A&P 2: Chemistry Comes Alive Flashcards
(141 cards)
1
Q
Matter
A
anything that occupies space and has mass
2
Q
Energy
A
capacity to do work, or to put matter in motion
3
Q
Kinetic energy
A
energy in action
4
Q
Potential energy
A
stored energy; inactive energy that has the capability to do work but is not presently doing so
5
Q
Chemical energy
A
form of energy stored in the bonds of chemical substances
6
Q
Electrical energy
A
results from the movement of charged particles
7
Q
Mechanical energy
A
energy directly involved in moving matter
8
Q
Radiant energy (electromagnetic energy)
A
energy that travels in waves
9
Q
Elements
A
all matter is composed of these unique substances that cannot be broken down into simpler substances by ordinary chemical methods
10
Q
Periodic table
A
provides a more complete listing of the known elements and helps to explain the properties of each element that makes it react as it does with other elements
11
Q
Atoms
A
each element is composed of more or less identical particles (building blocks)
12
Q
Physical properties
A
those we can detect with our senses, e.g. color, texture
13
Q
Chemical properties
A
pertain to the way atoms interact with other atoms (bonding behavior) and account for the facts that iron rusts, animals can digest their food, etc.
14
Q
Atomic symbol
A
each element is designated by a 1 or 2 letter chemical shorthand, usually the 1st letter of the element’s name
15
Q
Nucleus
A
atom has a central one of these containing protons and neutrons tightly bound together
16
Q
Protons
A
bear a positive charge
17
Q
Neutrons
A
neutral part of the nucleus
18
Q
atomic mass unit (amu)
A
protons and neutrons are heavy particles and have approximately the same mass, 1 of these
19
Q
Electrons
A
bear a negative charge equal in strength to the positive charge of the proton
20
Q
Planetary model
A
simplified, outdated model of atomic structure
21
Q
Orbitals
A
regions around the nucleus in which a given electron or electron pair is likely to be found most of the time
22
Q
Orbital model
A
modern model of atomic structure; depicts probable regions of greatest electron density by denser shading (electron cloud)
23
Q
Atomic number
A
equal to the number of protons in its nucleus and is written as a subscript to the left of its atomic symbol
24
Q
Mass number
A
sum of the masses of its protons and neutrons
25
Isotopes
nearly all known elements have two or more of these structural variations, which have the same number of protons (and electrons) but differ in the number of neutrons
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Atomic weight
average of the relative weights (mass numbers) of all the isotopes of an element, taking into account their relative abundance in nature; approximately equal to the mass number of its most abundant isotope
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Radioisotopes
isotopes that exhibit radioactivity
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Molecule
combination of 2 or more atoms held together by chemical bonds
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Compound
when 2 or more different kinds of atoms bind
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Mixtures
substances composed of 2 or more components physically intermixed
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Solutions
homogeneous mixtures of components that may be gases, liquids, or solids
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Solvent
substance present in the greatest amount in a solution; usually liquids
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Solutes
substances present in smaller amounts in a solution
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Percent
parts per 100 parts
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Molarity (M)
moles per liter
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Mole
a ____ of any element or compound is equal to its atomic weight or sum of the atomic weights
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Molecular weight
sum of atomic weights in grams
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Avogadro's number
6.02 x 10^23; number of particles in one mole of a substance
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Colloids
emulsions; heterogeneous mixtures; composition is dissimilar in different areas of the mixture; often appear translucent/milky; scatter light but do not settle
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Sol-gel transformations
ability to change reversibly from a fluid state to a more solid state
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Suspensions
heterogeneous mixtures with large, often visible solutes that tend to settle out
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Chemical bonds
when atoms combine with other atoms, they are held together by these
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Electron shells
electrons forming the electron cloud around the nucleus of an atom occupy these regions of space that consecutively surround the atomic nucleus
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Energy level
each electron shell represents a different one of these
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Valence shell
indicates an atom's outermost energy level or that portion of it containing the electrons that are chemically reactive
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Octet rule (rule of 8's)
except for shell 1 which is full when it has 2 electrons, atoms tend to interact in such a way that they have 8 electrons in their valence shell
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Ions
charged particles that form due to the transfer of electrons
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Ionic bond
chemical bond between atoms formed by the transfer of 1 or more electrons from 1 atom to another
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Anion
gains 1 or more electrons; electron acceptor; acquires a net negative charge
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Cation
atom that loses electrons; electron donor; acquires a net positive charge
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Crystals
large arrays of cations and anions held together by ionic bonds
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Covalent bonds
electron sharing produces molecules in which the shared electrons occupy a single orbital common to both atoms, which constitutes this type of bond
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Nonpolar molecules
equal sharing of electrons (do not have separate + and - poles of charge)
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Polar molecule
unequal electron pair sharing, especially in non-symmetrical molecules containing atoms with different electron-attracting abilities
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Electronegativity
electron-hungry; capability to attract electrons very strongly
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Electropositive
electron-attracting ability is so low that an atom usually loses its valence shell electrons to other atoms; potassium and sodium are good examples
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Dipole
a polar molecule; one with two poles of opposite charge where the charges are not cancelled out
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Reactants
substances that react together to form products
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Products
the end result of reactants coming together or breaking apart
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Molecular formula
element symbols and numbers that represents a molecule
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Synthesis
combination reaction that always involves bond formation; when atoms or molecules combine to form a larger, more complex molecule
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Anabolic
pertaining to the construction or building up of compounds/molecules
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Decomposition reaction
occurs when a molecule is broken down into smaller molecules or its constituent atoms
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Catabolic
degradative reaction; pertaining to the breaking down of compounds/molecules
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Exchange/displacement reactions
involve both synthesis and decomposition; bonds are both made and broken
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Oxidation-reduction reactions (redox reactions)
decomposition reactions; basis of all reactions in which food fuels are broken down for energy (ATP is produced)
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Oxidized
reactant losing electrons is referred to as the electron donor and is said to be this
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Reduced
reactant taking up the transferred electrons is called the electron acceptor and is said to become this
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Exergonic reactions
reactions that release energy; reactions yield products with less energy than the initial reactants
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Endergonic reactions
energy-absorbing reactions; products contain more potential energy in their chemical bonds than did the reactants
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Chemical equilibrium
neither the forward nor the reverse reaction is dominant; for each molecule of product formed, one product molecule breaks down, releasing the reactants
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Catalysts
substances that increase the rate of chemical reactions without themselves becoming chemically changed or part of the product; if biological = enzymes
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Biochemistry
study of the chemical composition and reactions of living matter
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Organic compounds
compounds containing carbon; all are covalently bonded, many are large
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Inorganic compounds
all other chemicals in the body, including water, salts, and many acids and bases
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Universal solvent
water b/c unparalleled solvent
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Hydration layers
water forms layers of its molecules around large charged molecules such as proteins, shielding them from the effects of other charged substances in the vicinity and preventing them from settling out of solution
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Hydrolysis reactions
decomposition reactions made by adding a water molecule to each bond to be broken; "water splitting"
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Dehydration synthesis
when large carbohydrate or protein molecules are synthesized from smaller molecules, a water molecule is removed for every bond formed
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Electrolytes
ions; substances that conduct an electrical current in solution
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Acids
substance that releases hydrogen ions (H+) in detectable amounts; proton donor; sour taste
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Bases
bitter taste, slippery feel; proton acceptors; take up hydrogen ions in detectable amounts
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Hydroxyl ions
OH-; hydroxides dissociate in water and liberate OH- and cations
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Bicarbonate
HCO3-; important base in the body; particularly abundant in blood
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Ammonia
NH3; common waste product of protein breakdown in the body; a base with 1 pair of unshared electrons that strongly attracts protons
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pH units
relative concentration of hydrogen ions in various body fluids is measured in these
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Neutralization reaction
joining an acid and a base to form water, which neutralizes a solution
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Buffers
resist abrupt and large swings in the pH of body fluids by releasing hydrogen ions (acting as acids) when the pH begins to rise and by binding hydrogen ions (acting as bases) when the pH drops
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Strong acids
acids that dissolve completely and irreversibly in water; can dramatically change the pH of a solution
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Weak acids
acids that do not dissociate completely; ex. carbonic acid (H2CO3), acetic acid (HAc)
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Strong bases
those, like hydroxides, that dissociate easily in water and quickly tie up H+
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Weak base
a base, like sodium bicarbonate, that ionizes incompletely and reversibly; accepts relatively few protons
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Carbonic acid-bicarbonate system
major blood buffer; dissociates reversibly, releasing bicarbonate ions and protons
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Electroneutral
never losing or gaining electrons, like carbon; always shares electrons
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Polymers
chainlike molecules made of similar or repeating units (monomers), which are joined together by dehydration synthesis
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Monomers
base unit of a polymer
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Carbohydrates
group of molecules that includes sugars and starches; represents 1-2% of cell mass; contain carbon, hydrogen, and oxygen in a 2:1 ratio; classified according to size and solubility
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Monosaccharides
simple sugars; single-chain or single-ring structures containing 3-7 carbon atoms; carbon, hydrogen, and oxygen in a 1:2:1 ratio; named according to number of carbons they contain
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Isomers
having the same molecular formula but with differently arranged atoms, thus giving them different chemical properties
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Disaccharide
double sugar; formed when 2 monosaccharides joined by dehydration synthesis; sucrose (glucose + fructose), lactose (glucose + galactose), maltose (glucose + glucose); too large to pass through cell membranes so must be broken down to simple sugars to be absorbed into the blood
101
Polysaccharides
polymers of simple sugars linked together by dehydration synthesis; large, fairly insoluble molecules so ideal storage products; lack the sweetness of simple/double sugars; ex. starch, glycogen
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Lipids
insoluble in water but dissolve readily in others of its kind and in organic solvents such as alcohol and ether
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Triglycerides
neutral fats; commonly known as fats when solids or oils when liquid; composed of 3 fatty acids and glycerol
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Fatty acids
linear chains of carbon and hydrogen atoms (hydrocarbon chains) with an organic acid group (-COOH) at one end
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Glycerol
modified simple sugar (a sugar alcohol)
106
Saturated
fatty acid chains with only single covalent bonds between carbon atoms; chain is straight; at room temperature = solid
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Unsaturated
fatty acids that contain 1+ double bonds between carbon atoms; can be monounsaturated or polyunsaturated; chain is kinked so they can't be packed closely enough to solidify; liquid at room temperature, typical of plant lipids; ex. olive oil, peanut oil, corn/soybean/safflower oils
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Trans fats
common in many margarines and baked products; oils that have been solidified by addition of H atoms at sites of carbon double bonds; increase the risk of heart disease more so than the solid animal fats
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Omega-3 fatty acids
found naturally in cold-water fish; appear to decrease the risk of heart disease and some inflammatory diseases
110
Phospholipids
modified triglycerides, specifically diglycerides with a phosphorus-containing group and two fatty acid chains; tail is nonpolar, phosphorus head is polar; chief material for building cellular membranes
111
Steroids
flat molecules made of 4 interlocking hydrocarbon rings; fat soluble, contain little oxygen; most important = cholesterol, which is essential for life (cell membranes, raw material for synthesis of vitamin D, steroid hormones, and bile salts); vital to homeostasis
112
Eicosanoids
diverse lipids chiefly derived from a 20-carbon fatty acid (arachidonic acid) found in all cell membranes; most important of these are the prostaglandins and their relatives, which play roles in various body processes, including blood clotting, regulation of blood pressure, inflammation, and labor contractions; synthesis and inflammatory actions are blocked by NSAIDs and COX-2 inhibitors
113
Protein
10-30% of cell mass; basic structural material of the body; not all are construction materials; vital role in cell function; include enzymes, hemoglobin, contractile ___ in muscle; varied functions; all contain carbon, oxygen, hydrogen, and nitrogen; many contain sulfur
114
Amino acids
building blocks of proteins; 20 common types; 2 important functional groups - (1) an amine group (-NH2) and an organic acid group (-COOH); may act as either a base (proton acceptor) or acid (proton donor); all are identical except for a single group of atoms called their R group
115
Peptide bond
characteristic arrangement of linked atoms in proteins; can be di-, tri-, or poly- (10+)
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Macromolecules
most proteins are these large, complex molecules containing from 100 to over 10,000 amino acids
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Alpha helix
most common type of secondary structure of a protein (coiled); stabilized by hydrogen bonds formed between NH and CO groups in amino acids in the primary chain (4 amino acids apart); hydrogen bonds in these always link different parts of the same chain together
118
Beta-pleated sheet
secondary structure of a protein; primary polypeptide chains do not coil, but are linked side by side by hydrogen bonds to form a pleated, ribbonlike structure that resembles an accordion; hydrogen bonds may link together different polypeptide chains as well as different parts of the same chain that has folded back on itself
119
Fibrous proteins
extended, strandlike; some exhibit only secondary structure; most have tertiary or quaternary structure; ex. collagen; insoluble in water, very stable; ideal for providing mechanical support and tensile strength for the body's tissues; other examples = keratin, elastin, and certain contractile proteins of muscle
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Structural proteins
AKA fibrous proteins because they are the chief building materials of the body
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Globular proteins
compact, spherical proteins that have at least tertiary structure; some have quaternary structure; water-soluble, chemically active; play crucial roles in virtually all biological processes; AKA functional proteins; some help provide immunity (antibodies), some regulate growth & development (protein-based hormones), others are catalysts that oversee just about every chemical reaction in the body (enzymes)
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Denatured
protein's hydrogen bonds begin to break when the pH drops or the temperature rises above normal (physiological) levels, causing proteins to unfold and lose their specific 3D shape; usually reversible (when desired conditions are restored)
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Active sites
function of globular proteins depends on the presence of specific arrangements of atoms on their surfaces; regions that fit and interact chemically with other molecules of complementary shape/charge
124
Molecular chaperones
all cells contain this class of unrelated globular proteins which help proteins achieve their functional 3D structure; aid in folding process of proteins, helps translocate proteins and certain metal ions (Cu, Fe, Zn) across cell membranes, promotes breakdown of denatured proteins, interacts with immune cells to trigger the immune response to diseased cells
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Enzymes
globular proteins that act as biological catalysts
126
Holoenzyme
collective name for the 2 parts of a functional enzyme, consists of an apoenzyme and a cofactor
127
Apoenzyme
protein portion of an enzyme
128
Cofactor
may be an ion of a metal element (Cu/Fe) or an organic molecule needed to assist the reaction in some particular way
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Coenzyme
organic cofactor derived from vitamins, esp B Complex
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Substrate
substance on which an enzyme acts
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Activation energy
every chemical reaction requires that a certain amount of energy be absorbed to prime the reaction; amount of energy needed to break the bonds of the reactants so they can rearrange themselves and become the product
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Nucleic acids
composed of carbon, oxygen, hydrogen, nitrogen, and phosphorus; largest molecules in the body; 2 major classes - DNA & RNA
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DNA
deoxyribonucleic acid
134
RNA
ribonucleic acid; 3 types - messenger, ribosomal, & transfer; small molecules are called micro-_____ & appear to control genetic expression by shutting down genes or altering their expression
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Nucleotides
structural units of nucleic acids; quite complex; 3 components - nitrogenous base, pentose sugar, phosphate group
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5 Nitrogenous Bases
adenine, guanine, cytosine, thymine, uracil
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Adenine & Guanine
large, 2-ring bases (purines)
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Cytosine, Thymine, Uracil
smaller, single-ring bases (pyrimidines)
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Double helix
spiral staircase-like structure of DNA
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Complementary bases
adenine/thymine, guanine/cytosine
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ATP
adenosine triphosphate; primary energy-transferring molecules in cells, provides a form of energy that is immediately usable by all body cells; RNA nucleotide in which 2 additional phosphate groups have been added unstable energy-storing molecule b/c 3 negatively charged phosphate groups are closely packed and repel each other
