Science terms starting with P

1,062 terms

  1. Pronuclear injection The use of a fine needle to inject DNA into the nucleus of an unfertilized egg.
  2. Pronucleus Either of the two haploid gamete nuclei just prior to their fusion in the fertilized ovum.
  3. Proof A measure of ethanol content. 1-percent ethanol content equals 2 proof.
  4. proofreading The scanning of newly-synthesized DNA for structural defects, such as mis-matched base pairs. A functional activity of most DNA polymerase s.
  5. PROPA Propagation (movement)
  6. propagation The duplication of a whole plant from a range of vegetative materials; adapted for in vitro culture as micropropagation.
  7. propagule Any structure capable of giving rise to a new plant by asexual or sexual reproduction, including bulbils, leafbuds, etc.
  8. Propane A hydrocarbon gas, C3H8, occurring in crude oil, natural gas, and refinery cracking gas. It is used as a fuel, a solvent, and a refrigerant.
  9. Propeller (Hydro) Turbine A turbine that has a runner with attached blades similar to a propeller used to drive a ship.
  10. Property Protection Measures that are undertaken usually by property owners in order to prevent, or reduce flood damage.
  11. prophase The first stage of nuclear division. The stage during which occurs in the first division of meiosis (see: leptonema, zygonema, pachynema, diplonema…
  12. Proratable water That portion of the total water supply available under provisions of sections 18 and 19 of Civil Action No.
  13. prostate cancer (PROS-tayt KAN-ser) Cancer that forms in tissues of the prostate (a gland in the male reproductive system found below the bladder and in front of the…
  14. protamine A class of small basic proteins that replace the histones in the chromosomes of some sperm cells.
  15. protease An enzyme that cleaves peptide bonds that link amino acids in protein molecules.
  16. Protection For purposes of the National System of MPAs, must have existing laws or regulations that are designed and applied to afford the site with increased…
  17. Protective Action An action or measure taken to avoid or reduce exposure to a hazard.
  18. Protective action decision making (recommendations) The process whereby local authorities select one of more actions to protect threatened populations.
  19. protein (PRO-teen) A molecule made up of amino acids that are needed for the body to function properly.
  20. protein crystallization The production of a pure preparation of a protein. In this form, the three-dimensional structure of the molecule can be determined.
  21. protein drug See: therapeutic agent.
  22. protein engineering Generating proteins with modified structures that confer novel properties such as higher catalytic specificity or thermal stability.
  23. Protein kinase An enzyme that adds phosphate groups to a protein molecule at serine, threonine, or tyrosine residues.
  24. protein metabolic step One step in the chain of reactions that take place in an organism and dictate the composition of that organism.
  25. protein sequencing The process of determining the amino acid sequence of a protein. Usually achieved following initially partial hydrolysis of the protein into smaller…
  26. protein synthesis The creation of proteins from their constituent amino acid s, in accordance with the encoding gene DNA sequence.
  27. proteinaceous infectious particle Believed to be the agent responsible for the class of diseases called spongiform encephalopathies, including scrapie in sheep, bovine spongiform…
  28. Proteinaceous infectious particle (prion) A proposed pathogen composed only of protein with no detectable nucleic acid and which is responsible for Creutzfeldt-Jakob disease and kuru in humans and…
  29. proteolysis Enzymatic degradation of a protein.
  30. Proteolytic The ability to break down protein molecules.
  31. Proteome The complete complement of proteins made by a given species in all its tissues and growth stages.
  32. proteomics The study of the structure and function of proteins, including the way they work and interact with each other inside cells.
  33. Proto-oncogene See oncogene.
  34. protoclone Regenerated plant derived from protoplast culture or a single colony derived from protoplasts in culture.
  35. protocol An action plan for a clinical trial. The plan states what the study will do, how, and why.
  36. protocorm A tuberous structure, formed following the germination of orchid seeds, from which develops a complete plant.
  37. protoderm A primary that gives rise to epidermis.
  38. protogyny The condition in which the female reproductive organs (carpel s) of a flower mature before the male ones (stamen s), thereby ensuring that…
  39. protomeristem See: pro-meristem.
  40. Proton A small, positively charged particle of matter found in the atoms of all elements.
  41. Proton Event In solar-terrestrial terms, the measurement of at least 10 protons/cm2/sec/steradian at energies greater than 10 MeV.
  42. Proton Flare In solar-terrestrial terms, any flare producing significant fluxes of greater-than-10 MeV protons in the vicinity of the earth.
  43. protoplasm The essential, complex living substance of cells, upon which all vital functions of nutrition, secretion, growth and reproduction depend.
  44. protoplast A bacterial or plant cell for which the cell wall has been removed either chemically or enzymatically, leaving its cytoplasm enveloped by a peripheral…
  45. protoplast culture The culturing in vitro of plant protoplast s. Where protoplasts can be regenerated into whole plants, they represent an attractive target for genetic…
  46. protoplast fusion The induced or spontaneous coalescence of two or more protoplast s of the same or different species origin.
  47. prototroph A nutritionally independent cell. Opposite: auxotroph.
  48. Protozoan Single-celled organism that can perform all necessary functions of metabolism and reproduction.
  49. protruding end See: extension.
  50. provenance The geographical and/or genetic origin of an individual.
  51. Provirus See virus.
  52. Proximate Analysis A commonly used analysis for reporting fuel properties; may be on a dry (moisture free) basis, as "fired", or on an ash and moisture free basis.
  53. Proxy If you own common stock in a US corporation, you have the right to vote on certain company policies and elect the board of directors by casting a proxy…
  54. PRST Persist
  55. PRVD Provide
  56. PSBL Possible
  57. PSBLY possibly
  58. PSD increments The maximum increases in ambient pollution concentrations allowed over baseline concentrations for a pollutant while ensuring that an area continues to…
  59. pseudo-affinity chromatography A chromatographic technique in which a ligand is immobilized selectively to retain enzymes or other protein s.
  60. pseudo-autosomal region A section at one end of the X and Y chromosomes for which there is sufficient homology that there is synapsis between them during meiosis.
  61. Pseudo-Cold Front A boundary between a supercell's inflow region and the rear-flank downdraft (or RFD).
  62. Pseudo-Warm Front A boundary between a supercell's inflow region and the forward-flank downdraft (or FFD).
  63. pseudocarp A fruit that incorporates, in addition to the ovary wall, other parts of the flower, such as the receptacle (e.g. strawberry). Synonym: false fruit.
  64. pseudogene An incomplete or mutated copy of a gene which is not transcribed because it lacks a continuous open reading frame.
  65. Pseudomonas spp. A widely distributed Gram-negative bacterial genus. Many of the soil forms produce a pigment that fluoresces under ultraviolet light, hence the…
  66. PSG Passage
  67. Psi Pounds of pressure per square inch.
  68. Psia Pounds/force per square inch absolute.
  69. Psig Pounds/force per square inch gauge.
  70. PST Please Send Tell. Indicates that the person speaking wants to receive communication via a /t(ell) or /w(hisper) command.
  71. Psychological value. See Social value.
  72. Psychrometer An instrument for measuring relative humidity by means of wet and dry-bulb temperatures.
  73. Psychrometric tables Psychrometric tables Tables prepared from the psychrometric formula and used to obtain vapor pressure, relative humidity, and dew point from wet- and…
  74. Psychrometrics The analysis of atmospheric conditions, particularly moisture in the air.
  75. psychrophile A micro-organism that can grow at temperatures below 30 °C and as low as 0 °C. See: mesophile, thermophile.
  76. PTCHY Patchy
  77. PTCLDY Partly Cloudy
  78. PTDY On a buoy report, Pressure Tendency is the sign (plus or minus) and the amount of pressure change (hPa) for a three hour period ending at the time of…
  79. PTLY Partly
  80. PTN Portion
  81. PTTN pattern
  82. PTWC (Pacific Tsunami Warning Center) - The Pacific Tsunami Warning Center in Ewa Beach (pronounced Eva Beach), HI has an international warning responsibility…
  83. PTYPE precipitation type
  84. Public affairs officer The dam operating organization's designated person responsible for public affairs.
  85. Public Alert and Notification System The system for obtaining the attention of the public and providing appropriate emergency information.
  86. Public Health Service Act See Food and Drug Administration.
  87. Public information officer (public relations officer) The person on the emergency management team who is in charge of public information affairs.
  88. Public Information Statement A narrative statement issued by a National Weather Service Forecast Office that can be used for: 1) A current or expected nonhazardous event of general…
  89. Public involvement Process of obtaining citizen input into each stage of development of planning documents. Citizen input is required in all environmental impact statements.
  90. Public involvement plan Document that presents the procedural plans of the Bureau of Reclamation to inform and gather information from project beneficiaries and the general…
  91. Public land Any land and interest in land (outside of Alaska) owned by the United States and administered by the Secretary of the Interior through the Bureau of Land…
  92. Public land order An action on Federal lands to withdraw it from public use for a specified purpose.
  93. Public Land Order (PLO) An order affecting, modifying, or cancelling a withdrawal or reservation that has been issued by the Secretary of the Interior pursuant to powers of the…
  94. Public Land Survey System (PLSS) The survey carried out by the BLM and its predecessors for establishing boundaries and subdivisions of public lands of the United States, using the rules…
  95. Public Severe Weather Outlook These are issued when the Storm Prediction Center (SPC) in Norman, Oklahoma anticipates an especially significant and/or widespread outbreak of severe…
  96. Public Utilities Commission (Public Service Commission) The state regulatory agency that governs retail utility rates and practices and, in many cases, issues approvals for the construction of new generation…
  97. Public Utilities Regulatory Policy Act (PURPA) of 1978 A law that requires electric utilities to purchase electricity produced from qualifying power producers that use renewable energy resources or are…
  98. Public utility commissions State agencies that regulate investor-owned utilities operating in the state.
  99. Public utility district (PUD) A publicly owned energy producer or distributor. PUDs operate as special government districts under the authority of elected commissions.
  100. Public Utility Holding Company Act (PUHCA) Federal legislation, enacted in 1935, which regulates the corporate structure and financial operations of certain utility holding companies.