National Academies Press: OpenBook
« Previous: References
Suggested Citation:"Glossary." National Research Council. 1990. The Search for Life's Origins: Progress and Future Directions in Planetary Biology and Chemical Evolution. Washington, DC: The National Academies Press. doi: 10.17226/1541.
×
Page 135
Suggested Citation:"Glossary." National Research Council. 1990. The Search for Life's Origins: Progress and Future Directions in Planetary Biology and Chemical Evolution. Washington, DC: The National Academies Press. doi: 10.17226/1541.
×
Page 136
Suggested Citation:"Glossary." National Research Council. 1990. The Search for Life's Origins: Progress and Future Directions in Planetary Biology and Chemical Evolution. Washington, DC: The National Academies Press. doi: 10.17226/1541.
×
Page 137
Suggested Citation:"Glossary." National Research Council. 1990. The Search for Life's Origins: Progress and Future Directions in Planetary Biology and Chemical Evolution. Washington, DC: The National Academies Press. doi: 10.17226/1541.
×
Page 138

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Glossary A: Angstrom; unit of length. achondrite: Differentiated meteorite. anticodon: Triplet of bases in transfer RNA complementary to the codon. archaebacteria: Organisms constituting one of the three biological king- doms. Archean: Period of Earth's history from 3.8 to 2.4 billion years ago. arc see: Arc second; unit of angular measurement in astronomy. ATF: Astrometric telescope facility. AU: Astronomical unit; mean distance between the Earth and the Sun. biogenic elements: Elements making up the bulk of living organisms. CAI: Calcium-aluminum inclusion, found in meteorites. carbonaceous chondrite: Meteorite with granules containing carbon-rich matter. CCD: Charge coupled device. CIT: Circumstellar Imaging Telescope. cm: Centimeter. codon: Triplet code of bases in DNA specifying an amino acid in protein synthesis. COMPLEX: Committee on Planetary and Lunar Exploration. CRAF: Comet Rendezvous Asteroid Flyby mission. Cretaceous: Period of Earth's history from 145 to 65 million years ago. D/H: Deuterium-to-hydrogen ratio. DNA: Deoxyribonucleic acid. DOE: Department of Energy. 135

136 ECHO: Evolution of Complex and Higher Organisms; report. EIRP: Effective isotropic radiated power. ESA: European Space Agency. eubacteria: All other bacteria besides the archaebacteria. eukaryote: Cells with true nucleus and other internal organelles. GLOSSARY FGS: Fine guidance sensor. FIRST: Far-Infrared Space Telescope. Fischer-Tropsch reaction: Process in which carbon monoxide and hydro- gen mixtures are converted into hydrocarbons and related compounds. FOS: Faint object spectrograph. genome: The complete set of genes in an organism. GHz: Gigahertz; unit of frequency. HD/H2: Ratio of deuterated hydrogen to hydrogen. heterocyclic organic polymers: Compounds consisting of monomeric units of organic ring molecules in which not all atoms in the rings are alike. heterotroph: Organism requiring organic compounds as food source. HIMS: Hubble imaging Michelson spectrometer. IR: Infrared region of electromagnetic spectrum. IRAS: Infrared Astronomical Satellite. ISO: Infrared Space Observatory. ISOCAM: Infrared Space Observatory camera. I: Joule; unit of heat energy. K: Kelvin; unit of temperature. KAO: Kuiper Airborne Observatory. L183: Interstellar cloud. LDR: Large deployable reflector. m: Meter. MAP: Multichannel astrometic photometer. MHz: Megahertz; unit of frequency. MIPS: Multiband imaging photometer for SIRTF. mRNA: Messenger RNA; directs the synthesis of proteins. NAB: Nicotinamide adenine dinucleotide; coenzyme involved in redox reactions. NASA: National Aeronautics and Space Administration.

GLOSSARY 137 NICMOS: Near-infrared camera and multiobject spectrometer. NIH: National Institutes of Health. NMR: Nuclear magnetic resonance. NRAO: National Radio Astronomy Observatory. NRC: National Research Council. NSF: National Science Foundation. nucleoside: Precursor of nucleic acids; consists of an organic base and a sugar. nucleosynthesis: Production of elements heavier than hydrogen. oligonucleotide: Short chain of nucleic acid monomers. Oligopeptide: Short chain of amino acids. PAH: Polyaromatic hydrocarbon. Paleozoic: Period in Earth's history from 670 to 245 million years ago. Permian: Period of Earth's history from 285 to 245 million years ago. Phanerozoic: Period of Earth's history from 670 million years ago to present. phenotype: Observable physiological behavior of an organism. phosphomonoesterase: Hydrolytic enzyme; releases inorganic phosphate. pllototroph: Organism deriving its energy from light. phylogeny: Ordering of biological species based on their evolutionary relationships. planetesimal: Solar-system body; of the order of a kilometer in size. planetoid: Solar-system body; tens to hundreds of kilometers in size. prebiotic: Before the appearance of life on Earth. Precambrian: Period of Earth's history from its formation to 600 million years ago. prokaryote: Organism lacking a true nucleus. Proterozoic: Period of Earth's history from 2.5 billion to 600 million years ago. pyrolysis: Destruction of organic compounds by combustion. regolith: Surface debris on solar-system objects produced by impacting bodies. RFI: Radio frequency interferences. ribonucleotide: Monomeric unit of RNA. ribooligonucleotide: Short chain of ribonucleotides. ribosome: Cellular particle; site of protein synthesis. RNA: Ribonucleic acid. RNA polymerase: Enzyme that polymerizes ribonucleotides. RNase P: tRNA-processing enzyme containing a catalytic RNA subunit. rRNA: Ribosomal RNA; involved in protein synthesis.

38 GLOSSARY S.: Svedberg unit; sedimentation constant used in ultracentrifugation. SAO: Smithsonian Astrophysical Observatory. SETI: Search for extraterrestrial intelligence. SIRTF: Space Infrared Telescope Facility. SNC: Shergottite, nakhlite, and chassignite meteorites; possibly from Mars. SSB: Space Science Board/Space Studies Board. T4 RNA ligase: Enzyme causing ribonucleic acid fragments to join to- gether. template: Molecule that is copied to form its complement in nucleic acid synthesis. thiol ester: Sulfur-containing ester. TMC-1: Interstellar cloud. translation: Process by which DNA code specifies sequencing of amino acids. tRNA: Transfer RNA; combines with specific amino acid in protein syn- thesis. . . UV: Ultraviolet region of electromagnetic spectrum. Van der Waals force: Weak attractive force between nonpolar molecules. Viking: U.S. mission to Mars in 1975. W: Watt; unit of power. WFC: Wide-field camera.

Next: Appendix »
The Search for Life's Origins: Progress and Future Directions in Planetary Biology and Chemical Evolution Get This Book
×
Buy Paperback | $50.00
MyNAP members save 10% online.
Login or Register to save!
Download Free PDF

The field of planetary biology and chemical evolution draws together experts in astronomy, paleobiology, biochemistry, and space science who work together to understand the evolution of living systems.

This field has made exciting discoveries that shed light on how organic compounds came together to form self-replicating molecules--the origin of life.

This volume updates that progress and offers recommendations on research programs--including an ambitious effort centered on Mars--to advance the field over the next 10 to 15 years.

The book presents a wide range of data and research results on these and other issues:

  • The biogenic elements and their interaction in the interstellar clouds and in solar nebulae.
  • Early planetary environments and the conditions that lead to the origin of life.
  • The evolution of cellular and multicellular life.
  • The search for life outside the solar system.

This volume will become required reading for anyone involved in the search for life's beginnings--including exobiologists, geoscientists, planetary scientists, and U.S. space and science policymakers.

  1. ×

    Welcome to OpenBook!

    You're looking at OpenBook, NAP.edu's online reading room since 1999. Based on feedback from you, our users, we've made some improvements that make it easier than ever to read thousands of publications on our website.

    Do you want to take a quick tour of the OpenBook's features?

    No Thanks Take a Tour »
  2. ×

    Show this book's table of contents, where you can jump to any chapter by name.

    « Back Next »
  3. ×

    ...or use these buttons to go back to the previous chapter or skip to the next one.

    « Back Next »
  4. ×

    Jump up to the previous page or down to the next one. Also, you can type in a page number and press Enter to go directly to that page in the book.

    « Back Next »
  5. ×

    To search the entire text of this book, type in your search term here and press Enter.

    « Back Next »
  6. ×

    Share a link to this book page on your preferred social network or via email.

    « Back Next »
  7. ×

    View our suggested citation for this chapter.

    « Back Next »
  8. ×

    Ready to take your reading offline? Click here to buy this book in print or download it as a free PDF, if available.

    « Back Next »
Stay Connected!