradient across the inner membrane.
Astral microtubule
Any of the microtubules in a mitotic spindle emanating from the aster that are not attached to a chromosome's kinetochore https://o.quizlet.com/dywcGZp4ImDUZ8Wb.BuIIg_m.jpg
Hypervariable region
Any of three small regions within the variable region of an immunoglobulin light chain or heavy chain that show the highest variability from molecule to molecule. These regions determine the specificity of the antigen-binding site
Ubiquitin ligase
Any one of a large number of enzymes that attach ubiquitin to a protein, thus marking it for destruction in a proteasome. The process catalyzed by a ubiquitin ligase is called ubiquitylation.
Ribosomal RNA
Any one of a number of specific RNA molecules that form part of the structure of a ribosome and participate in the synthesis of proteins. Often distinguished by their sedimentation coefficient, such as 28S rRNA or 5S rRNA.
Gene regulatory protein
Any protein that binds to a specific DNA sequence to alter gene expression
General transcription factor
Any protein whose assembly around the TATA box is required for the initiation of transcription of most eukaryotic genes
Globular protein
Any protein with an approximately rounded shape. Such proteins are contrasted with highly elongated, fibrous proteins such as collagen
Glycoprotein
Any protein with one or more oligosaccharide chains covalently linked to amino acid side chains. Most secreted or exposed (on the outer surface of plasma membrane) proteins
Connective tissue
Any supporting tissue that lies between other tissues and consists of cells embedded in an extracellular matrix (e.g. bone, cartilage)
Myeloid cell
Any white blood cell other than lymphocytes
Reverse genetics
Approach to discovering gene function that starts from the DNA (gene) and protein and then creates mutants to analyze the gene's function.
Benzene
Aromatic molecule composed of a six-membered carbon ring. Contains three alternative double bonds. https://o.quizlet.com/mZ1QIdB-TRVzIcs3dvpGYg_m.png
Mitotic spindle
Array of microtubules and associated molecules that forms between the opposite poles of a eukaryotic cell during mitosis and serves to move the duplicated chromosomes apart
Liposome
Artificial phospholipid bilayer vesicle formed from an aqueous suspension of phospholipid molecules https://o.quizlet.com/w0JCUjLutMS-JjgseF4oPA_m.jpg
Black membrane
Artificial planar lipid bilayer membrane
Complex
Assembly of molecules that are held together by non covalent bonds
Electron acceptor
Atom or molecule that takes up electrons readily, thereby gaining an electron and becoming reduced (e.g. oxygen, nitrate, iron)
Consensus sequence
Average of most typical form of a sequence that is reproduced with minor variations in a group of related DNA, RNA or protein sequences. It shows the nucleotide or amino acid most commonly found at each position. The preservation of it implies that it is functionally important
Anteroposterior
Axis running from head to tail https://o.quizlet.com/Bos6Imd5Nvaqox4bZyLmRQ_m.png
Dorsal
Back of an animal. Upper surface of a leaf or wing
Budding yeast
Baker's yeast or Saccharomyces cerevisiae
Gray crescent
Band of pale pigmentation that appears in the egg of some species of amphibians, opposite the site of sperm entry following fertilization. Caused by rotation of the egg cortex and associated pigment granules. Marks the future dorsal side https://o.quizlet.com/i/eVlvZLj8PQE4i4yQLDYZbg_m.jpg
Nucleosome
Beadlike structure in eukaryotic chromatin composed of a short length (146 bp) of DNA wrapped around a core of histone proteins, fundamental structural unit of chromatin
Adhesion belt - Zonula adherens
Beltlike adherens junction belt that encircles the apical end of an epithelial cell and attaches it to the adjoining cell. https://o.quizlet.com/i/e9iDNTeT8DdHITy4rzyHGg_m.jpg
Nitrogen fixation
Biochemical process carried out by certain bacteria that reduces atmospheric nitrogen to ammonia, leading eventually to various nitrogen containing metabolites
Chromatography
Biochemical technique in which a mixture of substances is separated by charge, size, or some other property allowing it to partition in moving phase and stationary phase
Blotting
Biochemical technique in which macromolecules are separated on an agarose/polyacrylamide gel and transferred to a nylon membrane/sheet of paper for their immobilization https://o.quizlet.com/79X2Sf-i8VEDrET6AJNWWw_m.png
Axoneme
Bundle of microtubules and associated proteins that forms the core of a cilium or flagellum in an eukaryotic cell and is responsible for their movement https://o.quizlet.com/zE-xO9qOCWu7VpkYDks2kw_m.png
Acetyl
CH3-C=O Functional group derived from acetic acid. Added to some proteins as post translational modification.
Calcium pump
Ca2+ ATPase. Transport protein in the sarcoplasmic reticulum membrane that pumps Ca2+ out of the cytoplasm into the sarcoplasmic reticulum using ATP https://o.quizlet.com/W9zBV7bHlzUnlhlpH7ab1g_m.jpg
Protein kinase C (PKC)
Ca2+-dependent protein kinase that, when activated by diacylglycerol and an increase in the concentration of Ca2+, phosphorylates target proteins on specific serine and threonine residues.
Sarcoma
Cancer of connective tissue.
Carcinoma
Cancer of epithelial cells. Most common form of human cancer
Leukemia
Cancer of white blood cells
Disaccharide
Carbohydrate molecule consisting of two covalently joined monosaccharide units
Carboxyl group
Carbon atom linked to a oxygen atom by a double bond and to hydroxyl group. Weak acids https://o.quizlet.com/i/RcoBzTimI5rAKpGhNIzHZQ_m.jpg
Carbonyl group
Carbon atom linked to a oxygen atom by a double bond https://o.quizlet.com/iAVSuovpDb-iQy..vjL9BA_m.jpg
Colorectal tumor
Carcinoma of the epithelium linen of the colon and rectum
Uniporter
Carrier protein that transports a single solute from one side of the membrane to the other.
Antiporter
Carrier protein that transports two different ions or small molecules across a membrane in opposite direction, simultaneously or in sequence https://o.quizlet.com/sAmsLikWYszq-tlP13wWig_m.png
Symporter
Carrier protein that transports two types of solute across the membrane in the same direction.
Chondrocyte
Cartilage cell. Connective tissue cell that secretes the matrix of cartilage
Granulocyte
Category of white blood cell distinguished by conspicuous cytoplasmic granules https://o.quizlet.com/fVGEs1IE51nq0Hz2DELsJA_m.png
Lumen
Cavity enclosed by an epithelial sheet or by a membrane
Neural cell adhesion molecule N-CAM
Cell adhesion molecule of the immunoglobulin superfamily, expressed by many cell types including most nerve cells. Mediates Ca2+ independent cell-cell attachement in vertebrates
Glycocalyx
Cell coat. Carbohydrate-rich layer that forms the outer coat of an eukaryotic cell. Composed of oligosaccharides linked to intrinsic plasma membrane glycoproteins and glycolipids, as well as glycoproteins and proteoglycans that have been secreted and reabsorbed onto the cell surface https://o.quizlet.com/i/gX78Sst4XZjr_zHuVEfEMQ_m.jpg
Nurse cell
Cell connected by cytoplasmic bridges to a developing oocyte and which thereby supplies it with ribosomes, mRNAs, and proteins needed for the development of the early embryo
Dendritic cell
Cell derived from bone marrow and present in lymphoid and other tissues that is specialized for the uptake of particulate material by phagocytosis and which acts as a professional antigen-presenting cell in immune responses
Embryonic stem cell (ES cell)
Cell derived from the inner cell mass of the early mammalian embryo that can give rise to all the cells in the body. It can be grown in culture, genetically modified and inserted into a blastocyst to develop a transgenic animal
Asymmetric cell division
Cell division that produces two daughter cells that differ in size or in absence or presence of cytoplasmic constituent
Platelet
Cell fragment, lacking a nucleus, that breaks off from a megakaryocyte in the bone marrow and is found in large numbers in the bloodstream. It helps initiate blood clotting when blood vessels are injured.
Adherens junction
Cell junction in which the cytoplasmic face of the plasma membrane is attached to actin filaments https://o.quizlet.com/i/_0_IrBN31y_OWDfZwCwx5Q_m.jpg
Hybridoma
Cell line used in the production of monoclonal antibodies
Photoreceptor
Cell or molecule that is sensitive to light.
Primordial germ cell
Cell set aside early in embryonic development that is a precursor to germ cells that give rise to gametes.
Autocrine signaling
Cell signaling in which a cell recreates signal molecules that act on itself or adjacent cells of the same type
Effector cell
Cell that carried out the final response or function of a particular process. (e.g. lymphocytes and phagocytes destroy pathogens and remove them from the body)
Antigen-presenting cell
Cell that displays foreign antigens complexed with MHC (major histocompatibility complex) molecules on its surface
Melanocyte
Cell that produces the dark pigment melanin. Responsible for pigmentation of skin and hair
Osteoblast
Cell that secretes matrix of bone
Chromaffin cell
Cell that stores adrenaline in secretory vesicles and secretes it in times of stress when stimulated by the nervous system
Neuron
Cell with long processes specialized to receive, conduct and transmit signals in the nervous system
Heterocaryon
Cell with two or more genetically different nuclei; produced by the fusion of two or more different cells
Anaerobic
Cell, organism or process that functions in the absence of O2
Contact-dependent signaling
Cell-cell communication in which the signal molecule remains bounds https://o.quizlet.com/zbLNfOaVs6pW2a8Jhm240g_m.jpg
Tight junction
Cell-cell junction that seals adjacent epithelial cells together, preventing the passage of most dissolved molecules from one side of the epithelial sheet to the other.
CD28
Cell-surface protein on T cells that binds the B7 protein on antigen-presenting cells providing an additional signal required for the activation of a naive T cell by an antigen
G-protein linked receptor
Cell-surface receptor that associates with an intracellular trimeric GTP-binding protein after receptor activation by an extracellular ligand. Seven-pass transmembrane proteins
Convergent extension
Cellular rearrangement within a tissue that causes it to extend in one dimension and shrink in another https://o.quizlet.com/lld1wc2IlfwEKgF0w7ykFQ_m.png
Unfolded protein response
Cellular response triggered by an accumulation of misfolded proteins in the endoplasmic reticulum. It involves increased transcription of ER chaperones and degradative enzymes.
Matrix space
Central subcompartment of a mitochondrion, bounded by the inner mitochondrial membrane. The corresponding compartment in a chloroplast, which is more commonly known as stroma
Centrosome
Centrally located organelle of animal cells that is the microtubule organizing center and acts as the spindle pole during mitosis. Consists of a pair of centrioles
Complex oligosaccharide
Chain of sugars attached to a glycoprotein
High-mannose oligosaccharide
Chain of sugars attached to a glycoprotein which contains many mannose residues
N-linked oligosaccharide
Chain of sugars attached to a protein through the NH2 group of the side chain of an asparagine residue
Dysplasia
Change in cell growth and behavior in a tissue in which the structure becomes disordered
Denaturation
Change in conformation of a protein or nucleic acid caused by heat or exposure to chemicals that results in loss of biological function
Free energy change
Change in the free energy during a reaction:
Point mutation
Change of a single nucleotide in DNA, especially in a region of DNA coding for protein.
Immunoglobulin domain
Characteristic protein domain of about 100 amino acids found in immunoglobulin light and heavy chains. Similar domains, immunoglobulin-like domains are present in many other proteins involved in cell-cell interactions and antigen recognition and define the Ig superfamily
Peptide map
Characteristic two-dimensional pattern (on paper or gel) formed by the separation of the mixture of peptides produced by the partial digestion of a protein.
Spindle-attachment checkpoint
Checkpoint that operates during mitosis to ensure that all chromosomes are properly attached to the spindle before sister-chromatid separation starts.
Peptide bond
Chemical bond between the carbonyl group of one amino acid and the amino group of a second amino acid-a special form of amide linkage. Peptide bonds link amino acids together in proteins.
Noncovalent attraction
Chemical bond in which no electrons are shared. They are relatively weak, but can sum together to produce strong, highly specific interactions between molecules. Some examples are hydrogen bonding, Van der Waals forces, etc
Label
Chemical group (radioactive atom or fluorescent dye) added to a molecule in order to follow its progress in a biochemical reaction or to locate it spatially
Sulfhydryl (thiol, -SH)
Chemical group containing sulfur and hydrogen found in the amino acid cysteine and other molecules. Two sulfhydryls can join to produce a disulfide bond.
Neurotransmitter
Chemical messengers, small signal molecule that transmit a signal across a chemical synapse from one neuron to another target neuron, e.g. acetylcholine, glutamate, GABA, glycine
Condensation reaction
Chemical reaction in which two molecules are covalently linked through -OH groups with the removal of H2O
Fixative
Chemical reagent such as formaldehyde or osmium tetroxide used to preserve cells for microscopy. Samples created with these samples are said to be "fixed" and the process is called "fixation"
Genomic DNA
Chromosomal DNA constituting the genome of a cell or an organism inherited from generation to generation
Sex chromosome
Chromosome that may be present or absent, or present in a variable number of copies, according to the sex of the individual. In mammals, the X and Y chromosomes.
Preprophase band
Circumferential band of microtubules and actin filaments that forms around a plant cell under the plasma membrane prior to mitosis and cell division.
Gq
Class of receptor-coupled G protein that activates phospholipase C-beta and originates the inositol phospholipid signaling https://o.quizlet.com/nVTkQXGEOkV5WcUUQhAlgA_m.png
Hydrolysis
Cleavage of a covalent bond with accompanying addition of water, -H added to one product of the cleavage and -OH to the other https://o.quizlet.com/TxAIQ6l7jyvYIZI8DoOuzg_m.png
Bacterial artificial chromosome (BAC)
Cloning vector that can accommodate large pieces of DNA (1 million bp)
Ganglion
Cluster of nerve cells and associated glial cells located outside the central nervous system
CD8
Co-receptor protein found on cytotoxic T cells that binds to class I MHC molecules outside the antigen-binding site https://o.quizlet.com/AcgtttzSY1EkEUXfQ8binQ_m.jpg
CD4
Co-receptor protein found on helper T-cells that binds to class II MHC molecules outside the antigen-binding site
Epithelium
Coherent cell sheet formed from one or more layers of cells covering an external surface or lining a cavity
Ionic bond
Cohesion between two atoms, one with a positive charge and other with a negative charge. One type of non covalent bond
DNA library
Collection of cloned DNA molecules, representing the entire genome (genomic library) or the DNA copies of the messenger RNA produced by a cell (cDNA library)
Cytochrome
Colored, heme (Fe2+)-containing protein that transfers electrons during cellular respiration and photosynthesis
Lymph
Colorless fluid derived from blood by filtration through capillary walls. Carries lymphocytes in a special system of ducts and vessels
Chelate
Combine with a metal ion (Fe2+, Ca2+, Mg2+), reversibly and with high affinity
Fibroblast
Common cell type found in connective tissue. Secretes an extracellular matrix rich in collagen. Migrates and proliferates readily in wounded tissue and in tissue culture
pH
Common measure of the acidity of a solution: "p" refers to power of 10, "H" to hydrogen. Defined as the negative logarithm of the hydrogen ion concentration in moles per liter (M). Thus on the pH scale, pH 3 is acidic and pH 9 is alkaline.
Yeast
Common term for several families of unicellular fungi. Includes species used for brewing beer and making bread, as well as pathogenic species (that is, species that cause disease).
Leucine-rich repeat protein
Common type of receptor serine/threonine kinase in plants. Characterized by a tandem array of leucine-rich repeat sequences in the extracellular portion
Plasmodesmata
Communicating cell-cell junction in plants in which a channel of cytoplasm lined by plasma membrane connects two adjacent cells through a small pore in their cell walls.
Synapse
Communicating cell-cell junction that allows signals to pass from a nerve cell to another cell. In a chemical synapse the signal is carried by a diffusible neurotransmitter; in an electrical synapse a direct connection is made between the cytoplasms of the two cells via gap junctions.
Gap junction
Communication cell-cell junction that allows ions and small molecules to pass from the cytoplasm of one cell to the cytoplasm of the next. Each is composed of two connexions. Analogous to plasmodesmata in plants https://o.quizlet.com/7qzvc8KFPNgDgYoTeJl1Eg_m.jpg
cDNA
Complementary DNA. Molecule made as a copy of messenger RNA by reverse transcriptase and therefore lacking genomic introns.
M-phase Ck
Complex formed by an M-cyclin and the corresponding cyclin-dependent kinase
G1 Cdk
Complex formed in vertebrate cells by a G1 cyclin and the corresponding Cdk
G1/S Cdk
Complex formed in vertebrate cells by a G1/S cyclin and the corresponding Cdk
S-Cdk
Complex formed in vertebrate cells by and S-cyclin and the corresponding cyclin-dependent kinase (Cdk)
Extracellular matrix
Complex network made up of polysaccharides (cellulose or glycosaminoglycans) and proteins (collagen) secreted by cells. Serves as structural element in tissues and also influences their development and behavior
Chromatin
Complex of DNA, histones and nonhistone proteins in the nucleus of eukaryotic cells
Major histocompatibility complex
Complex of highly polymorphic genes in vertebrates. They code for a large gamily of cell-surface glycoproteins that bind to peptide fragments of foreign proteins and present them to T cells to induce an immune response
Condensin
Complex of proteins involved in chromosome condensation prior to mitosis
Kinetochore
Complex structure formed from proteins on a mitotic chromosome to which microtubules attach and which plays an active part in chromosomal movement to the poles. It forms on the centromere
Tertiary structure
Complex three-dimensional form of a folded polymer chain, especially a protein of RNA molecule.
Subunit
Component of a multicomponent complex-for example, one protein component of a protein complex or one polypeptide chain of a multichain protein.
Fatty acid
Compound that contains a carboxylic acid attached to a long hydrocarbon chain that can be used as energy source during metabolism and as a starting point for lipid synthesis https://o.quizlet.com/i/fdRPp7kvIP6mp96jm_W7Dg_m.jpg
Image processing
Computer treatment of images gained from microscopy that reveal information not immediately visible to the eye
Critical concentration
Concentration of a protein monomer that is in equilibrium with the assembled form of the protein (actin into actin filaments or tubulin into microtubules)
Chromosome
Condensed structure of a very long DNA molecule and associated proteins that carries the hereditary information of an organism. Evident in mitosis or meiosis
Fat cell
Connective-tissue cell that produces and stores fat in animals. Adipocyte
TATA box
Consensus sequence in the promoter region of many eukaryotic genes that binds a general transcription factor and hence specifies the position at which transcription is initiated.
Default pathway
Constitutive secretory pathway that automatically delivers material from the Golgi apparatus to the plasma membrane if no other sorting signals are present
Centromere
Constricted region of a mitotic chromosome that holds sister chromatids together. Site where the kinetochore forms that captures microtubules from the mitotic spindle
Diploid
Containing two sets of homologous chromosomes and therefore two copies of genetic loci
Cytoplasm
Contents of a cell contained within its plasma membrane but in eukaryotes, outside of the nucleus
Cytosol
Contents of the main compartment of the cytoplasm, excluding membrane-bounded organelles. https://o.quizlet.com/-0-dZadB1En9orz0Ds9BMA_m.jpg
RNA processing control
Control of gene expression by controlling how the RNA transcript is spliced or otherwise processed.
Transcriptional control
Control of gene expression by controlling when and how often the gene is transcribed.
Translational control
Control of gene expression by selection of which mRNAs in the cytoplasm are translated by ribosomes.
Transcription (DNA transcription)
Copying of one strand of DNA into a complementary RNA sequence by the enzyme RNA polymerase.
Prenylation
Covalent attachment of an isoprenoid lipid group to a protein.
High-energy bond
Covalent bond whose hydrolysis releases an unusually large amount of free energy. A group linked to a molecule by such bod is readily transferred from one molecule to another (phosphodiester bonds in ATP and thirster linkage in acetyl CoA)
Disulfide bond
Covalent linkage formed between two sulfhydryl groups on cysteine. For extracellular proteins, a common way of joining two proteins together or linking different parts of the same protein, formed in the ER
Nucleation
Critical stage in the assembly of a polymeric structure (e.g. microtubule) at which a small cluster of monomers aggregates in the correct arrangement to initiate rapid polymerization. Rate-limiting step in an assembly process
Heme
Cyclic organic molecule containing an iron atom that carries oxygen in hemoglobin and carries an electron in cytochromes
Interferon-gamma
Cytokine secreted by certain types of T cells after activation, and which enhances the anti-viral response and macrophage activation
Plastid
Cytoplasmic organelle in plants, bounded by a double membrane, that carries its own DNA and is often pigmented. Chloroplasts are plastids.
Focal adhesion kinase
Cytoplasmic tyrosine kinases present at cell-matrix junctions in association with cytoplasmic tails of integrins
Dynamin
Cytosolic GTPase that binds to the neck of a clathrin-coated vesicle in the process of budding from the membrane and which is involved in completing vesicle formation https://o.quizlet.com/goPzCh9Rbhtms4Pfc05zcg_m.png
Natural killer cell
Cytotoxic cell of the innate immune system that can kill virus-infected cells
CG island
DNA region with a high density of CG sequences. Usually remain unmethylated
Mismatch repair
DNA repair process that corrects mismatched nucleotides inserted during DNA replication. A short stretch of newly synthesized DNA including the mismatched nucleotide is removed and replaced with the correct sequence with reference to the template strand
Insulator element
DNA sequence that blocks the interaction between promoters and enhancers
Regulatory sequence
DNA sequence to which a gene regulatory protein binds to control the rate of assembly of the transcriptional complex at the promoter.
Gene control region
DNA sequences required to initiate transcription of a given gene and control the rate of initiation
Homeodomain
DNA-binding domain that defines a class of gene regulatory proteins important in animal development
Helix-loop-helix
DNA-binding structural motif present in many gene regulatory proteins
Zinc finger
DNA-binding structural motif present in many gene regulatory proteins. Composed of a loop of polypeptide chain held in a hairpin bend bound to a zinc atom.
Probe
Defined fragment of RNA or DNA, radioactively or chemically labeled, used to locate specific nucleic acid sequences by hybridization.
Proteolysis
Degradation of a protein by hydrolysis at one or more of its peptide bonds.
Brush border
Dense covering of microvilli on the apical surface of epithelial cells in intestine/kidney that aid absorption by increasing the cell's surface area
Anchorage dependence
Dependence of cell growth on attachment to a subtratum
Polyploid
Describes a cell or an organism that contains more than two sets of homologous chromosomes.
Polymorphic
Describes a gene with many different alleles, none of which is predominant in the population.
Saturated
Describes a molecule containing carbon-carbon bonds that has only single covalent bonds.
Unsaturated
Describes a molecule that contains one or more double or triple carbon-carbon bonds, such as isoprene or benzene.
Hydrophobic
Describes a non polar molecule or part of a molecule that cannot form energetically favorable interactions with water and therefore it is insoluble in water (water hating, lipophilic)
Hydrophilic
Describes a polar molecule or part of a molecule that forms enough energetically favorable interactions with water molecules to dissolver readily in water (water loving <3)
Molar
Describes a solution with a concentration of 1 mole of a substance dissolved in 1 liter of solution
Hypertonic
Describes any medium with a sufficiently high concentration of solutes to cause water to move out of a cell due to osmosis
Hypotonic
Describes any medium with a sufficiently low concentration of solutes that causes water to move into a cell due to osmosis
Post-translational
Describes any process involving a protein that occurs after protein synthesis is completed.
Co-translational
Describes import of a protein into the endoplasmic reticulum before the polypeptide chains completely synthesized
Homologous
Describes organs or molecules that are similar because of their common evolutionary origin. Specifically describes similarities in protein or nucleic acids sequence
Dorsoventral
Describes the axis running from the back to the belly of an animal or from the upper side to the underside of a structure
Osmolarity
Describes the concentration of a solution terms of the osmotic pressure it can exert
Malignant
Describes tumors and tumor cells that are invasive and/or able to undergo metasis
Cell fate
Describes what a particular cell at a given stage of development will normally give rise to
DNA sequencing
Determination of the order of nucleotides in a DNA molecule
Embryogenesis
Development of an embryo from a fertilized egg or zygote
Spermatogenesis
Development of sperm.
Restriction map
Diagrammatic representation of a DNA molecule indicating the sites of cleavage by various restriction enzymes.
Position effect
Differences in gene expression that depend on the position of the gene on the chromosome and probably reflect differences in the state of the chromatin along the chromosome.
Autophagy
Digestion of worn-out organelles by the cell's own lysosomes
Heterozygote
Diploid cell or individual having two different alleles of one or more specified genes
Homozygote
Diploid cell or organism having two identical alleles of a specific gene or set of genes
Zygote
Diploid cell produced by fusion of a male and female gamete. A fertilized egg.
Chemotaxis
Directed movement of a cell or organism towards or away form a diffusible chemical
Axonal transport
Directed transport of organelles and molecules along a nerve cell axon https://o.quizlet.com/i/PFT0PnAOySF-PUhNqrBhCg_m.jpg
Sucrose
Disaccharide composed of one glucose unit and one fructose unit. The major form in which glucose is transported between plant cells.
Division II of meiosis
Division in which the chromatids of each duplicated chromosome are segregated to opposite poles of the dividing cell
Division I (meiosis)
Division in which the members of each pair of duplicated homologous chromosomes are segregated to opposite poles of the dividing cell
Cytokinesis
Division of the cytoplasm of a plant/animal cell into 2, different from the divisions of its nucleus (mitosis)
Mitosis
Division of the nucleus of a eukaryotic cell, involving condensation of the DNA into visible chromosomes, and separation of the duplicated chromosomes to form two identical sets
Nuclear envelope
Double membrane surrounding the nucleus. Consists of an outer and inner membrane and is perforated by nuclear pores https://o.quizlet.com/i/LhyVPUJ18y3CYXQVmAFyjQ_m.jpg
Proton-motive force
Driving force that moves protons across a membrane as a result of an electrochemical proton gradient.
Bivalent
Duplicated chromosome paired with its homologous duplicated chromosome at the beginning of meiosis. 4 chromatids. 2 sister chromatids of two homologous chromosomes https://o.quizlet.com/X8rEA8r84OHUkbhBdwbR2g_m.png
Centrosome cycle
Duplication of the centrosome during interphase and its separation during mitosis to form poles of mitotic spindle
Fluorescein
Dye that fluoresces green when illuminated with blue or UV light
Blastula
Early stage of an animal embryo, constituting of a hollow ball of cells before gastrulation begins https://o.quizlet.com/GvZK4HXqaw6tPneUBmS-IQ_m.png
Action potential - Nerve impulse
Electrical excitation in the plasma membrane of cells. Makes long distance nervous system signaling possible.
Immunogold electron microscopy
Electron microscopy technique in which cellular structures or molecules of interest are labeled with antibodies tagged with electron-dense gold particles.
Cryoelectron microscopy
Electron microscopy technique in which the objects to be viewed are rapidly frozen
Iron-sulfur center
Electron transporting group consisting of either two or four iron atoms bound to an equal number of sulfur atoms, found in a class of electron-transport proteins https://o.quizlet.com/ap7Q77OmEvFiBItIhFa1jw_m.png
Respiratory chain
Electron-transport chain in the inner mitochondrial membrane that receives high-energy electrons derived from the citric acid cycle and generates the proton gradient across the membrane that is used to power ATP synthesis.
Patch-clamp recording
Electrophysiological technique in which a tiny electrode tip is sealed onto a patch of cell membrane, making it possible to record the flow of current though individual ion channels in the patch https://o.quizlet.com/MYU87T-zczSLiNpArCmB5Q_m.png
Motif
Element of structure or pattern that recurs in many contexts. A small structural domain that can be recognized in a variety of proteins
Photon
Elementary particle of light and other electromagnetic radiation.
Ectoderm
Embryonic tissue that is the precursor of the epidermis and nervous system
Endoderm
Embryonic tissue that is the precursor of the gut and associated organs
Telomere
End of a chromosome, associated with a characteristic DNA sequence that is replicated in a special way. Counteracts the tendency of the chromosome otherwise to shorten with each round of replication.
Amino terminus
End of a polypeptide chain carrying a free alpha amino group
Carboxyl terminus
End of a polypeptide chain that carries a free carbonyl group https://o.quizlet.com/bv2Al5BJyln-AczYoQD98Q_m.jpg
Rough endoplasmic reticulum (rough ER)
Endoplasmic reticulum with ribosomes on its cytosolic surface. Involved in the synthesis of secreted and membrane-bound proteins.
Fat
Energy-storage lipid in cells composed of triglycerides-fatty acids esterified with glycerol
GTPase
Enzyme activity that converts GTP to GDP. Also common name for monomeric GTP-binding proteins
Phospholipase C-beta (PLC-B)
Enzyme bound to the cytoplasmic face of the plasma membrane that converts membrane phosphatidylinositol 4,5-bisphosphate to diacylglycerol (which remains in the plasma membrane) and inositol 1,4,5-triphosphate (IP3). It is activated by certain G proteins to trigger the inositol phospholipid signaling pathway.
ATP synthase
Enzyme complex in the inner membrane of mitochondria and chloroplast thylakoid membrane that catalyzes the formation of ATP from ADP and inorganic phosphate during oxidative phosphorylation and photosynthesis, respectively https://o.quizlet.com/6QTWr4l4k4I7OkuvJVp5ng_m.png
Reverse transcriptase
Enzyme first discovered in retroviruses that makes a double-stranded DNA copy from a single-stranded RNA template molecule.
Protease
Enzyme such as trypsin that degrades proteins by hydrolyzing some of their peptide bonds.
Aminoacyl-tRNA synthetase
Enzyme that attaches the correct amino acid to a tRNA
DNA topoisomerase
Enzyme that binds to DNA and reversibly breaks a phosphodiester bond in one or both strands allowing the DNA to rotate at that point. It prevents DNA tangling during replication
Lipase
Enzyme that catalyzes the cleavage of fatty acids from the glycerol moiety of a triglyceride
Lysozyme
Enzyme that catalyzes the cutting of polysaccharide chains in the cell walls of bacteria
ATPase
Enzyme that catalyzes the hydrolysis of ATP
RNA polymerase
Enzyme that catalyzes the synthesis of an RNA molecule on a DNA template from nucleoside triphosphate precursors.
Ribonuclease
Enzyme that cuts an RNA molecule by hydrolyzing one or more of its phosphodiester bonds.
Telomerase
Enzyme that elongates telomere sequences in DNA.
DNA helicase
Enzyme that is involved in opening the DNA helix into its single strands for DNA replication
DNA ligase
Enzyme that joins the ends of two strands of DNA together with a covalent bond to make a continuous DNA strand
Ligase
Enzyme that joins together two molecules in an energy-dependent process. e.g. joining together DNA nucleotides end to end through phosphodiester bonds
Topoisomerase (DNA topoisomerase)
Enzyme that makes reversible cuts in a double-helical DNA molecule for the purpose of removing knots or unwinding excessive twists.
Phosphoprotein phosphatase
Enzyme that removes a phosphate group from a protein by hydrolysis.
Signal peptidase
Enzyme that removes a terminal signal sequence from a protein once the sorting process is complete.
Phosphatase
Enzyme that removes phosphate groups from a molecule.
DNA polymerase
Enzyme that synthesizes DNA by forming phosphodiester bonds between nucleotides using a DNA template as a guide
DNA primase
Enzyme that synthesizes a short RNA sequence complementary to a DNA template in order to function as a primer and initiate DNA replication
Protein kinase
Enzyme that transfers the terminal phosphate group of ATP to a specific amino acid of a target protein.
Catabolism
Enzyme-catalyzed reactions in a cell by which complex molecules are degraded to simpler ones with release of energy. Intermediates are called catabolites
Epidermis
Epithelial layer covering the outer surface of the body. It has different structures in different animal groups and it also names the outer layer of plant tissue
Coiled-coil
Especially stable rodlike structure in proteins formed by two alpha helices coiled around each other
Internal membrane
Eukaryotic cell membrane other than pasma membrane (ER of Golgi membranes)
Phylogeny
Evolutionary history of an organism or group of organisms, often presented in chart form as a phylogenetic tree.
Chromosomal crossing over
Exchange of DNA between paired homologous chromosomes in meiosis, in which genetic recombination and crossovers are visible
Clonal selection theory
Explains how adaptive immune system can respond to millions of different antigens in a highly specific way
Dendrite
Extension of a nerve cell, typically branched and relatively short, that receives stimuli from other nerve cells
Activation Energy
Extra energy possessed by atoms/molecules apart from its ground-state energy that is used to undergo chemical reactions
Fibronectin
Extracellular matrix glycoprotein that binds to membrane receptors integrins. This protein is involved in adhesion of cells to the matrix and the guidance of migrating cells during embryogenesis https://o.quizlet.com/iP3yZdzrTgZtVZdCB6dKxw_m.png
Laminin
Extracellular matrix protein found in basal laminae, where it forms a sheetlike network
Signal molecule
Extracellular or intracellular molecule that cues the response of a cell to the behavior of other cells or objects in the environment.
Growth factor
Extracellular polipeptide signal molecule that can stimulate a cell to grow or proliferate.
Cytokine
Extracellular signal protein or peptide that acts as a local mediator in cell-cell communication
Survival factor
Extracellular signal required for a cell to survive; in its absence the cell will undergo apoptosis and die.
Collagen fibril
Extracellular structure formed by self assembly of secreted collagen subunits. Abundant constituent of the extracellular matrix
Collagen
FIBROUS protein rich in GLYCINE and PROLINE that is a major component of the extracellular matrix and connective tissues. Type I, skin, tendon, bone. Type II, cartilage. Type IV, basal laminae
trans face
Face of a Golgi stack at which material leaves the organelle for the cell surface or another cell compartment. It is adjacent to the trans Golgi network.
cis face
Face of a Golgi stack where material enters the organelle. Adjacent to the cis Golgi network https://o.quizlet.com/cL5JPd0zJbcql3QpihgLbg_m.png
Src family
Family of cytoplasmic tyrosine kinases that associate with the cytoplasmic domains of some enzyme-linked receptors (for example, the T cell antigen receptor) that lack intrinsic tyrosine kinase activity. They transmit a signal onwards by phosphorylating the receptor itself and other signaling proteins.
Fc receptor
Family of receptors specific for the Fc region (constant region "bottom of the Y") of various classes of antibodies
Adipocyte
Fat cell
Connective tissue cell
Fibroblasts, cartilage cells (chondrocytes), bone cells (osteoblasts, osteocytes), fat cells (adipocytes), smooth muscle cells. Any of the various cell types found in connective tissue.
Nuclear lamina
Fibrous meshwork of proteins on the inner surface of the inner nuclear membrane. It is made up of a network of intermediate filaments formed from nuclear lamins https://o.quizlet.com/i/_8PLXchRgmDt88H5GTQADA_m.jpg
Intermediate filament
Fibrous protein filament (10 nm in diameter) that forms roselike networks in animal cells. One of the three most prominent types of cytoskeleton filaments
Telophase
Final stage of mitosis in which the two sets of separated chromosomes decondense and become enclosed by nuclear envelopes.
NADH dehydrogenase complex
First of the three electron-driven proton pumps in the mitochondrial respiratory chain. It accepts electrons from NADH
Prophase
First stage of mitosis, during which the chromosomes are condensed but not yet attached to a mitotic spindle.
Endothelial cell
Flattened cell type that forms a sheet called endothelium that line all blood vessels
Cisterna
Flattened membrane-bounded compartment found in the Golgi apparatus or endoplasmic reticulum
Cell plate
Flattened membrane-bounded structure that forms fusing vesicles in the cytoplasm of a dividing plant cell and is the precursor of the new cell wall
Thylakoid
Flattened sac of membrane in a chloroplast that contains chlorophyll and other pigments and carries out the light-trapping reactions of photosynthesis. Stacks of thylakoids form the grana of chloroplasts.
Lamellipodium
Flattened, sheetlike protrusion supported by a meshwork of actin filaments, which is extended at the leading edge of a crawling animal cell
Cryptochrome
Flavoprotein responsive to blue light (in animals involved with circadian rhythms)
Green Fluorescent Protein
Fluorescent protein isolated from a jellyfish. Widely used as a marker in cell biology
hydrophobic force
Force exerted by the hydrogen-bonded network of water molecules that brings two non polar surfaces together by excluding water between them
Radioactive isotope
Form of an atom with an unstable nucleus that emits radiation as it decays.
Cartilage
Form of connective tissue composed of cells embedded in a matrix rich in collagen and chondroitin sulfate
Oogenesis
Formation and maturation of oocytes in the ovary
Cellularization
Formation of cells around each nucleus in a multinucleate cytoplasm, transforming it into a multicellular structure
Diplotene
Fourth stage of division of meiosis, in which chiasmata are first seen https://o.quizlet.com/o9xANefiGbB06HXFNNp-Iw_m.jpg
Cell-free system
Fractionated cell homogenate that retains a particular biological function of the intact cell and in which biochemical reactions and cell processes can be more easily studied
Standard free-energy change
Free-energy change of two reacting molecules at standard temperature and pressure when all components are present at a concentration of 1 mole per liter.
Protozoa
Free-living or parasitic, nonphotosynthetic, single-celled, motile eukaryotic organisms, such as Paramecium and Amoeba. Free-living protozoa feed on bacteria or other microorganisms.
Karyotype
Full set of chromosomes of a cell arranged with respect to size, shape and number
Acyl group
Functional group derived from a carboxylic acid. (R-C=0) R is an alkyl group
Alkyl group
Functional group of covalently linked carbon and hydrogen atoms produced by removing a hydrogen from an alkane
Fertilization
Fusion of a male and female haploid gamete to produce a diploid zygote in order to produce a new individual
Inhibitory G protein
G protein that can regulate ion channels and inhibit the enzyme adenylyl cyclase
Stimulatory G protein (Gs)
G protein that, when activated, activates the enzyme adenylyl cyclase and thus stimulates the production of cyclic AMP.
Rhodopsin
G-protein-linked light-sensitive receptor protein in the rod photoreceptor cells of the retina.
G2 phase
Gap 2 phase of the eukaryotic cell division cycle, between the end of DNA synthesis and the beginning of mitosis
G1 phase
Gap1 phase of the eukaryotic cell-division cycle, between the end of cytokinesis and DNA synthesis
Nitric oxide NO
Gaseous signal molecule in both animals, where it regulates smooth muscle contraction, and in plants, where it is involved in responses to injury or infection
Gene repressor protein
Gene regulatory protein that prevents the initiation of transcription
V gene segment
Gene segment encoding most of the variable region of the polypeptide chains of immunoglobulins and T cell receptor.
Housekeeping gene
Gene serving a function required in all the cell types of an organism regardless of their specialized role and that are being transcribed constitutively
Tumor suppressor gene
Gene that appears to prevent formation of a cancer. Loss-of-function mutations in such genes enhance susceptibility to cancer.
Virulence gene
Gene that contributes to an organism's ability to cause disease.
Cell-division-cycle gene (cdc)
Gene that controls a specific step in the eukaryotic cell cycle
Pseudogene
Gene that has accumulated multiple mutations that has rendered it inactive and nonfunctional.
rRNA gene
Gene that specifies a ribosomal RNA (rRNA).
White blood cell (leukocyte)
General name for all the nucleated blood cells lacking hemoglobin. Includes lymphocytes, neutrophils, eosinophils, basophils, and monocytes.
Respiration
General term for a process in a cell involving the oxidative breakdown of sugars or other organic molecules, and requiring the uptake of O2 while producing CO2 and H2O as waste products.
Phagocyte
General term for a professional phagocytic cell-that is, a cell such as a macrophage or neutrophil that is specialized to take up particles and microorganisms by phagocytosis.
DNA tumor virus
General term for a variety of different DNA viruses that can cause tumors
Residue
General term for the unit of a polymer. That portion of a sugar, amino acid, or nucleotide that is retained as part of the polymer chain during the process of polymerization.
Hemopoiesis
Generation of blood cells, mainly in the bone marrow
Carcinogenesis
Generation of cancer
Genotype
Genetic constitution of an individual cell or organism
Saccharomyces
Genus of yeasts that reproduce asexually by budding or sexually by conjugation. Economically important in brewing and baking, they are also widely used in genetic engineering and as simple model organisms in the study of eukaryotic cell biology.
Polytene chromosome
Giant chromosome in which the DNA has undergone repeated replication without separation into new chromosomes.
Schwann cell
Glial cell responsible for forming myelin sheaths in the peripheral nervous system.
Zona pellucida
Glycoprotein layer on the surface of the unfertilized egg. It is often a barrier to fertilization across species.
Escherichia coli
Gram-negative, facultatively anaerobic, rod-shaped bacterium commonly found on the lower intestine of warm-blooded organisms Widely used in biomedical research
Molecule
Group of atoms joined together by covalent bonds
DNA repair
Group of biochemical processes that correct damaged DNA
Imaginal disc
Group of cells that are set aside in the Drosophila embryo and which will develop into an adult structure
Erythropoietin
Growth factor that stimulates the production of red blood cells. Produced by the kidney and acts on precursor cells in bone marrow https://o.quizlet.com/i/OlYGT8sx5XS-M3Y72g9--w_m.jpg
Angiogenesis
Growth of new blood vessels by sprouting from existing ones (angeîon, "vessel") https://o.quizlet.com/guE0.pbvHLiMOA34YhDBVg_m.png
GTP
Guanosine 5'-triphosphate. Nucleoside triphosphate produced by phosphorylating GDP. It releases a large amount of free energy on hydrolysis of its terminal phosphate group. Special role in microtubule assembly, protein synthesis and cell signaling
Connexon
H2O filled pore in the plasma membrane formed by a ring of 6 protein subunits. Part of a gap junction which allows the formation of a continuous channel between two cells
Hydronium ion
H3O+ water molecule associated with an additional proton
High-performance liquid chromatography
HPLC. Type of chromatography that uses a column with tiny beads of matrix, the solution to be separated is used through under high pressure
Cillium
Hairlike extension of eukaryotic cells containing microtubules that is capable of performing repeated beating movements. Found in the cell surface and responsible for swimming of unicellular organisms
Amphipathic
Having both hydrophobic and hydrophilic region. Phospholipid or detergent molecules.
Haploid
Having only one set of chromosomes, as in a sperm cell or a bacterium
Basic
Having the properties of a base
Actin filament
Helical polymer of actin proteins (F-actin) that forms microfilaments. Forms cytoskeleton in eukaryotes.
hnRNP protein
Heterogeneous nuclear ribonuclear protein. Any of a group of proteins that assemble on newly synthesized RNA, organizing it into a more compact form
Thioester bond
High-energy bond formed by a condensation reaction between an acid (acyl) group and a thiol group (-SH); seen, for example, in acetyl CoA and in many enzyme-substrate complexes.
Mitotic chromosome
Highly condensed duplicated chromosome with the two new chromosomes still held together at the centromere as sister chromatids
Adrenaline - epinephrine
Hormone released by the adrenal gland and some neurons in response to stress. "fight or flight" (increase heart rate and blood sugar levels)
HIV
Human Immunodeficiency virus. Retrovirus that is the cause of AIDS
Alkene
Hydrocarbon joined by one or more C-C double covalent bonds
Alkane
Hydrocarbon joined by single covalent bonds
Acid hydrolase
Hydrolytic enzyme that has its optimal activity at acidic pH (~5) (proteases, nucleases, etc). Found in lysosomes
Stop-transfer signal
Hydrophobic amino acid sequence that halts translocation of a polypeptide chain through the endoplasmic reticulum membrane, thus anchoring the protein chain in the membrane.
Ethyl
Hydrophobic chemical group derived from ethane https://o.quizlet.com/i/5cdr_5ekOXXmjjg-7eziwQ_m.jpg
Methyl
Hydrophobic chemical group derived from methane https://o.quizlet.com/i/WJaEJ1qa4CAYFIqPn-4Qkg_m.jpg
Steroid
Hydrophobic lipid molecule with a characteristic four-ringed structure. Many important hormones such as estrogen and testosterone are steroids.
Elastin
Hydrophobic protein that forms elastic fibers that give tissues their stretchability and resilience
Metaphase plate
Imaginary plane at right angles to the mitotic spindle and midway between the spindle poles; the plane in which chromosomes are positioned at metaphase
Pre-B cell
Immediate precursor of a B cell.
Restriction point
Important checkpoint in the mammalian cell cycle. Passage through the restriction point commits the cell to enter S phase. It corresponds to Start in the yeast cell cycle.
Toll-like receptor family (TLR)
Important family of mammalian pattern recognition receptors abundant on macrophages, neutrophils, and the epithelial cells of the gut. They recognize pathogen-associated immunostimulants such as lipopolysaccharide and peptidoglycan.
Operon
In a bacterial chromosome, a group of contagious genes that are transcribed into a single mRNA molecule
in vivo
In an intact cell or organisms (latin for in life)
Mating-type locus
In budding yeast, the locks that determines the mating type (alpha or a) of the haploid yeast cell
Vector
In cell biology, the DNA of an agent (virus or plasmid) used to transmit genetic material to a cell or organism.
Reaction
In chemistry, any process in which one molecule is converted into another by the removal or addition of atoms, or in which the arrangement of atoms in a molecule or molecules is altered by a change in chemical bonds.
Recessive
In genetics, refers to the member of a pair of alleles that fails to be expressed in the phenotype of the organism when the dominant allele is present. Also refers to the phenotype of an individual that has only the recessive allele.
Overlap microtubule
In mitotic or meiotic single, a microtubule interdigitating at the equator with the microtubules emanating from the other pole
Module
In proteins or nucleic acids, a unit of structure or function that is found in a variety of different contexts in different molecules
Polar
In the electrical sense, describes a structure (for example, a chemical bond, chemical group, or molecule) with positive charge concentrated toward one end and negative charge toward the other as a result of an uneven distribution of electrons. Polar molecules are likely to be soluble in water.
Animal pole
In yolky eggs (embryo) the end free of yolk that consists of small cells and divides rapidly.
X-inactivation
Inactivation of one copy of the X chromosome in the somatic cells of female mammals.
Positional information
Information supplied to or possessed by cells according to their position in a multicellular organism. A cell's internal record of its positional information is called its positional value.
Transcription attenuation
Inhibition of gene expression in bacteria by the premature termination of transcription.
Microinjection
Injection of molecules into a cell using a micropipette
Inner membrane
Innermost of two membranes surrounding an organelle. In mitochondria, it carries respiratory electron transport chain
Inner nuclear membrane
Innermost of two nuclear membrane, Contains binding sites for chromatin and nuclear lamina on its internal face
Cofactor
Inorganic ion or coenzyme required for an enzyme's activity
Myelin sheath
Insulating layer of specialized cell membrane wrapped around vertebrate axons. Produced by oligodendrocytes in the central nervous system and by Schwann cells in the peripheral nervous system
Circadian clock
Internal cyclical process that produces a particular change in a cell/organism with a period of around 24 hours
Receptor-mediated endocytosis
Internalization of receptor-ligand complexes from the plasma membrane by endocytosis. It is used to take up some macromolecules, such as cholesterol-containing lipoproteins, from the extracellular fluid, and is also a means of recycling receptor proteins once they have bound their ligands.
Symbiosis
Intimate association between two organisms of different species from which both derive a long-term selective advantage.
Caspase
Intracellular proteases involved in the apoptosis cellular initiation
IAP family
Intracellular protein inhibitor in apoptosis
Nuclear receptor superfamily
Intracellular receptors for hydrophobic signal molecules such as steroids and retinoid acid. The receptor-ligand complex acts as a transcription factor in the nucleus
Transfection
Introduction of a foreign DNA molecule into a eukaryotic cell. It is usually followed by expression of one or more genes in the newly introduced DNA.
Caveola
Invaginations at the cell surface that can bud off internally to form pinocytic vesicles and form lipid rafts (regions of membrane rich lipids) https://o.quizlet.com/BGgWco7PdWo4BKD.4CaZnw_m.png
Transmitter-gated ion channel
Ion channel in the postsynaptic plasma membranes of nerve and muscle cells that opens only in response to the binding of a specific extracellular neurotransmitter. The resulting inflow of ions leads to the generation of a local electrical signal in the postsynaptic cell.
Fungus
Kingdom of eukaryotic organisms that includes the unicellular organisms of yeast and molds and multicellular organisms like mushrooms. Cause many plant diseases and some animal diseases
Low-density lipoprotein
LDL. Large complex composed of a single protein molecule and many esterified cholesterol molecules, together with other lipids. The form in which cholesterol is transported in the blood and taken up into cells
Endoplasmic reticulum
Labyrinthine membrane-bounded compartment in the cytoplasm of eukaryotic cells, where lipids are synthesized and membrane-bound proteins and secretory proteins are made
Nonpolar
Lacking any asymmetric accumulation of positive and negative charge. Generally insoluble in water
Spliceosome
Large assembly of RNA and protein molecules that performs pre-mRNA splicing in eukaryotic cells.
Pseudopodium
Large cell-surface protrusion formed by amoeboid cells are as they crawl. More generally, any dynamic actin-rich extension of the surface of an animal cell.
Ig superfamily
Large family of proteins that contain immunoglobulin domains. Most are involved in cell-cell interactions or antigen recognition
Transforming growth factor-beta superfamily (TGF-B superfamily)
Large family of structurally related, secreted proteins that act as hormones and local mediators to control a wide range of functions in animals, including during development. It includes TGF-B, activins, and bone morphogenetic proteins (BMPs).
SNAREs
Large family of transmembrane proteins present in organelle membranes and the vesicles derived from them. They are involved in guiding vesicles to their correct destinations. They exist in pairs - a v-SNARE in the vesicle membrane that binds specifically to a complementary t-SNARE in the target membrane.
Recycling endosomes
Large intracellular membrane-bounded vesicle formed from a fragment of an endosome that is an intermediate stage on the passage of recycled receptors back to the cell membrane.
Phagosome
Large intracellular membrane-bounded vesicle that is formed as a result of phagocytosis. Contains ingested extracellular material.
Polymer
Large molecule made by covalently linking multiple identical or similar units (monomers) together.
Nuclear pore complex
Large multiprotein structure forming a channel through the nuclear envelope that allows selected molecules to move between nucleus and cytoplasm
Megakaryocyte
Large myeloid cell with a multilobed nucleus that remains in the bone marrow when mature. Buds off platelets from long cytoplasmic processes
RNA polymerase II holoenzyme
Large pre-assembled complex of RNA polymerase II, most of the general transcription factors required for its function, and the mediator protein complex.
Proteasome
Large protein complex in the cytosol with proteolytic activity that is responsible for degrading proteins that have been marked for destruction by ubiquitylation or by some other means.
Origin Recognition Complex
Large protein complex that is bound to the DNA at origins of replication in eukaryotic chromosomes throughout the cell cycle
Chlorophyll
Light-absorbing green pigment that plays a central part in photosynthesis in bacteria, plants and algae
Photosynthetic electron-transfer
Light-driven reactions in photosynthesis in which electrons move along the electron-transport chain in the thylakoid membrane, generating ATP and NADPH.
Euchromatin
Lightly packed form of chromatin that is enriched in genes associated with active transcription
Phospholipase C-gamma (PLC-gamma)
Like phospholipase C-beta, an enzyme that cleaves inositol phospholipids to diacylglycerol and IP3 to trigger the inositol phospholipid signaling pathway. Activated by certain receptor tyrosine kinases.
HeLa cell
Line of human epithelial cells that grows vigorously in culture. Derived from a human cervical carcinoma
Polysaccharide
Linear or branched polymer of monosacccharides. They include glycogen, starch, hyaluronic acid, and cellulose.
Polypeptide
Linear polymer composed of multiple amino acids. Proteins are large polypeptides, and the two terms can be used interchangeably.
Cholesterol
Lipid molecule with a four-ring steroid. Important component of plasma membrane in animal cells
Diacylglycerol
Lipid produced by cleavage of inositol phospholipids in response to extracellular signals. Composed of two fatty acid chains linked to glycerol. It serves as a signaling molecule to help activate protein kinase C
Hepatocyte
Liver cell
inflammatory response
Local response of a tissue to injury or infection (tissue redness, swelling, heat, pain). Caused by an invasion of white blood cells and their release of mediators like histamine
Replication origin
Location on a DNA molecule at which duplication of the DNA begins.
Microtubule
Long hollow cylindrical structure composed of tubular. One of the three major classes of filaments of the cytoskeleton
Axon
Long nerve cell that is capable of conducting nerve impulses over long distances in order to deliver signal to other cells https://o.quizlet.com/i/Rz2MYdOt7YPmsTKaFwAJzg_m.jpg
Interphase
Long period of the cell cycle between mitosis events. Includes G1, S phase and G2 phase
Neurite
Long process growing from a nerve cell in culture. A generic term that does not specify whether the process is an axon or a dendrite
Myofibril
Long, highly organized bundle of actin, myosin, and other proteins in the cytoplasm of muscle cells that contracts by a sliding filament mechanism
Glycosaminoglycan
Long, linear, highly charged polysaccharide composed of a repeating pair of sugars, one of which is always an amino sugar. Mainly found covalently linked to a protein core in extracellular matrix proteoglycans
Flagellum
Long, whiplike protrusion whose undulations drive a cell through a fluid medium. It is used as locomotion or as a sensory organelle. Their structure and composition differs greatly in prokaryotes and eukaryotes
Long-term potentiation
Long-lasting increase in the sensitivity of certain synapses in the hippocampus. Induced by a short burst of repetitive firing in the presynaptic neurons https://o.quizlet.com/a1yEDky.nGvz3PWfLvVB-Q_m.jpg
Immunological memory
Long-lived state that follows a primary immune response to many antigens. In which subsequent encounter with that antigen will provoke a rapid secondary immune response
Oxidation
Loss of electrons from an atom, as occurs during the addition of oxygen to a molecule or when a hydrogen is removed. Opposite of reduction
Biotin
Low-molecular-weight molecule used as a coenzyme. Used to covalently label proteins for avidin detection
Peripheral lymphoid organ (secondary lymphoid organ)
Lymphoid organ in which T cells and B cells interact with foreign antigens. Examples are spleen, lymph nodes, and mucosal-associated lymphoid tissue.
Central lymphoid organ
Lymphoid organ in which lymphocytes develop. In animals this is the thymus and the bone marrow
Microtubule-associated protein
MAP. Any protein that binds to microtubules and modifies their properties, e.g. structural proteins, such as MAP-2 or motor proteins, such as dynein
Microtubule-organizing center
MTOC. Region in a cell, such as a centrosome or a basal body, from which microtubules grow
Osteoclast
Macrophage-like cell that erodes bone, enabling it to be remodeled during growth and in response to stresses throughout life
Central nervous system
Main information-processing organ of the nervous system. In vertebrates it consists of the brain and spinal cord
Cell body
Main part of a nerve cell that contains the nucleus (other parts are dendrites and axons) https://o.quizlet.com/10hETpubs7lb6cmRo7HrjQ_m.png
Septate junction
Main type of occluding cell junction in invertebrates; their structure is distinct from that of vertebrate tight junctions.
Calvin cycle
Major metabolic pathway by which CO2 is incorporated into carbohydrate during the carbon fixation photosynthesis stage in plants
Enzyme-linked receptor
Major type of cell-surface receptor in which the cytoplasmic domain ether has enzymatic activity itself or is associated with an intracellular enzyme. Enzymatic activity is stimulated by ligand binding to the receptor
Genetic map
Map of the chromosomes in which the distance of genes relative to each other is determined by the amount of genetic recombination that occurs between them
Syncytium
Mass of cytoplasm containing many nuclei enclosed by a single plasma membrane. Typically the result either of cell fusion or of a series of incomplete division cycles in which the nuclei divide but the cell does not.
Affinity constant Ka
Measure of binding strength of the components of a complex
Dissociation constant
Measure of the tendency of a complex to dissociate
Cell wall
Mechanically strong extracellular matrix deposited by a cell outside of its plasma membrane. Prominent in prokaryotes, algae, fungi and plants https://o.quizlet.com/i/i-6_WQ3lZeky3-K5ABgDig_m.jpg
Chemiosmotic coupling
Mechanism in which a pH gradient across a membrane is used to drive an energy-requiring process (ATP production of flagella rotation)
Selectin
Member of a family of cell-surface carbohydrate-binding proteins that mediate transient, Ca2+-dependent cell-cell adhesion in the bloodstream, for example between white blood cells and the endothelium of the blood vessel wall.
Isoprenoid
Member of a family of lipid molecules with a carbon skeleton based on multiple five-carbon isoprene units https://o.quizlet.com/aYMBm3VBVWrIi7JmbmZiLg_m.png
Keratin
Member of a family of proteins that form keratin intermediate filaments, mainly in epithelial cells. Found in hair, nails and feather
Dominant
Member of a pair of alleles that is expressed in the phenotype of the organism while the other allele is not, even though both are present
Archea
Members of one of the two major divisions of prokaryotes (other, bacteria)
Adenylate cyclase
Membrane bound enzyme that catalyzes ATP -> cAMP
Acetylcholine receptor
Membrane bound protein (ion channel) that when bound to acetylcholine converts that chemical signal to an ELECTRICAL one
Glycolipid
Membrane lipid molecule with a sugar residue or oligosaccharide attached to the polar headgroup
Multipass transmembrane protein
Membrane protein in which the polypeptide chain crosses the lipid bilayer more than once
Single-pass transmembrane protein
Membrane protein in which the polypeptide chain crosses the lipid bilayer only once.
Transmembrane protein
Membrane protein that extends through the lipid bilayer, with part of its mass on either side of the membrane.
Membrane transport protein
Membrane protein that mediates the passage of ions or molecules across a membrane, e.g. ion channels and carrier proteins
Plasma membrane
Membrane that surrounds a living cell.
Co-transport
Membrane transport process in which the transfer of one molecule depends on the simultaneous or sequential transfer of a second molecule
Carrier protein
Membrane transport protein that binds to a solute and transports it by undergoing several conformational changes https://o.quizlet.com/oAUyy6wGvlsvXYFRGUCvPg_m.jpg
Channel protein
Membrane transport protein that forms an aqueous pore through which a solute (e.g. ion) can pass
ABC transporter proteins
Membrane transport proteins that use ATP to transfer peptides/small molecules across membranes https://o.quizlet.com/4X3eE19WisPMDnqPoeGMwg_m.jpg
Organelle
Membrane-Enclosed compartment in a eukaryotic cell that has a distinct structure, macromolecular composition, and function (e.g. nucleus, mitochondrion, chloroplast, Golgi apparatus)
Protein translocator
Membrane-bound protein that mediates the transport of another protein across an organelle membrane.
Fas protein
Membrane-bound receptor that initiates apoptosis in the receptor-bearing cell after binding to its ligand
Mitochondrion
Membrane-bounded organelle about the size of a bacterium that carried out oxidative phosphorylation and produces most of the ATP in eukaryotic cells
Endosome
Membrane-bounded organelle in animal cells that carries newly ingested materials by endocytosis and passes many of them on to lysosomes for degradation
Lysosome
Membrane-bounded organelle in eukaryotic cells containing digestive enzymes which are typically most active at the acid pH found in the lumen of this organelle
Golgi apparatus
Membrane-bounded organelle in eukaryotic cells in which proteins and lipids transferred from the ER are modified and sorted. Site of synthesis of cell wall polysaccharides in plants and extracellular matrix glycosaminoglycans in animal cells
Secretory vesicle
Membrane-bounded organelle in which molecules destined for secretion are stored prior to release. Sometimes called secretory granule because darkly staining contents make the organelle visible as a small solid object.
Polyribosome (polysome)
Messenger RNA molecule to which are attached a number of ribosomes engaged in protein synthesis.
Citric acid cycle
Metabolic pathway found in aerobic organisms. Oxidizes acetyl groups derived from food molecules to CO2 and H2O. Occurs in mitochondria
Micron
Micrometer. Unit of measurement often applied to cells and organelles. Equal to 10^-6 m
Fluorescence microscope
Microscope designed to view material stained with fluorescent dyes. Similar to a light microscope but the illuminating light is passed through one set of filters before the specimen, to select those wavelengths that excite the dye and through another set of filters before it reaches the eye, to select only those wavelengths emitted when the dye fluoresces
Growth cone
Migrating motile tip of a growing nerve cell axon or dendrite https://o.quizlet.com/Fm6WoFFL-MXmjk6fcvxVmg_m.png
Mitochondrial precursor protein
Mitochondrial protein encoded by a nuclear gene, synthesized in the cytosol, and subsequently transported into mitochondria
MAP-kinase
Mitogen activated protein kinase that performs a crucial step in relaying signals fro the plasma membrane to the nucleus. Turned on by a wide range of proliferation or differentiation-inducing signals
Molecular weight
Molecular mass of a molecule. The sum of the mass of each atom multiplied by the number of atoms of each particular element that makes up the molecule
Nucleoside
Molecule composed of a purine or pyrimidine base covalently linked to a ribose or deoxyribose sugar
AMP
Molecule composed of an adenine, ribose and one phosphate group. One of the four nucleotides in an RNA molecule.
Triacylglycerol (Triglyceride)
Molecule composed of three fatty acids esterified to glycerol. The main constituent of fat droplets in animal tissues (where the fatty acids are saturated) and of vegetable oils (where the fatty acids are mainly unsaturated).
Proteoglycan
Molecule consisting of one or more glycosaminoglycan (GAG) chains attached to a core protein.
Amide
Molecule containing a carbonyl group linked to an amine
Amine
Molecule containing nitrogen and hydrogen. + in water
Ester
Molecule formed by condensation reaction of an alcohol group with an acidic group. Phosphate groups usually form esters when linked to a second molecule https://o.quizlet.com/MgGM0nY0ce4BqTQNNKVWOA_m.jpg
Substrate
Molecule on which an enzyme acts.
Tracer
Molecule or atom that has been labeled either chemically or radioactively so that it can be followed in a biochemical process or readily located in a cell or tissue.
Macromolecule
Molecule such as a protein, nucleic acid, or polysaccharide with a molecular mass greater than a few 1000 daltons
Electron carrier
Molecule such as cytochrome c, which transfers an electron from a donor molecule to an acceptor molecule
Fluorescent dye
Molecule that absorbs light at one wavelength and responds by emitting light at another wavelength. The emitted light is of longer wavelength (and hence lower energy) that the light absorbed
Aromatic
Molecule that contains a carbon ring and single and double bonds
Electron donor
Molecule that easily gives up an electron, becoming oxidized in the process
Antigen
Molecule that provokes an immune response
Isomers
Molecules that are formed by the same atoms in the same chemical linkage but with different three dimensional conformation
Ran
Monomeric GTPase present in both cytosol and nucleus that is required for the active transport of macromolecules into and out of the nucleus through nuclear pore complexes. Hydrolysis of GTP and GDP is thought to provide the energy required for this transport.
ARF protein
Monomeric GTPase responsible for regulating COPI and clathrin coat assembly at Golgi membranes https://o.quizlet.com/i/GyMQYcugL04uecqwMBLDvw_m.jpg
Myoblast
Mononucleated, undifferentiated muscle precursor cell. A skeletal muscle cell is formed by the fusion of multiple myoblasts. Myo = muscle, blast = immature