AP Biology Unit 1 Test Question and answers rated A+

AP Biology Unit 1 Test Question and answers rated A+water -polar molecule -polar colvalent bonds -oxygen end is partial negative and the hydrogens have a partially positive end -cohesive polar covalent bonds -opposite ends of the molecule have opposite charges cohesion -H bonding between H2O creates it (sticky) -allows for the movement of water against gravity -high surface tension -water moves up a tree by transpiration (helped by ____) adhesion -H2O molecules form H bonds with other substances ~capillary action ~meniscus ~water climbs up fiber solvent -water is the universal one -polar water molecules will surround the (+) and (-) ions causing the ions to separate and dissolve -dissolve solutes and create aqueous solutions hydrophilic -some molecules have an affinity for water -polar and ionic molecules -ex: cotton, cellulose, paper hydrophobic -some substances do not have an affinity for water -nonpolar and non ionic substances -ex: fat, glycerol, oils floats -less dense when it is solid, water ______ -forms crystal lattice structure -important because oceans and lakes do not freeze solid ~insulates water below ~seasonal turnover of lakes specific heat -the amount of heat that must be absorbed or lost for 1g to change its temperature by 1C -water had high _____ due to H bonding -resists change in temp -moderates temp on earth evaporative cooling -organisms use to regulate their temperature -ex: sweating -water evaporates through a surface, cooling occurs acidic If [H+]>[-OH] basic If [-OH]>[H+] pH scale -how acidic or basic a solution is -pure water, only 1 molecule in every 554 million is dissociated -most biological fluids have 6-8 -each unit represents a 10-fold difference in H+ and -OH concentrations neutral -If concentration of 2 ions is equal carbon -all life mostly based on this element -important due to its electron configuration ~able to make 4 stable covalent bonds (tetra valence) ~very versatile -tetravalence allows them to be strung together in chains hydrocarbons -combinations of C and H -nonpolar ~not soluble in water ~hydrophobic -stable -very little attraction between molecules -gas at room temp isomers -molecules with the same molecular formula but different structures -different chemical properties -different biological functions structural isomers -differ in covalent arrangement of atoms geometric isomers -same covalent relationships by different spatial arrangements enantiomers -isomers that are mirror images of each other -structural differences create important functional significance functional groups -substitute other elements for hydrogen -parts of organic molecules that are involved in chemical reactions -give organic molecules distinctive properties -affect reactivity ~make hydrocarbons hydrophilic ~increase solubility in water macromolecules -by joining carbon to other elements, we form the basis of life -smaller organic molecules join together to form larger molecules polymer -a long molecule consisting of similar or identical building blocks -blocks known as monomers -joined through covalent bonds -dehydration synthesis synthesis -joins monomers by "taking" H2O out -one monomer donates -OH -other monomer donates H+ -together these form H2O -requires energy and enzymes -condensation reaction digestion -use H2O to breakdown polymers -reverse of dehydration synthesis -cleave off one monomer at a time -H2O is split into H+ and -OH -requires enzymes -releases energy -hydrolysis carbohydrates -composed of C, H, O -function: energy, raw materials, energy storage, and structural storage -monomer: sugars sugars -all have carbonyl group and multiple hydroxyl groups -location determines whether it is an aldehyde or ketone -most names end in -ose -classified by number of carbons -when in solution, 5C and 6C structures form rings monosaccarides -simple one monomer sugars -ex: glucose disaccharides -2 monomer sugars -ex: sucrose polysaccharides -large polymer sugars -ex: starch sugar polymers -costs little energy to build -easily reversible=release energy -function: energy storage (starch in plants and glycogen in animals) and structure (cellulose in plants and chitin in arthropods and fungi) starch vs. cellulose -differ in the position of the hydroxyl group on Carbon 1 -S____ has an alpha configuration (normal bonding of glucose monomers) -C________ has a beta configuration (every other glucose monomer is upside down) -causes differences in organisms' ability to digest it (S easy, C hard) cellulose -major component of plant walls -most abundant organic compound on Earth -herbivores have evolved a mechanism to digest it -most carnivores have not evolved -undigested roughage lipids -functions: long term energy storage and concentrated energy, cushions organs, and insulates body -not a true polymer and not large enough to be a macromolecule -big molecules made up of smaller subunits -not a continuous chain -all mix poorly in water (hydrophobic) -include waxes, pigments, fats, pils, phospholipids, and steroids -structure: a glycerol (3 Carbons) and a fatty acid chain triacylcglycerol (triglyceride) -three fatty acid chains linked to a glycerol -combine by an Ester linkage (hydroxyl and carboxyl) -dehydration synthesis saturated fats -all carbons are bonded to hydrogens -there are no carbon to carbon double bonds -long, straight chain -most animals fats -solid at room temp. (contributes to cardiovascular disease, atherosclerosis) unsaturated fats -contains carbon to carbon double bonds in the fatty acids -C=C double bonds in the fatty acids -plant and fish fats -vegetable oils -liquid at room temp (the kinks made by double bonded C prevent the molecules from packing tightly together) -mono- and poly- phospholipids -structure: glycerol + 2 fatty acids + PO4 (negatively charged) -contains a head and a tail region -fatty acids tails are hydrophobic -PO4 head is hydrophilic -in water, assembles into a bubble (forms a bilayer) -create a barrier for water and define "outside" vs. "inside" -make up the cell membrane steroids -structure: carbon skeleton of four fused rings with different chemicals attached -with a different functional group attached you create a new one -ex: cholesterol and sex hormones cholesterol -important cell component -animal cell membranes -helps keep membrane fluid, flexible and mobile -precursor of all other steroids ~including vertebrate sex hormones -high levels in blood may contribute to cardiovascular disease proteins -most structurally and functionally diverse group -function: involved in almost everything ~enzymes (pepsin, DNA polymerase) ~structure (keratin, collagen) ~carriers and transport (hemoglobin, aquaporin) ~cell communication (signals and receptors) ~defense (antibodies) ~movement (actin and myosin) ~storage (bean seed) -structure: ~monomer amino acids ~polymer polypeptide -can be one or more polypeptide chains folded and bonded together -large and complex molecules -complex 3D shape amino acids -structure: central carbon (alpha carbon) -amino group -carboxyl group (acid) -R group (side chain) ~variable group ~different for each ~confers unique chemical properties -physical and chemical properties based on R groups attached peptide bonds -covalent bond between NH2 (amine) of one amino acid and COOH (carboxyl) of another -C-N bond