Anatomy and Physiology Ch. 2

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Terms in this set (...)

matter
is anything that occupies space and has mass
kinetic energy
is the energy of motion
potential energy
is stored energy
elements
are unique substances that cannot be broken down into simpler substances by ordinary chemical means
atoms
are the smallest particles of an element that retain the characteristics of that element
protons
have a positive charge and weigh 1 atomic mass unit (amu)
neutrons
do not have a charge and weigh 1 amu
electrons
are found moving around the nucleus, have a negative charge, and are weightless
atomic number
is equal to the number of protons of an element
mass number
is equal to the number of protons plus the number of neutrons
isotopes
are structural variations of an atom that have the same number of protons, but differ in the number of neutrons
radioisotopes
are heavier, unstable isotopes of an element that spontaneously decompose into more stable forms
molecule
a combination of two or more atoms
mixtures
are substances made of two or more components mixed physically
solutions
are homogeneous mixtures of compounds that may be gases, liquids, or solids
solvent
the substance present in the greatest amount
solute
substances present in smaller amounts
colloids or emulsions
are heterogeneous mixtures that often appear milky, and have larger solute particles that do not settle out of solution
suspensions
are heterogeneous mixtures with large, often visible solutes that tend to settle out
octet rule (rule of eights)
states that except for the first energy shell (stable with two electrons), atoms are stable with eight electrons in their outermost (valence) shell
ionic bonds
are chemical bonds that form between two atoms that transfer one or more electrons from one atom to the other
anion
is an electron acceptor carrying a net negative charge due to the extra electron
cation
is an electron donor carrying a net positive charge due to the loss of an electron
crystals
are large structures of cations and anions held together by ionic bonds
covalent bonds
form when electrons are shared between two atoms
nonpolar molecules
share their electrons evenly between two atoms
polar molecules
electrons spend more time around one atom thus providing that atom with a partial negative charge, while the other atom takes on a partial positive charge
dipole
a polar molecule, due to the two poles of charges contained in the molecule
hydrogen bonds
are weak attractions that form between partially charged atoms found in polar molecules
surface tension
is due to hydrogen bonds between water molecules
synthesis (combination) reaction
larger molecules are formed from smaller molecules
decomposition reaction
a molecule is broken down into smaller molecules
exchange (displacement) reaction
involve both synthesis and decomposition reactions
oxidation-reduction reaction
are special exchange reactions in which electrons are exchanged between reactants
exergonic reactions
release energy as a product
endergonic reactions
absorb energy
catalysts (enzymes)
increase the rate of a chemical reaction without taking part in the reaction
high heat capacity
meaning that it absorbs and releases a great deal of heat before it changes temperature
high heat of vaporization
meaning that it takes a great deal of energy (heat) to break the bonds between molecules
acids
are also known as proton donors, and dissociate in water to yield hydrogen ions and anions
bases
are also called proton acceptors, and absorb hydrogen ions
organic compounds
carbohydrates, lipids, proteins, and nucleic acids
carbohydrates
are a group of molecules including sugars and starches and contain carbon, hydrogen, and oxygen
monosaccharides
are simple sugars that are single-chain or single-ring structures
disaccharides
are formed when two monosaccharides are joined by a dehydration synthesis
polysaccharides
are long chains of monosaccharides linked together by dehydration synthesis
lipids
are insoluble in water but dissolve readily in nonpolar solvents
triglycerides
(neutral fats) are commonly known as fats when solid and oils when liquid
phospholipids
are diglycerides with a phosphorus-containing group and two fatty acid chains
steroids
are flat molecules made up of four interlocking hydrocarbon rings
proteins
they are the basic structural material of the body and play vital roles in cell function
primary
the linear sequence of amino acids
secondary
proteins twist and turn on themselves to form a more complex structure
tertiary
resulting from a protein folding upon itself to form a ball-like structure
Quaternary
results from two or more polypeptide chains grouped together to form a complex protein
fibrous proteins
are extended and strandlike and are known as structural proteins and most have only secondary structure
globular proteins
are compact, spherical structures, they are water-soluble, chemically active molecules, and play an important role in vital body functions
denaturing
losing their shape due to breaking of their hydrogen bonds
protein denaturation
is a loss of the specific three-dimensional structure of a protein
molecular chaperones
are a type of globular protein that help proteins achieve their three-dimensional shape
nucleotides
are the structural units of nucleic acids
nucleic acids
composed of carbon, oxygen, hydrogen, nitrogen, and phosphorus are the largest molecules in the body
DNA
is the genetic material of the cell, and is found within the nucleus
RNA
is located outside the nucleus, and is used to make proteins using the instructions provided by the DNA
ATP
is the energy currency used by the cell