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71 Cards in this Set
- Front
- Back
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Matter
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Anything that occupies space and has mass
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Elements
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substances that cannot be broken down by ordinary chemical means
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Major Elements of the body
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Carbon, Hydrogen, ocygen, and nitrogen make up roughly 96% of body weight
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Atoms
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the smallest particles of an element
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Atomic Symbol
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One or two letter chemical shorthand, usually the first letter of the elements name
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Atomic Structure
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each atom has a central nucleus with positively charged protons, negatively charged electrons, and uncharged neutrons
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protons
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have + charge and mass of 1 amu
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neutrons
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have - charge and mass of 1 amu
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electrons
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found moving around the nucleus have negative chare and 0 amu
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Atoms are electrically _______?
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neutral, and the number of electrons is equal to the number of protons (only thing they vary in is the number of neutrons
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isotope
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atoms with same # of protons but a dif. # of neutrons
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Atomic number
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equals number of protons
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# of protons
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equals number of electrons
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mass number
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equals # of protons + # of neutrons
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molecule
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a combination of 2 or more atoms
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chemical bond
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an energy relationship between the electrons of the reacting atoms
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chemically reactive elements
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do not have their outermost energy level fully occupied by electrons
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valence shell
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shell farthest from the nucleus (electrons hear are most energetic
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bonds
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made using electrons in the outermost shell
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electron shells
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each electron shell has a different energy level
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octet rule
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exept for 1st shell wh/ is full w/ 2 electrons, atoms interact in a manner to have 8 electrons in their valence shell
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Types of Chemical Bonds
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ionic, covalent, hydrogen
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ionic bonds
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between 2 atoms that transfer one or more elsectrons from one atom to the other.
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covalent bonds
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Covalent bonds are formed when atoms share electron pairs. If the electron pairs are shared equally, the molecule is nonpolar (O=C=O). Unequal sharing it is plor ( a dipole H-O-H) Single sharing shares 1, double covalent and triple share 2 and 3.
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hydrogen bonds
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weaker bonds formed between hydrogen and nitrogen or hydrogen and oxygen (intramolecular bonds). They bind together different molecules (e.g., water molecules) or different parts of the same molecule (as in protein molecules). Important in giving the molecule a 3d shape (e.g., DNA) They form and break down easily.
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Chemical Reactions
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occur whenever bonds are formed, rearranged, or broken.
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Chemical Equations
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describes what happens in a reation.
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Patterns of Chemical Reaction
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Synthesis, decomposition, and exchange reactions
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synthesis reaction
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combination (A+B > AB)
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Decomposition reactions
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Molecules are broken down. (AB > A + B)
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Exchange Reactions
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Bonds are both made and broken (AB + C > AC + B)
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Oxidation - reduction reaction
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may be considered a special type of exhange reaction. Reactants losing electrons are electron donars and are oxidized. Reactants taking up electrons are electron acceptors and are reduced. Na +Cl > NaCl
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Energy flow in chem reactions
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exergonic: reactions that release energy (lose heat). Endergonic: reactions that absorb energy (gain heat)
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Reversibility of Chem Reactions
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All chemical reactions are theoretically reversible.
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Factors Influencing the rate of Chemical Reactions
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Collision: particles are encountering each other and valence shells interact. Temperature: proceed quicker at higher temps. Particle size: smaller the particle the faster the chem reaction. Concentration of reactants - higher reacting particale concentrations produce faster reactions. Catalysts: increase the rate of reaction w/o being chemically changed. Enzymes: proteins that increase teh rate of reaction.
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Inorganic Compounds
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do not contain carbons
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Water
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Most important inorganic molecule, makes up to 60-80% of the volume of most living cells. High heat capacity: absorbs & releases large amounts of heat before changing temp. High Heat of Vaporization: changing from liquid to a gas requires large amounts of heat. Universal Solvent: Polar Solvent properties, disolves ionic substances, forms hydration layer around large charged molecules. Cushions around organs of the body.
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Salt
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Inorganic compound. Salts are ionic compounds containing cations other than H+ and anions other than Hydroxl (-OH) ion. When salts are dissolved in water they dissociate into their component ions. Conduct electrical currents.
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Acids and Bases
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Acids release H+ and are therefore proton donars HCI > H+ + Cl. Bases release OH- and are proton acceptors. NaOH > Na+ + OH.
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pH units
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Acid base concentration. Acidic solutions have a higher H+ concentration and therefore a lower pH. Alkaline solutions have a lower H+ concentration and therefore a higher pH. Neutral solustions have = H+ and OH- concentrations.
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pH reflects
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the # of FREE (not bound) H+ ions.
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pH scale
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scale 0-14. 7 is neutral. pH below 7 is acidic. pH above 7 is basic or alkaline.
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Buffers
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systems that resist changes in the pH of body fluids (e.g., cabonic acid/bicarbonate ion system)
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organic compounds
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contain carbons:Those found in the body include carobydrates, lipids, proteins, and nucleic acids.
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Carbohydrates
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contain carbon, hydrogen, and oxygen. Major function is supply a source of cellular food (broken down to make energy). Group of molecules containing sugars and starches. Monosaccharides: simple sugars. Disaccharides: linked monosaccharide units.
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Lipids
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Contain C, H, and O (less O than carbs). Lipids are insoluble in water but dissolve readily in nonpolar solvents (fats or organic solvents).
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phospholipids
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modified triglycerides w/ 2 fatty acid groups and a phosphorous group wh/ makes them ampipathic (hate & like water) are critical in the cell membrane. Found in all plasma membrane.
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Steroids
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flat molecule w/ 4 interlocking hydrocarbon rings
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Eicosanoids
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20 carbon fatty acids found in cell membranes, prostate glands
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Proteins
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macomolecules composed of combination of 20 types of amino acids bound together w/ peptide bonds.
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Proteins compose ____% of cell mass
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10-30%
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Protein function
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basic structural material of the body. Play vital roles in cell function.
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4 structural levels of proteins
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primary, secondary, tertiary, quaternary - 2 strands come together to form a particular protein (e.g., hemoglobin)
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Fibrous and Globular Proteins
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Structure denotes function!!
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fibrous proteins
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"structural proteins" extended & strandlike proteins, e.g., keratin, elastin, collagen, and certain contractile fibers. Fiibrous proteins are stable.
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Globular proteins
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"functional proteins" compact, spherical proteins w/ tertiary & quaternary structures. E.g., anitbodies, hormones, and enzymes. Globular proteins are susceptible to denaturing.
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Protein denaturation
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a loss of the specific 3-D structure due to chemical and physical changes usually occurs in globular, but not fibrous, proteins. Unfolding of proteins due to drops in pH and/or increased temp. Irreversibly denatured proteins cannot refold and the active site of the protein is destroyed., e.g. the boiled egg.
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Molecular chaperones
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are a type of globular protein that hlp proteins achive their 3-D shape.
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Enzymes
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globular proteins that act as biological catalysts. Each one is chemically specific and name ends in "ase". They work by lowering the activation energy of a reaction.
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Nucleic acids
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composed of C, O, H, N, and phosphorus are the largest molecules of the body.
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Nucleotides
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the structural units of nucleic acids
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3 components of nucleotides
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pentose sugar, phosphate group, and nitrogen-containing base
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5 nitrogenous bases used in nucleic acids
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Adenine (A), Guanine (G), Cytosine ©, Uracil (U), & Thymine (T). C,T, U are pyrimindines. A & G are purines. T is only in DNA. U is only in RNA
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DNA
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double stranded helical molecule found in the nucleus of a cell wh/ provides instructions for protein synthesis. Genetic material of the cell. DNA replicates itself before cell division ensuring genetic community. A, G, C, & T. A bonds to T, G bonds to C.
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Complementary bases
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the bases that always bind together
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RNA
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single stranded polymer containing the nitrogenous bases A, G, C, and U, and the sugar ribose. In RNA, G bonds w/ C, and A bonds w/ U.
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ATP or Adenosine Triphosphate
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source of immediatley usable energy for the cell. Adenine- containing RNA nucleotide w/ 2 additional phospate groups (totally 3). The additional phosphate groups are connected by high energy bonds. Breaking the high energy bonds releases energy the cell can use to do work. ATP is the energy currency used by the cell. ATP drives cellular work by transport work, mechanical work and chemical work.
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triglycerides
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neutral fats . Composed of fatty acids & glycerol. 3:1 fatty acid to glycerol therefore the name.
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what determines how solid a nuetral fat is at a given temperature
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the length of a neutral fat's fatty acid chains and their degree of saturation w/ H atoms.
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saturated fats
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fatty acid chain w/ only single covalent bond between carbon atoms
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saturated
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are solid at room temp and common in animal fats
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