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Chemical Basis For Life

Subject : engineering
Instructions:
  • Answer 50 questions in 15 minutes.
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  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Any of 116 known substances that cannot be separated into smaller substances; the smallest unit of this is an atom.






2. Threadlike accumulations of DNA in the nuclei of cells that are particularly visible during mitosis. The DNA contains the genetic material of the cell.






3. This trace element is a critical component of hemoglobin; without adequate amounts of this element - animals develop anemia.






4. Any ionic copmound composed of positively charged cations and negatively charged anions so that the product is electrically neutral.






5. Fatty acids in which not all chemical binding sites of the molecules are filled with hydrogen; contain one or more double bonds and are liquid at room temperature. Usually plant in origin.






6. The rate at which radioactive isotopes emit energy; used to determine the age of artifacts found on archeological digs.






7. A simple sugar - such as glucose or fructose - that has six carbon atoms per molecule.






8. A compound composed of a carbohydrate - usually in the form of a sugar - and a protein.






9. Anything that has mass and exists as a solid - liquid or gas.






10. Any of a group of substances derived from 20- carbon unsaturated fatty acids - such as arachidonic acid; includes prostaglandins - leukotrienes - and thromboxanes. They are the principle mediators of inflammation.






11. The main component of triglycerides present in all fats; triglycerides are soluble in water and alcohol.






12. Subatomic particles with a positive charge that - along with neutrons - make up the entire mass of the nucleus; number of these defines the atomic number.






13. Phosphate bonds in ADP and ATP containing large amounts of energy; when the bond is broken - the energy becomes available to do cellular work.






14. Substances that dissolve in water to yield hydroxyl ions and give the solution a pH greater than 7.






15. Lipids characterized by a carbon skeleton that contains four fused rings; cholesterol is an example.






16. An eicosanoid produced by platelets that causes vasoconstriction and promotes the clumping of platelets.






17. An eicosanoid formed from the activation of white blood cells; act to sustain inflammation in asthmatic and allergic reactions.






18. A substance that minimizes the change of the acidity of a solution when an acid or base is added to the solution.






19. This major element is the primary component of organic molecules.






20. Reactions that break down more complex materials into simpler ones by adding water; water molecules are consumed in the reaction.






21. The tendency of a tissue to absorb or be attracted to water; water- loving.






22. An unstable isotope of an element that decomposes spontaneously by emission of subatomic particles and radiation.






23. The organic compounds of hydrogen - oxygen - and carbon that - when mixed with glycerol - form fat; may be saturated - unsaturated - or volatile.






24. Chains of more than 10 amino acids.






25. Abbreviation for adenosine triphosphate.






26. Fatty acids with no double bonds in their carbon chains; can accomodate the maximum number of hydrogen atoms. Typically in animal fats and solid at room temperature.






27. The smallest unit of an element having all the characteristics of that element.






28. Chemical messenger of the body produced and excreted by specific cells for the purpose of regulating specific organs or cells.






29. Substance that induces chemical reactions by lowering the activation energy needed; e.g. - heat - enzymes.






30. A molecule that contains both a lipid and a protein; often function as transmembrane proteins to move substances across the cell membrane or as transport proteins in the blood.






31. Substance that is dissolved in another substance; the component of a solution that is present in the lesser amount.






32. The combination of phosphoric acid - pentose sugars - and pyrimidine or purine bases that make up nucleic acids.






33. The number of protons found in the nucleus of an atom; in a neutrally charged atom - the atomic number is also the number of electrons.






34. A substance in which another substance is dissolved; water is the universal solvent.






35. A molecule composed of three parts: phosphorous - fatty acids and glycerol; major component of cell membranes.






36. A chemical reaction in which elements or simple molecular reactants are combined into a more complex product; the opposite of a decomposition reaction.






37. The group of fatty or fatlike substances that are insoluble in water; can dissolve in alcohol - ether - chloroform - and other nonpolar substances.






38. The smallest particle of a substance composed of two or more atoms that retains the properties of the substance.






39. This minor element is an important positive ion in extracellular fluid and is important in nerve funciton.






40. The average mass of an atom of an element; equal to the number of protons and neutrons in the nucleus.






41. This trace element is a key component of thyroid hormone; without this element - the thyroid gland cannot make its hormone - resulting in a swelling called goiter.






42. A dense region at the center of an atom consisting of positively charged protons and uncharged neutrons.






43. A subatomic particle with no electrical charge that joins with the protons to make up the entire mass of the nucleus.






44. The tendency of a tissue to be repelled by water or to be insoluble; water- fearing.






45. A force by which atoms are bound in a molecule: covalent bonds - ionic bonds - and hydrogen bonds.






46. A chemical reaction in which chemical substances exchange molecules or elements to form different chemcial substances; a combination of decomposition and synthesis reactions.






47. A type of chemical bond formed by the electrostatic attraction between two oppositely charged atoms or molecules (ions).






48. A chemical reaction in which a complex reactant is divided into simpler molecules or elements; the opposite of a synthesis reaction.






49. The force between two particles of opposite electrical charge.






50. A substance made up of two or more elements.