Biology 1201 Test 1 Biology 1201 Test 1 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 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 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 Midwater fish and invertebrates organisms living in the water column achieve natural buoyancy despite the high density of biological materials The more difficult something is the more important it turns out The more difficult something is the more important it turns out being being 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 transfer of electron from one atom to another a single electron in outer shell donates to one with 7 valence electrons NaCl has negative charge Valence is the number of electrons needed to fill the outer shell Valence electrons are the number or electrons in the outer shell For example Oxygen has 6 valence electrons and 2 valences Ionic Bonds weak bonds Covalent Bonds strong bonds share electrons to complete valence shell Polar bonds unequal sharing of electrons Hydrogen bonds weak non covalent bonds Between partially and partially charges H bonding effectively makes water a larger molecule In ice a water molecule interacts with exactly 4 other H2O molecules In liquid water only interacts with an average of 3 6 or fewer other molecules can be made and broken quickly Major categories weak and strong Major categories not based on of electrons False Polar bonds result from the transfer of electrons between atoms Water 70 90 of weight of most life forms sets the lowest temperature limits for life it probably doesn t set the highest temperature for life however important role in structures and properties of biological molecules water is a biological molecule Unusual properties 1 Result from Hydrogen bonds 2 Behave as a much larger molecule 3 High heat capacity 4 High heat of vaporization 5 High heat of fusion 6 Most dense at 4 C 7 High dielectric nonconducting substance insulator 8 Capillary action ability of a substance to draw another to it and surface tension 9 Ionization turning an atom into an ion by adding or removing charged particles 1 Amount of heat necessary to raise the temperature of 1g of water by 1 C 1 cal per g of H2O 2 Amount of heat to vaporize 1g of water 540 cal per g at 100 C 3 Amount of heat removed to freeze 1g of water 80 cal per g 4 Because of Hydrogen bonding structure ice is lighter than water this is why lakes don t freeze on the bottom 5 Good Solvent 6 Water transfer in plants is due to hydrogen bonding 7 Ionization dissociation into acid hydronium ion and base hydroxyl ion pH 10g 1 H 10g H the difference between pH 3 and pH 4 is ten fold difference in the concentration of H in pH3 and pH5 is 100 fold pH7 is neutral below 7 is an acid above 7 is a base as pH decreases by 1 unit H concentration increases ten fold Biological Molecules 1 Water 2 Carbohydrates 3 Lipids 4 Proteins 5 Nucleic Acids Functional Groups 1 Hydroxyl alcohols OH 2 Carbonyl Aldehydes Ketones CO 3 Carboxyl Acids COOH 4 Amino Amines NH2 5 Sulfhydryl thiols SH 6 Phosphates organic phosphates OPO3 2 Biological Molecules Large molecules are constructed by smaller molecules polymers constructed by monomers Synthesis of Polymers Condensation dehydration synthesis proceeds with the removal of a water molecule Hydrolysis breaking the covalent bond of the polymer by adding a water molecule Why make large biological molecules from smaller ones 1 Flexible 2 It takes fewer enzymes to make biological enzymes than if starting from scratch Carbohydrates CH2O monosaccharides linear or in a ring play an important role in energy C6H12O6 Metabolic fuel storage form starch plants glycogen humans Structural roles cellulose in plants support the structure Chitin in animals polymer of glucose structured protein Lipids water insoluble organic biological molecules made up of nonpolar groups water doesn t react well structural components of cell membranes Store and transport forms of fuel protective surface coating waxy Cell component in cell recognition Hormone steroid Advantages of Lipids over Carbs
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