Chemistry 1110
the development of a chemical reaction
"for any reversible reaction in a closed system, whenever the opposing reactions are occurring at different rates, the faster reaction will gradually become slower, and the slower reaction will gradually become faster. finally, the reaction rates become equal, and equilibrium is established."
messenger RNA
"photocopy" of the protein plan
carboxyl group
-COOH
naming alkanes prefixes
1 carbon atom - meth 2 - eth 3 - prop 4 - but 5 - pent 6 - hex 7 - hept 8 - oct 9 - non 10 - dec
two things are needed when considering equilibrium calculations:
1. equilibrium equation 2. equilibrium constant expression (moles/liter)
how to predict the favored direction of an acid-base reaction
1. for a given pair of reactions, write the equation for the transfer of one proton from one species to another 2. label the acid and base on each side of the equation 3. determine which side of the equation has both the weaker acid and the weaker base, and that side identifies the products in the favored direction
naming alkanes
1. identify as the parent alkane the longest continuous chain, and name according to the prefix associated with the number of carbons 2. identify the number the carbon atom to which the alkyl group (or other species) is bonded to the chain 3. identify the branched group (or other species) 4. if the same alkyl group, or other species, appears more than once, indicate the number of appearances by di-, tri-, etc., and show the location of each branch by number 5. if two or more different alkyl groups, or other species, are attached to the parent chain, they are name din alphabetical order
oxidation # assignment rules
1. the oxidation number of each atom in any elemental substance is 0 2. the oxidation number of a monatomic ion is the same as the charge of the ion 3. the oxidation number of combined oxygen is -2, except in OF₂ it is +2 4. the oxidation number of a combined hydrogen is +1, except in a hydride ion it is -1 5. in any molecular or ionic species, the sum of the oxidation numbers of all atoms in a molecule or polyatomic ion is equal to the charge on the species
general bronsted-lowry theory equation
B + HA⁺ → HB⁺ + A⁻
the general formula of a cycloalkane is
C(n)H(2n)
naming alcohols
CH₄O alkyl group + alcohol: methyl alchol alkane prefix + -ol: methanol
central dogma of molecular biology
DNA replicates itself → transcription → RNA → translation →proteins
an acidic solution has a higher ____ concentration than _____ concentration.
H⁺ , OH₋
the equilibrium constant (K)
K = [C]^c ∙[D]^d / [A]^a ∙ [B]^b •when writing an equilibrium constant expression, use only the concentrations of gases (g) or dissolved substances (aq). do not include solids or liquids
the acid constant, Ka =
Ka = [H⁺][A⁻]/[HA] HA (aq) ↔ H⁺ (aq) + A⁻ (aq)
equilibrium constant for water
Kw = [H⁺][OH⁻] = 1.0 x 10⁻¹⁴ at 25° C there is an inverse relationship between [H⁺] and [OH⁻]: if one concentration goes up, the other goes down
reduction
a gain of elections or a reduction in oxidation number
oxidation
a loss of electrons or an increase in oxidation number
half reaction
a reaction that cannot occur by itself. oxidation-reduction reactions can be divided into an oxidation half-reaction equation and a reduction half-reaction equation. addition of these gives a balanced equation for a redox reaction
amphoteric
a substance that can behave as an acid in one case and a base in another
bronsted-lowry acids vs. bases
acids are compounds from which protons (H⁺) can be removed (proton donor), while bases are compounds that removes protons (proton acceptor)
naming esters
alcohol alkyl group + acid anion: methyl acetate alcohol alkyl group + acid alkane prefix + oate: methyl ethanoate C₃H₆O₂
alkyl group
an alkane from which one hydrogen has been removed, (-CH₃), where the dash indicates a bond that the alkyl is able to make with another atom
salt bridge
an apparatus that connects the two half cells in a voltaic cell so that the cell maintains electrical neutrality without bulk mixing of solutions
enzymes/substrate/active site/inhibitors
an enzymes substrate binds at the enzymes active site, and enzyme inhibitors compete with the substrate for the active site
hydroxyl group
an organic functional group, -OH, characteristic of alcohols
transition state
an unstable intermediate species formed during a collision of two reacting particles. the properties of a transition state cannot be described because the complex decomposes almost as soon as it forms.
naming ethers
both alkyl groups + ether: ethyl methyl ether alkyl group + -oxy- + alkane: methoxyethane C₃H₈O
carbohydrates
can be monosaccharides (simple sugars that cannot be converted to smaller carbohydrates), disaccharides (formed from two simple sugars), or polysaccharides (formed from many sugars) aldehydes or keytones with two or more -OH groups
chain-growth vs. step growth polymers
chain-growth: formed by repeated addition reaction of an alkene monomer to give an alkane-like polymer chain step-growth: formed by repeated condensation reactions to give a polymer chain with repeated ester or amide functional groups
conjugate acid-base pairs
combinations such as base B and acid HB⁺ as well as acid HA and base A⁻ that result from an acid losing a proton or a base B + HA⁺ → HB⁺ + A⁻ base B and acid HB⁺ are conjugate pairs acid ha and base A⁻ are conjugate pairs
naming amides
common acid prefix + -amide: formamide alkane prefix + -amide: methanamide CH₃NO
naming carboxylic acids
common name + acid: formic acid alkane prefix + -oic + acid: methanoic acid HCO₂H
naming aldehydes
common prefix + aldehyde: formaldehyde alkane prefix + -al: methanal CH₂O
isomers
compounds with the same molecular formula but different molecular structures
electrodes
conductors by whic electric charges enter or leave electrolytes
DNA
deoxyribonucleic acid (DNA): stores genetic information and transmits that information to the next generation during cell division
amides
derivatives of a carboxylic acid in which the hydroxyl part of the carboxyl group is replaced by an -NH₂ group R-CONH₂
example of monosaccharide
fructose
example of polysaccharide
glycogen
dipeptide
molecule composed of two amino acids
naming amines
name alkyl groups + amine: methylamine amino- + alkane: aminomethane CH₅N
naming ketones
name both alkyl groups + ketone: methyl ethyl ketone (number carbonyl carbon) + alkane prefix + -one: butanone; 2-pentanone C₄H₈O
nucleotides
nucleic acid monomers that are composed of a) an N-containing cyclic molecule called a base (image), b) a sugar, either ribose or deoxyribose, and c) one or more phosphate groups attached to the -OH groups of the sugar
amines
organic derivatives of ammonia, NH₃, that is formed by replacing one, two, or three hydrogens in an ammonia molecule with an alkyl group RNH₂ R₂NH R₃N
pH and pOH
pH = -log[H⁺] pOH = -log[OH⁻] [H⁺] = 10^(-pH) [OH⁻] = 10^(-pOH) pH + pOH = 14
macromolecules
polymeric molecules with molar masses starting from about 5000 g/mol and going up from there
transcription
process by which DNA creates a specific protein molecule
replication
process by which DNA duplicates itself during cell division
translation
process by which genetic information mRNA is decoded to produce a protein molecule
if K is very large (>1), there are mostly _________, and the the reaction will be favored towards the __________ direction. if K is very small (<1), there are mostly __________, and the reaction will be favored in the _______ direction . if K is close to 1, the reaction will be _______ .
products, forward reactants, reverse equal
gene
protein blueprint contained in DNA
substitution reaction
reaction in which a hydrogen atom in an alkane is replaced by an atom of another element
halogenation reaction
reaction with a halogen that both alkenes and alkanes undergo
RNA, tRNA, mRNA
ribonucleic acid (RNA): assists in the transmission of genetic information by transferring the correct amino acid during protein synthesis mRNA: carries instructions for protein synthesis from DNA to ribosomes tRNA: delivers specific individual amino acids to the ribosomes
saturated vs. unsaturated
saturated: each carbon is bonded to the maximum four other atoms and there is no room for the carbon atom to form another bond unsaturated: carbon is bonded to fewer than the maximum number of atom sit is capable of
α-helix structure
secondary structure that allows for the maximum hydrogen bonding and the greatest stability in a continuous series of loops stabilized by INTRAchain hydrogen bonds
β-pleated sheet
secondary structure that allows for the maximum hydrogen bonding and the greatest stability in a curtain with sharp angles, like pleats stabilized by INTERchain hydrogen bonds
strong vs. weak acid
strong acids are ones that ionize almost completely and lose their protons readily, while weak acids ionize but only slightly
strong vs. weak base
strong bases have a strong attraction for protons, while weak bases dissociate only slightly in aqueous solutions and have a weak attraction for protons
ribosome
structure outside of the nucleus where protein synthesis occurs
example of disaccharide
sucrose
methyl group
the one carbon alkyl structural group -CH₃
induced fit model
the shape of the substrate is a close, but not exact, match to the shape of the active site of the enzyme. as the substrate binds to the enzyme, either or both molecules change shape slightly.
naming alkenes and alkynes
they follow the same naming system as alkanes, but with respective suffices -ene and -yne
Arrhenius theory of acids and bases
•Arrhenius acid: substance that increases the concentration of H+ ions when dissolved in water •Arrhenius base: substance that increases the concentration of OH ions when dissolved in water •acids react with CO₃²⁻ to produce CO₂ •acids react with some metals to produce H₂ •bases react with some metal ions to produce solids
aldehydes
•R-CHO •easily oxidized •can be reduced to alcohols
ketone
•R-CO-R' •resist oxidation •can be reduced to alcohl
aromatic hydrocarbon
•a hydrocarbon with one or more benzene rings •an alkyl group, halogen, or other species may replace hydrogen on a benzene ring
benzene ring
•a planar, 6-carbon structural unit connected by delocalized reactions •benzene is nonpolar and liquid at room temperature
alkanes
•alkane: each carbon atom forms single bonds to four other atoms, and there are no multiple bonds •C(n)H(2n+2) •all alkanes are nonpolar •cycloalkanes: have all carbon-carbon single bonds with at least some of the carbon atoms forming a ring •alkanes with fewer than 5 carbons have weak intermolecular forces, low boiling points, are gases at room temperature, and are all used as fuels •alkanes with grater than 5 carbons are liquid at room temperature and make up diesel fuel and lubricating oils
bronsted-lowry theory of acids and bases
•an acid-base reaction is a proton transfer reaction in which the proton is transferred from the acid to the base •acids are compounds from which protons can be removed, and a bases are compounds that can remove protons from an acid •anything that can take away a proton is a base
hydrocarbon
•binary compounds of carbon and hydrogen
classical properties of bases
•bitter taste •neutralize acids •form precipitates when added to solutions of most metal ions •liquid solutions of bases feel slipper or soapy
alcohols
•consist of an alkyl group and hydroxyl group, R-OH •the suffix -ol denotes an alcohol
esters
•esterification: reaction between an acid and an alcohol, the products of which are an ester and water •R-CO-OR'
ethers
•ether: removal of both hydrogen molecules from a water molecule and is completed when to alkyl groups bond to the oxygen •R-O-R' •prepared by dehydrating alcohol •relatively unreactive, highly flammable, and have low boiling points
alkenes
•hydrocarbons with at least one double bond •unsaturated
alkynes
•hydrocarbons with at least one triple bond •unsaturated
le chatelier's princples
•if an equilibrium system is subject to change, processes occur that tend to partially counteract the initial change, thereby brining the system to a new position of equilibrium •three effects: the concentration effect, the volume effect, and the temperature effect
le chatelier's principle: the temperature effect
•if heat is removed, the equilibrium will shift in the direction that produces heat •if heat is added, the equilibrium must shift in the other direction to "use up" the heat
le chatelier's principle: the volume effect
•if the volume is reduced, pressure increases, and therefore the equilibrium will shift to side with fewer molecules •if the volume is increased, pressure decreases, so the reaction will shift towards the side with more molecules to increase the pressure •only gaseous molecules are involved in pressure adjustments, so don't count s, l, or aq
the collision theory of chemical reactions
•if two molecules are to react chemically, they must come into contact with each other • what we see as a chemical reaction is the overall effect of a huge number of individual collisions between reacting particles •basically, for an individual collision to result in a reaction, the particles must have enough kinetic energy and the proper orientation to create a violent, bond-breaking collision •the rate of reaction depends on the frequency of effective collisions
amino acid
•molecule that contains both an amine (RNH2) group and a carboxylic acid (R-COOH) group •bond between amino acid is called a peptide linkage
4 structures of proteins
•primary structure: its sequence of amino acids •secondary: local spatial layout of the amino acid backbones •tertiary: describes the spatial arrangement of the entire polypeptide chain (3D) •quaternary: describes how its polypeptide chains are arranged to form a protein molecule (AKA how multiple polypeptide chains are arranged in relation to one another)
classical properties of acids
•sour, biting taste •react with carbonate ions and release carbon dioxide •react with and neutralize a base •release hydrogen when they react with particular metals
conditions that affect the rate of a chemical reaction
•temperature - reactions are faster at higher temperatures •the presence of a catalyst •concentration - the more particles there are i a given volume, the more frequently collisions will occur and the more rapidly the reaction will take place
the character of an equilibrium
•the equilibrium is closed in the sense that no substance can enter or leave the immediate vicinity of the system; all substances on one side of an equilibrium reaction must remain to form the substances on the other side •the equilibrium is dynamic; the reversible changes occur continuously at the particulate level in a state of dynamic equilibrium, even though there is no macroscopic appearance of change the things that are equal in an equilibrium are the forward rate of change and the reverse rate of change. •the amount of substances present in an equilibrium are not necessarily equal
reducing agent
•the species from which the electrons are removed •species that is itself oxidized
oxidizing agent
•the species that removes electrons •the species that is itself reduced
carboxylic acids
•weak acids that release a proton from the carboxyl group on ionization •R-COOH