BIO 1201 Test 1

BIO 1201 Test 1 - The upper temperature for life is 130*C...

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The upper temperature for life is 130*C Cell and body temperatures can range from - 2*C-130*C and pressure ranges from 1atm-1100atm. The average depth of the ocean is 2*-4*C body temperatures and approximately -380atm with no sunlight @ 3.8km. Organisms confront a variety of problems due to their environment: Antarctic fishes live at -2*C and are ectotherms meaning their body temperature is determined by their environments temperature . Fish accumulate antifreeze molecule (proteins to prevent freezing to death) Penguins keep warm at cold temperatures. They are endotherms meaning they set their own body temperature through metabolism . Diving seals can hold their breath up to 90 minutes in depths of 1500m.
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Deep sea fishes can go down to 7000m with high pressure, cold temperatures and low food availability. Barophiles- bacteria piezophiles are pressure loving ; they thrive at pressure that kills surface bacteria. Thermophiles- bacteria exist at temperatures up to 130* and grow up till 121*. Sharks- live with ½ molar used in their tissues to match the osmotic strength of the sea water -their urea denatures proteins Halophiles- bacteria that live in osmotic equilibrium with 3 molar salt Tuna raise the temperature of their muscles above ambient (above their environment) as much as 15*C. They are endotherms. Gutless Tubeworms thrive at deep sea hydrothermal vents.
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Midwater fish and invertebrates- organisms living in the water column achieve natural buoyancy despite the high density of biological materials Elements- pure substances which cannot be broken down to simpler substances - there are 92 naturally occurring elements and 103 total Atom - the smallest unit an element can be divided into and retain its identity -neutrons (neutral charge) and protons (+1 charge) make up the nucleus -electron has a-1 charge and essentially no mass Atomic number = number of protons in the nucleus Atomic mass = number of protons + neutrons Ion- number of neutrons does not equal number of protons Compound- A substance that can be broken down to two or more elements 1. The composition of a compound is always the same ; definite and exact 2. When elements combine to form compounds energy is either liberated or absorbed 3. Elements lose their individual identity when they combine to form a compound. The compound has a new set of characteristics. 4. A compound is homogenous (versus a mixture). Chemical Bonds- forces holding atoms together in molecules - characterized as being weak or strong depending on the amount of energy needed to make or break the bond - strong bonds are known as covalent when atoms share electrons - Weak bonds are non-covalent - Ionic interactions - attraction of opposite charges and one atom donates an electron to another -Hydrogen bonds (an atom of slightly negative charged is attracted to an atom of slightly positive charge)
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Valence is the number of electrons needed to fill the outer shell. Valence electrons
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This note was uploaded on 10/12/2010 for the course BIOL 1201 taught by Professor Wishtichusen during the Spring '07 term at LSU.

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BIO 1201 Test 1 - The upper temperature for life is 130*C...

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