BioTest1StudyGuide

Scientists are often under pressure to produce

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Unformatted text preview: ) What types of activities are considered to be scientific misconduct? What leads scientists to these actions? Why do they most often get caught? Fabrication, falsification, and plagiarism. Scientists are often under pressure to produce results in order to get more grant money for their research. Also, sometimes scientists have conflicts of interest because they are being paid by a company to do research. They most often get caught when others try to replicate their research, and they can’t get the same results. What distinguishes one atom from another? number of protons What is the atomic number of an atom? the number of protons in an atom What is an ion? atom which has gained or lost an electron and therefore has a charge (+ or -) An isotope? 7 form of an atom with different number of neutrons A radioactive isotope? atoms with too many or too few neutrons, making them unstable and causing them to decay (give off atomic particles or radiation) What is the half-life of a radioisotope? the time it takes for 1/2 of the atoms of a radioactive material to disintegrate How does carbon dating work? What does it tell us? In carbon dating, the decay of carbon-14 is used to estimate the age of organic materials. It tells us how old a once-living organism is. What are free radicals? Anti-oxidants? Free radicals are atoms with unpaired electrons that can damage proteins and DNA. They can be neutralized by antioxidants like Vitamin A, C and E, and Beta-carotene. What determines the chemical reactivity of an atom? The chemical reactivity of an atom is dependent on the arrangement of electrons. The electron shell that is particularly important in determining how an atom will, or will not bond with another atom is the outermost shell, called the valence shell. What are the different types of chemical bonds? The differences between them? How are they formed? Which are stronger and which are weaker? Where is each type found? Where is each type important? ● Ionic Bond- bond in which one or more electrons from one atom are removed and attached to another atom, resulting in positive and negative ions which attract each other. ● Covalent Bond- bond in which one or more pairs of electrons are shared by two atoms. ● Polar Covalent Bond- Covalent bonds in which the sharing of the electron pair is unequal, with the electrons spending more time around the more nonmetallic atom- In such a bond there is a charge separation with one atom being slightly more positive and the other more negative, i.e., the bond will produce a dipole moment. ● Hydrogen bond- a force of attraction between a hydrogen atom in one molecule and a small atom of high electronegativity in another molecule. Hydrogen bonding has a very important effect on the properties of water and ice. Hydrogen bonding is also very important in proteins and nucleic acids and therefore in life processes. The "unzipping" of DNA is a breaking of hydrogen bonds which help hold the two strands of the double helix together. What is pH? What is an acid? A base? Why does it matter? pH is the logarithmic scale that describes the acidity (H+ concentration) of a solution. An acid is a chemical substance that donates H+ ions to solutions. A base is a compound that accepts...
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This test prep was uploaded on 03/16/2014 for the course BIO 101 at Wake Forest.

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