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9 Cards in this Set
- Front
- Back
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What is a covalent bond?
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-strongest bond resulting from the sharing of electrons b/t adjacent atoms
-approx. 1.5 A long and 350-850 KJ -come in single or double bonds with resonance -establish configuration and sequence of biological polymers |
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What is an ionic bond?
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-strong interaction b/t chemicals and has a long range
-E= K(q1q2)/(D x R) <- equation to determine energy interaction b/t 2 charges |
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What are hydrogen bonds?
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-strong bond that has a H donar and acceptor
-has optimal length and angle, yet very flexible -donor to acceptor= 2.4-3.5 A and 4-10 KJ/mol |
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What is a hydrogen bond donor?
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-electronegative atom with a hydrogen bonded to it
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What is a hydrogen bond acceptor?
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-an electronegative atom witha lone pair of atoms
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What are van der Walls interactions?
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-arises friom correlated fluctuations in electron densities of atoms
-weak and short ranged -2-4 KJ/ atom pair -becomes significant when large number of atoms are in contact |
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What is the hydrophobic effect?
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-a speciaql property of water as a solvent
-molcules in water aggregate to reduce surface area -main driving force of protein folding and acid-base stacking |
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How does the structure of DNA result from weak interactions?
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-neg. charged phosphates are on outside and bonds on backbone are extended
-puts neg,. charges far apart -phosphates and sugars hydrogen bond w/ water -hydrophobic bases are on the inside -H-bonding contributes to base-pair specificity, not stability |
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What is heat?
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-form of energy that corrsponds to a kinetic energy (motion) of molcules
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