General Biology

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General Biology
2012-10-05 17:45:19

General Biology flash cards
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  1. Cell Biology
    The study of individual cells and their interactions with each other.
  2. Cell Theory
    A theory that states that all organisms are made of cells, cells are smallest units of living organisms, and new cells come from preexisting cells by cell division.
  3. Microscope
    A magnification tool that enables researches to study very small structures such as cells.
  4. Micrograph
    An image taken with the aid of a microscope
  5. Resolution
    In microscopy, the ability to observe two adjacent objects as distint from one another; a measure of the clarity of an image.
  6. Contrast
    In microscopy, relative differences in the lightness, darkness, or color between adjacent regions in a sample.
  7. Magnification
    The ratio between the size of an image produced by a microscope and a sample's actual size.
  8. Light Microscope
    A microscope that utilizes light for illumination.
  9. Electron Microscope
    A microscope that uses an electron beam for illumination.
  10. Transmission Electron Microscope (TEM)
    A type of microscope in which a beam of electrons is transmitted through a biological sampleto form an image on a photographic plate or screen.
  11. Scanning Electron Microscopy (SEM)
    A type of microscopy that utilizes an electron beam to produce an image of the three-dimenational surface of biological samples.
  12. Protien-Protien Interactions
    The specific interactions between proteins that occur during many critical cellular processes.
  13. Genome
    The complete genetic composition of a cell or a species.
  14. Genes
    A unit of heredity that contributes to the characteristics or traits of an organism. At the molecular level, a gene is composed of organized sequences of DNA.
  15. Prokaryotes
    Refers to organisms having cells lacking a membrane-eclosed nucleus and cell comparmentalization; includesall members of the domains Bacteria and Archaea
  16. Bacteria
    (singular bacterium) when not capitalized, refers to a cell or species withing the domain Bacteria.
  17. Archaea
    One of the three domains of life; the other two are Bacteria and Eukarya
  18. Plasma Membrane
    The biomembrane that separates the internal contents of a cell from its external enviornment.
  19. Cytoplasm
    The region of the cell that is contained withing the plasma membrane.
  20. Nucleoid Region
    A site in a acterial cell where the genetic material (DNA) and ribonucleic acid (RNA).
  21. Ribosomes
    A structure composed of proteins and rRNA that provides the site where polypeptide synthesis occurs.
  22. Cell Wall
    A relatively rigid, porous, structure located outside the plasma membrane of prokaryotic, plant, fungal and certain protist cells; provides support and protection.
  23. Glycocalyx
    • 1. An outer viscous covering surrounding a bacterium that traps water and helps protect bacteria from drying out.
    • 2. A carbohydrate-rich zone on the surgace of animal cells; also called a cell coat.
  24. Capsule
    A very thick, gelatinous glycocalyx produced by certain strains of bacteria that may help them aboid being destroyed by an animal's immune (defense) system.
  25. Pili
    Threadlike surface appendages that allow prokaryotes to attach to each other during mating or to move across surfaces.
  26. Flagella
    Relatively long cell appendages that facilitate cellular movement or the movement of extracellular fluids.
  27. Eukaryotes
    One of the two categories into which all forms of life can be placed. The distinguishing feature of eukaryotes is cell comparmentalization, including a cell nucleus; includes protists, fungi, plants, and animals.
  28. Organelle
    A subcellular structure or membrane bound compartment with its own unique structure and function.
  29. Compartmentalization
    A characteristic of eukaryotic cells in which many organelles separate the cell into different regions. Cellular compartmentalization allows a cell to carry out specialized chemical reactions in different places.
  30. Proteome
    The complete complement of proteins that a cell or organism can make.
  31. Cytosol
    The region of a eukaryotic cell that is inside the plasma membrane and outside the organelles.
  32. Metabolism
    The sum total of all chemical reactions that occur within an organism. Also, a specific set of chemical reactions occurring at the cellular level.
  33. Enzyme
    A protein that acts as a catalyst to speed up a chemical reaction in a cell.
  34. Catabolism
    A metabolic pathway that results in the breakdown of larger molecules into smaller molecules. Such reactions are often exergonic.
  35. Anabolism
    A metabolic pathway that results in teh synthesis of cellular molecules and macromolecules; requires an input of energy.
  36. Cytoskeleton
    In eukaryotes, a network of three different types of protein filaments in the cytosol called microtubules, intermediate filaments and actin filaments.
  37. Microtubules
    A type of hollow protein filament composed of tubulin proteins that is part of the cytoskeleton and is important for cell shape, organization and movement.
  38. Intermediate Fillaments
    A type of prtein filament of the cytoskeleton that helps maintain cell shape and rigidity.
  39. Actin Filaments
    A think type of protein filament composed of actin proteins that forms part of the cytoskeleton and supports the plasma membrane; plays a key role in cell strngth, shape and movement.
  40. Dynamic Instability
    The oscillation of a single microtubule between growing and shortening phases; important in many cellular activities, including the sorting of chromosomes during cell division.
  41. Centrosome
    A single structure often near the cell nucleus of eukaryotic cells that forms a nucleating site for the frowth of microtubules; also called the microtubules-organizing center.
  42. Centrioles
    A pair of structures within the centrosome of animal cells. Most plant cells and many protists lack centrioles.
  43. Motor Proteins
    A category of cellular proteins that uses ATP as a source of energy to promote movements; consists of three domains called the head, hinge and tail.
  44. Cilia
    Cell appendages that have the same internal structure as flagella and funcation like flagella to facilitate cell movement; cilia are shorter and more numberous on cells than are flagella.
  45. Axoneme
    The internal structure of eukaryotic flagella and cilia consisting of microtubules, the motor protein dynein, and linking proteins.
  46. Basal Bodies
    A site at the base of flagella or cilia from which microtubules grow. Basal bodies are anchored on the cytosolic side of the plasma membrane.
  47. Nucleus
    • 1. In cell biology, an organelle found in eukaryotic cells taht contains most of the cell's genetic material.
    • 2. In chemistry, the region of an atom that contains protons and neutrons.
    • 3. In neurobiology, a group of neuronal cell bodies in the brain that are devoted to a particular function.
  48. Endomembrane System
    A network of membranes that includes the nuclear envelope, the endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, and plasma membrane.
  49. Vesicles
    A small membrane enclosed sac within a cell.
  50. Nuclear Envelope
    A double-membrane structure that encloses the cells nucleus.
  51. Nuclear Pores
    A passageway for the movement of molecules and macromolecules into and out of the nucleus; formed where the inner and outer nuclear membranes make contact with each other.
  52. Chromosome
    A discrete unit of genetic material compsed of DNA and associated proteins. Eukaryotes have chromosomes in their cell nuclei and in plastid and mitochondria.
  53. Chromatin
    Refers to the biochemical composition of chromosomes, which contain DNA and many types of protiens.
  54. Nuclear Matrix
    A filamentous network of proteins that is found inside the nucleus and lines the inner nuclear membrane. The nuclear matrix serves to organize the chromosomes.
  55. Chromosome Territory
    A distinct, nonoverlapping area where each chromosome is located within the cell nucleus of eukaryotic cells.
  56. Nucleolus
    A prominent region in the nucleus of nondividing cells where ribosome assembly occurs.
  57. Endoplasmic Reticulum (ER)
    A convoluted network of membranes in a cells cytoplasm that forms flattened, fluid-filled  tubules or cisternae.
  58. Cisternae
    Flattened, fluid-filled tubules of the endoplasmic reticulum.
  59. Lumen
    The internal space of an organelle.
  60. ER Lumen
    A single compartment enclosed by the ER membrane
  61. Rough ER
    The part of the ET that is studded with ribosomes; this region plays a key role in teh initial synthesis and sorting of proteins that are destined for the ET, Golgi apparatus, lysosomes, vacuoles, plasma membrane or outside of the cell.
  62. Glycosylation
    The attachment of carbohydrate to a prtein or lipid, producing a glycoprotein or glycolipid.
  63. Smooth ER
    The part of the ER that is not studded with ribosomes. This region is continuous with the rough ET and funcations in diverse metabolic processes such as detoxification, carbohydrate meabolism, accumulation of calcium ions, and synthesis and modification of lipids.
  64. Golgi Apparatus
    A stack of flattened, membrane bound compartments that performs three overlapping funcations: secretion, processing and protein sorting.
  65. Proteolysis
    A processing event within a cell in which enzymes called proteases cut proteins into smaller polypeptides
  66. Proteases
    An enzyme that cuts proteins into smaller polypeptides.
  67. Secretory Vesicles
    A membrane vesicle carrying different types of materiels that fuses with the cell's plasma membrane to release the contents extracellularly.
  68. Secratory Pathway
    A pathway for the movement of larger susstances, such as carbohydrates and proteins, out of a cell.
  69. Exocytosis
    A process in which material inside a cell is packaged into vesicles and excreted into the extracellular medium.
  70. Endocytosis
    A process in which the plasma membrane invaginates or folds inward to form a vesicle that brings sustances into the cell.
  71. Pulse-Chase Experiments
    A procedure in which researchers administer a pulse of radioactively labeled materials to cells so that they make radioactive products. This is followed by the addition of nonlabeled materials called a chase.
  72. Vacuole
    Specialized compartments found in eukaryotic cells that function in storage, the regulation of cell volume, and degradation.
  73. Lysosomes
    A small organelle found in animal cells that contains acid hydrolases that degrade macromolecules.
  74. Acid Hydrolases
    A hydrolytic enzyme found in lysosomes that functions at acidic pH and uses a molecule of water to break a covalent bond.
  75. Central Vacuole
    An organelle that often occupies 80% or more of the cell volume of plant cells and stores a large amound of water, enzymes, and inorganic ions.
  76. Tonoplast
    The membrane of the central vacuole in a plant or algal cell.
  77. Contractile Vacuoles
    A small, membrane enclosed, water-filled compartment that eliminates excess liquid from the cells of certain protists.
  78. Phagocytic Vacuoles/ Food Vacuoles
    A cavuole that functions in the degradation of food particles or bacteria; also called a food vacuole.
  79. Peroxisomes
    A relatively small organelle found in all eukaryotic cells that catalyzes detoxifying reactions.
  80. Catalase
    An enzyme within peroxisomes that breaks down hydrogen peroxide to water and oxygen gas.
  81. Glyoxysomes
    A specialized organelle within plant seeds that contains enzymes needed to convert fats to sugars.
  82. Membrane Transport
    The movement of ions or molecules across a cell membrane.
  83. Cell Signaling
    A vital funcation of the plasma membrane that involves cells sensing changes in their enviornment and communicating with each other.
  84. Cell Adhesion
    A vital function of the cell membrane that allows cells to bind to each other. Cell adhesion is critical in the formation of multicellular organisms and provides a way to convey positional information between neighboring cells.
  85. Mitochondrion
    A semiautonomous organelle found in eukaryotic cells that supplies most of a cell's ATP
  86. Cristae
    Projections of the highly invaginated inner membrane of a mitochondrion.
  87. Mitochondrial Matrix
    A compartment inside the inner membrane of a mitochondrion.
  88. Photosynthesis
    The process whereby light energy is captured by plant, algal, or bacterial cells and is used to synthesize organic molecules from CO2 and H2O
  89. Thylakoid Membrane
    A membrane within the chloroplast that forms many flattened, fluid filled tubules that enclose a single, convoluted compartment. It contains chlorophyll and is the site where the light-dependent reactions of photosynthesis occurs.
  90. Granum
    A structure composed of stacked membrane-bound thylakoids within a chloroplast.
  91. Stroma
    The fluid-filled region of the cloroplast between the thylakoid membrane and the inner membrane.
  92. Thylakoid Lumen
    The fluid-filled compartment within the thylakoid.
  93. Plastids
    A general name fiven to organelles found in plant and algal cells that are bound by two membranes and contain DNA and large amounts of either chlorophyll (in chloroplasts), carotenoids (in chromoplasts) or starch (in amyloplasts).
  94. Proplastids
    Unspecialized structures that form plastids
  95. Mitochondrial Genome
    The chromosome found in mitochondria
  96. Chloroplast Genome
    The chromosome found in chloroplasts
  97. Nuclear Genome
    The chromosomes found in the nucleus of a eukaryotic cell.
  98. Binary Fission
    The process of cell division in bacteria and archaea in which one cell divides into two cells.
  99. Endosymbiosis
    A symbiotic relationship in which the smaller species- the symbiont- lives inside the larger species.
  100. Endosybiosis Theory
    A theory that mitochondria and chloroplasts originated from bacteria that took up residence within a primordial eukaryotic cell.
  101. Sorting Signals/ Traffic Signals
    A short amino acid sequence in a protein that directs the protein to its correct location; also known as a traffic signal.
  102. Cotranslational Sorting
    The sorting process in which the synthesis of certain eukaryotic proteins begins in the cytosol and then halts temporarly until the ribosome has become bound to the ER membrane.
  103. Post-Translational Sorting
    The uptake of proteins into the nucleus, mitochondria, chloroplasts, or peroxisomes that occurs after the protein is completlely made in the cytosol (that is, completely translated)
  104. ER Signal Sequence
    A sorting signal in a polypeptide usuallly located near the amino terminus that is recognized by SRP (signal recognition particle) and directs the polypeptide to the ER membrane
  105. Signal Recognition Particle (SRP)
    A protein/RNA complex that recognizes the ER signal sequence of a polypeptide, pauses translation, and directs the ribosome to the ER to complete translation.
  106. Coat Proteins
    A protein that surrounds a membrane vesicle and facilitates vesicle formation.
  107. V-Snare
    A protein incorporated into a vesicle formation that is recognized by a t-snare in a target membrane.
  108. T-Snare
    A protien in a target membrane that recognizes a v-snare in a membrane vesicle.
  109. Chaperones
    A protein that keeps other proteins in an unfolded state during the process of post-translational sorting
  110. Systems Biology
    A field of study in which researchers investigate living organisms in term of their underlying networks-groups of structuresand functional connections- rather than their individual molecular components
  111. Endomembrane System
    A network of membrane that includes the nuclear envelope, the endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, and plasma membrane.
  112. Semiautonomous Organelles
    Includes the Mitochondria and chloroplasts
  113. Plasma Membrane
    The biomembrrane that seperates the internal contents of a cell from its external enviornment.
  114. Phospholipid Bilayer
    The basic framework of the cellular membrane, consisting of two layers of lipids.
  115. Amphipathic
    Molecules containng a hydrophobic (water-fearing) region and a hydrophilic (water-loving) region.
  116. Fluid-Mosaic Model
    The accepted model of the plasma membrane; its basic framework is the semifluid phospholipid bilayer with a mosaic of proteins. Carbohydrates may be attached to the lipids or proteins.
  117. Leaflet
    • 1. Half of a phospholipid bilayer
    • 2. A portion of a compound leaf.
  118. Integral Membrane Protein
    A protein that cannot be released from the membrane unless it is deissolved with an organic solvent or detergent. Includes transmembrane proteins and lipid anchored proteins.
  119. Transmembrane Protein
    A protein that has one or more regions that are physically embedded in the hydrophobic region of a cell membrane's phospholipid bilayer.
  120. Transmembrane Segments
    A region of a membrane protein that is a strech of noonpolar amino acids that spans or traverses that membrane from one leaflet to the other.
  121. Lipid-Anchored Proteins
    A type of integral membrane protein that is attached to the membrane via a lipid molecule.
  122. Peripheral Membrane Proteins
    A protein that is oncovalently bound to regions of intergral membrane proteins that project out from the membrane, or they are nonvovalently bound ot the polar head groups of phospholipids.
  123. Semifluid
    A quality of motion within biomembranes; considered two-dimentional because movement occurs only within the plane of the membrane.
  124. Fluidity
    A property of biomembranes in which individual moleules remain in close association yet have the ability to move rotationally or laterally within the plane of the membrane. Membranes are semifluid.
  125. Lipid Raft
    In a membrane, a group of lipids and proteins that float together as a unit in a larger sea of lipids.
  126. Unsaturated
    The quality of a lipid containing one or more C=C double bonds.
  127. Glycosylation
    The attachment of carbohydrate to a protein or lipid, producing a glycoprotein or glycolipid.
  128. Glycolipid
    A lipid that has carbohydrate attached to it.
  129. Glycoprotein
    A protein that has carbohydrate attached to it.
  130. Cell Coat/ Glycocalyx
    • 1. An outer viscous covering surrounding a bacterium that traps water and helps protect bacteria from drying out.
    • 2. A carbohydrate-rich zone on the surface of animal cells; also called a cell coat.
  131. Lipid Exchange Proteins
    A protein that extracts a lipid from one membrane, diffuses through the cell, and inserts the lipid into another membrane.
  132. Membrane Transport
    The movement of ions or molecules across a cell membrane.
  133. Selectively Permeable
    The property of membranes that allows the passage of certain ions or molecules but not others.
  134. Diffusion
    In a sollution, the process that occurs when a solute moves from a region of high concentration to a region of lower concentration.
  135. Facilitated Diffusion
    A method of passive transport that involves the aid of a transport protein.
  136. Passive Transport
    The diffusion of a solute across a membrane in a process that is energetically favorable and does not require an input of energy.
  137. Active Transport
    The transport of a solute across a membrane against its gradient (from a region of low concentration to a region of higher concentration). Active transport requires an input of energy.
  138. Transmembrane Gradient
    A situation in which the concentration of a solute is highter on one side of a membrane than on the other.
  139. Electrochemical Gradient
    The combined effect of both an electrical and chemical gradient across a membrane;  determines the direction that an ion will move
  140. Isotonic
    Condition in which the solute concentrations on both sides of a plasma membrane are equal, which does not cause a cell to shrink or swell.
  141. Hypertonic
    Any solution that causes a cell to shrink due to osmosis of water out of the cell.
  142. Hypotonic
    Any solution that causes a cell to swell when placed in that solution.
  143. Osmosis
    The movement of water across membranes to balance solute concentrations. Water diffuses from a solution that is hypotonic (lowers solute concentrations)  into a solution that is hypertonic (higher solute concentration).
  144. Osmotic Lysis
    Occurs when a cell in a hypotonic enviornment takes up so much water that it ruptures.
  145. Crenation
    The process of cell shrinkage that occurs if animal cells are placed in a hypertonic medium.
  146. Plasmolysis
    The shrinkage of algal or plant cytoplasm that occurs when water leaves the cell by osmosis, with the result that the plasma membrane no longer presses on the cell wall.
  147. Osmotic Pressure
    The hydrostatic pressure required to stop the net flow of water across a membrane due to osmosis.
  148. Aquaporin
    A trransport protein in the form of a channel that allows the rapid diffusion of water across the cell membrane.
  149. Transport Proteins
    Proteins embedded within the phosphlipid bilayer that allow plasma membranees to be selectively permeable by providing a passageway for teh movement of some but not all sustances across the membrane.
  150. Channels
    A transmembrane protein that forms an open passageway for the direct diffusion of ions or molecules across a membrane.
  151. Gated
    A property of many channels that allows them to open and close to control the diffusion of solutes through a membrane.
  152. Transporter/ Carriers
    A membrane protein that binds a solute and undergoes a conformational change to allow the movement of the solute across a membrane; also called a carrier.
  153. Uniporters
    A type of transporter that binds a single ion or molecule and transports it across across a membrane.
  154. Symporters/ Contransporters
    A type of transporter that binds two or more ions or molecules and transports them in the smae direction across a membrane; also called a cotransporter
  155. Antiporters
    A type of transporter that binds two or more ions or molecules and transports them in opposite directions across a membrane.
  156. Primary Active Transport
    A type of transport that involves pumps that directly use energy to transport a solute against a gradient.
  157. Pump
    A transporter that directly couples its conformational changes to an energy source, such as ATP hydrolysis.
  158. Secondary Active Transport
    A type of membrane transport that involves the utilization of a preexisting gradient to drive the active transport of another solute.
  159. Electogenic Pump
    A pump that generates an electrical gradient across a membrane.
  160. Exocytosis
    A process in which material inside a cell is packaged into vesicles and excreted into the extracellular medium.
  161. Endocytosis
    A process in which the plasma membrane invaginates, or folds inward, to form a vesicle that brings substances into the cell.
  162. Receptor-Mediated Endocytosis
    A common form of endocytosis in which a receptor is specific for a given cargo.
  163. Pinocytosis
    A form of endocytosis that involves the formation of membrane vesicles from the plasma membrane as a way for cells to internalize the extracellular fluid.
  164. Phagocytosis
    A form of endocytosis that involves the formation of a membrane vesicle, called a phagocytic vacuole, which engulfs a particle such as a bacterium.
  165. Multicellular
    Describes an organism consisting of more than one cell, particularly when cell-to-cell adherence and signaling processes and cellular specialization can be demonstrated.
  166. Extracellular Matrix (ECM)
    A network of material that is secreted from animal cells and forms a complex meshwork outside of cells. The ECM provides strength, support, and organization.
  167. Strength
    The EMC is the "tough stuff" of animals' bodies. In the skin of mammals, the strength of the ECM prevents tearing. The ECM found in cartilage resists compression and provides protection to the joints. Similarly, the ECM protects the soft parts of the body, such as the internal organs.
  168. Structural Support
    The bones of many animals are composed primarily of ECM. Skeletons not only provide structural support but also facilitate movement via the functioning of attached muscles.
  169. Organization
    The attachment of cells to the ECM plays a key role in the proper arrangement of cells throughout the body. IN addition, the ECM binds many body parts together, such as tendons to bones.
  170. Cell Signaling
    A newly discovered role of the ECM is cell signaling. One way that cells in multicellular organnisms sense their environment is via changes in the ECM.
  171. Collagen
    A protein secreted from animal cells that forms large fibers in the extracellular matrix.
  172. Elastin
    A protein that makes up elastic fibers in the extracellular matrix of animals.
  173. Glycosaminoglycans (GAGs)
    The most abundant type of polysaccharide in the extracellular matrix (ECM) of animals, consisting of repeating disaccharide units that give a gel-like character to the ECM of animals.
  174. Proteoglycans
    A glycosaminoglycan in the extracellular matrix linked to a core protein.
  175. Chitin
    A tough, nitrogen-containng polysaccharide that forms the exteranl skeleton of many insects and the cell walls of fungi.
  176. Cell Wall
    A relativly rigid, porous structure located ouside the plasma membrane of prokaryotic plant, fungal, and certain protist cells; provides support and protection.
  177. Primary Cell Wall
    In plants, a relatively thin and flexible cell wall that is synthesized first between two newly made daughter cells.
  178. Cellulose
    The main macromolecule of the primary cell wall of plants and many algea; a polymer made of repeating molecules of glucose attached end to end.
  179. Cell Junctions
    Specialized structures that adhere cells to each other and to the ECM
  180. Anchoring Junction
    A type of junction between animal cells that attaches cells to each other and to the extracellular matrix (ECM).
  181. Cell Adhesion Mollecules (CAMs)
    A vital function of the cell membrane that allows cells to bind to each other. Cell adhesion is critical in the formation of multicellula organisms and provides a way to convey positional information between neighboring cells.
  182. Adherens Junctions
    Connects cells to each other via cadherins. In many cases, these junctions are organized into bands around cells. In the cytosol, adherens junctions bind to cytoskeletal filaments called actin fillaments.
  183. Desmosomes
    Connect cells to each other via cadherins. They are spotlike points of intercelular contact that rivet cells together. Desmosomes are connected to cytoskeletal filaments called intermediate filaments.
  184. Hemidesmosomes
    Connect cells to the extracellular matrix via integrins. Like desmosomes, they interact within intermediate filaments.
  185. Focal Adhesion
    Connect cells to the extracellular matrix via integrins. IN the cytosol, focal adhesions bind to actin filaments.
  186. Cadherins
    A cell adhesion molecule found in animal cells hat promotes cell-to-cell adhesion.
  187. Integrins
    A cell adhesion molecule found in animal cells that connects cells to the extracellular matrix.
  188. Tight Junctions
    A type of junction between animal cells that forms a tight seal between adjacent epithelial cells and thereby prevents molecules from leaking between cells; also called an occluding junction.
  189. Gap Junction
    A type of juntion between animal cells that provides a passageway for intercellular transport
  190. Connexon
    A channel that forms fap juntions consisting of six connexin proteins in one cell aligned with six connexin proteins in an adjacent cell.
  191. Middle Lamella
    An extracellular layer in plants composed primarily of carbohydrate; cements adjacent plant cell walls together.
  192. Plasmodemata
    A membrane-lined, ER-containing channel that connects the cytoplasm of adjacent plant cells.