BIO 121 Exam 1questions and correct answers solutions guaranteed success.

True - correct answers True or False: nothing in science is proven well substained explanation of something in the natural world that can incorporate facts, laws, hypothesises etc - correct answers Theory gravity is factual, there is a vast body of knowledge that explains the facts of gravity facts, inferences, laws, tested hypothesis - correct answers Gravitational Theory facts. evolution itself is factual. inferences, laws evolution accounts for the unity and diversity of life - correct answers Evolutionary theory new properties emerge at each level in biological hierarchy result from arrangement of parts in an ecosystem/community - correct answers emergent properties what chemical element it is - correct answers number of protons determines: same element, different number of neutrons - correct answers isotopes determine chemical properties lose, gain, or share to fill valence shell - correct answers valence shells 8 except H and He (2) - correct answers how many electrons are needed to fill a valence shell? sand, glass - correct answers silicon dioxide compounds - correct answers atoms are joined by chemical bonds to form: gives type and relative number of atoms in sequence - correct answers chemical formula outer shells of atoms have joined. strong and stable. atoms share valence electrons - correct answers covalent bonds if electrons are shared equally - correct answers Nonpolar if electrons are not shared equally (H2O) if one element is more electronegative than the other - correct answers polar form between positive (cations) and negative (anions) strong w/o presence of water but weak in aqueous solution (because water has + and - charges) - correct answers ionic bonds relatively weak. form when hyd. atom w/ partial positive is attracted to atom w/ partial negative - correct answers hydrogen bonds proteins nucleic acids carbohydrates lipids - correct answers 4 main classes of biological molecules amino acids - correct answers Monomer of proteins enzymes- catalyze chemical reactions structural/transport proteins help w/ cells - correct answers what do proteins do nucleotides - correct answers monomer of nucleic acids code for genetic info - correct answers what do nucleic acids do monosaccharides - correct answers monomer of carbohydrates storage for glucose - correct answers what do carbs do fatty acids and glycerol - correct answers monomer of lipids form cell membranes - correct answers what do lipids do form up to four covalent bonds single, double, or triple bonds straight, branched, or rings bond with many different elements - correct answers carbon atoms different covalent arrangements ethanol C2H60 - correct answers structural isomers different spatial arrangements - correct answers geometric isomers mirror images - correct answers enatiomers long chains of monomers often linked via condensation reactions - correct answers Polymers large polymers (polysaccharides, protein, DNA) often broken down by hydrolysis - correct answers Macromolecules cohesion - correct answers water exhibits _________ because it forms hydrogen bonds with itself adhesion - correct answers water molecules exhibit __________ by hydrogen bonding to substances with ionic or polar regions specific heat hydrogen bonds must break to raise water temperature - correct answers water has a high s____________ h________ organisms maintain constant internal temperature stabilize the temperature of large bodies of water (oceans). this greatly affects climate - correct answers specific heat of water helps: vaporization. hydrogen bonds must break for molecules to enter vapor phase molecules carry heat, causing evaporative cooling - correct answers water has a high heat of _____________ less dense than liquid water - correct answers hydrogen bonds between water molecules make ice: proton doners (H+) dissociate in solution to yield H+ and an anion - correct answers acids proton acceptors dissociate in solution to yield hydroxide ions (OH-) - correct answers bases one carbon, two hydrogen one oxygen composed of sugar subunits!!!! (monosaccarides) which can be linked into polysaccarides monosaccharides polysaccharides disaccharides - correct answers Carbohydrates starch in plants, glycogen in animals - correct answers Storage polysaccharides cellulose, cell walls of plants chitin, cell walls of fungi and exoskeletons - correct answers Structural polysaccharides fats/oils glycerol and three fatty acids saturated or unsaturated - correct answers Lipids main storage fat - correct answers triacylglycerol structure: glycerol, 2 fatty acids, phosphate function: cell membrane component water attracts to hydrophilic heads - correct answers Phospholipids carbon atoms arranged in 4 rings cholesterol, bile salts, some hormones - correct answers steroids polypeptides 20 amino acids long linear polymers joined by peptide bonds ex: enzymes, proteins (structural, storage, transport, regulatory, motile, protective) - correct answers Proteins 3-D shape, conformation, quaternary/tertiary structure (((shape))) - correct answers What aspect of a protein determines its function? linear sequence of amino acids - correct answers Primary strucuture regular conformation, fold up and loop hydrogen bonds between amino acids - correct answers Secondary overall shape of polypeptide chain chemical interactions of side chain - correct answers Tertiary tertiary chains combined - correct answers Quaternary made of nucleotides nitrogenous base (2 ring purine or 1 ring pyrimidine), phosphate group, sugar (ribose or deoxyribose) - correct answers Nucleic Acids cytosine (DNA and RNA), thymine (DNA only), uracil (RNA only) - correct answers Pyrimidines Adenine and Guanine - correct answers Purines adenosine triphosphate essential in energy metabolism - correct answers ATP electron acceptor in biological oxidation and reduction reactions - correct answers NAD+ long chains of nucleotides store and transfer information -sequence of amino acids in proteins -structure and function of an organism - correct answers DNA and RNA net movement of substances down their concentration gradient from high concentration to low concentration does not use direct metabolic energy!!!! - correct answers Diffusion amphipathic hydrophobic fatty acid tail, hydrophilic head - correct answers phospholipid molecules fluid!!!! (fluid mosaic model) physically separates interior from exterior of cell receives info about changes in environment regulates passage of materials in and out of cell communicates with other cells forms compartments to allow separate functions participates in biochemical reactions - correct answers Plasma membrane selectively permeable membranes that help maintain homeostasis in the cell - correct answers biological membranes embedded in bilayer extend completely thru membranes - correct answers integral membrane/transmembrane proteins at surface of bilayer bound to exposed integral proteins - correct answers peripheral protiens allows passage of some substances - correct answers semi-permeable membranes