negatively charged. determine an atom's chemical behavior
atoms that have lost or gained electrons
portrays the atom as a miniature solar system, protons and neutrons are in the nucleus, electrons are in orbitals
more moders, predicts chemical behavior of atoms, electrons are depicted by an electron cloud, a haze of negative charge, outside the nucleus
equal to the number of protons that the atom contains. identifies the atom!
atomic mass number
sum of the protons and neutrons contained in an atom's nucleus
atoms of the same element with the same number of protons and same atomic number. vary in number of neutrons
close to mass number of most abundant isotope. reflects natural isotope variation
heavy isotope of certain atoms. tends to be unstable. decomposes to more stable isotope
process of spontaneous atomic decay
two or m ore atoms of the same elements combined chemically
two or more atoms of different elements combined chemically to form a molecule or a compound
occur when atoms combine with or dissociate from other atoms when chemical bonds are broken
rule of eights
atoms are considered stable when their outermost orbital has 8 electrons. the exception is shell 1, which can only hold 2 electrons
form when electrons are completely transferred from one atom to another. allows atoms to achieve stability through the transfer of electrons
negative charged due to gain of electrons
postive charge due to loss of electrons
atoms become stable through shared electrons. electrons are shared in pairs.
single covalent bonds
share one pair of electrons
double covalent bonds
share two pairs of electrons
polar covalent bonds
electrons are not shared equally between the atoms of the molecule. molecule has a positive and negative side, or pole.
hydrogen bonds- non covalent
weak chemical bonds. provides attraction between molecules. responsible for the surface tension of water. important for forming intramolecular bonds, as in protein structure. provides attraction between molecules
atoms or molecules combine. energy is absorbed for bond formation. underlies all anabolic activities in the body
molecule is broken down. chemical energy is released. underlies all catabolic activities in the body
involves both synthesis and decomposition reactions as bonds are both made and broken. switch is made between molecule parts, and different molecules are made
patterns of chemical reactions
most chemical reactions are reversible. reversibility is indicated by a double arrow.
lack carbon. tend to be small, simple molecules. include salts, water, and some acids and bases
contain carbon. all are large, covalently bonded molecules. include carbohydrates, lipids, proteins, and nucleic acids
contain cations and anions. easily dissociate into ions in the presence of water. vital to many body functions. all are electrolytes
ions that conducts electrical currents
release hydrogen ions when dissolved in water. strong acids ionize completely and liberate all their proteins. weak acids ionize incompletely
release hydroxyl ions when dissolved in water. are proton acceptors. strong bases seek hydrogen ions
type of exchange reaction in which acids and bases react to form water and a salt
measures relative concentration of hydrogen ions. based on the number of protons in a solution, expressed in terms of moles per liter
chainlike molecules made of many similar or repeating units (monomers)
monomers are joined to form polymers through the removal of water molecules
polymers are broken down into monomers through the addition of water molecules
simple sugars. contain 3-7 carbon atoms.
two simple sugars joined by dehydration synthesis
long branching chains of linked simple sugars. function as storage products
most abundant are triglycerides, phospholipids, and steroids. insoluble in water, but soluble in other lipids
neutral fats. found in fat deposits. source of stored energy. composed of three fatty acids and one glycerol molecule
contain only single covalent bonds, chains are straight, exists as solids at room temperature since molecules pack closely together
contain one or more double covalent bonds causing chains to kink, exists as liquid oils at room temperature, heart healthy
oils that have been solidified by the addition of hydrogen atoms at double bond sites
omega 3 fatty acids
found in cold water fish and plant sources, including flax, pumpkin, and chia seeds
contain two fatty acids rather than three, phosphorus containing head carries an electrical charge and is polar, form cell membranes
formed of 4 interlocking rings, liver makes cholesterol
account for over half of the body's organic matter, built from amino acids
contain fewer than 50 amino acids
appear in body structures, bind structures together and exist in body tissues, stable proteins, ex: collagen and keratin
function as antibodies, hormones, or enzymes. exhibit at least tertiary structure. can be denatured and no longer perform physiological roles. active sites fit and interact chemically with other molecules
biological catalysts, increase rate of chemical reactions
anything that has mass and takes up space is considered to be ____
(T/F) inactive or stored energy is called kinetic energy
what is the number of neutrons in an atom with the atomic mass of 35, three energy levels, and 7 valence electrons?
an atoms outermost shell is known as its ___ shell
which of the following contains sodium?
an atom has 6 protons, 8 neutrons, and 6 electrons. its atomic mass is ____
isotopes have different number of ____; thus they also have different _____
neutrons; atomic masses
which of these determines the chemical behavior of an atom?
electrons in the valence shell
which of these statements reflects the relationship between elements, atoms, and chemical symbols?
elements are composed of atoms
an atomic symbol is ____
a one or two letter abbreviation for an element
what does the molecular formula CO2 mean?
the molecule contains one atom of carbon and two atoms of oxygen
what is the best description of the term molecule?
two or more atoms combined chemically
a compound is defined as ____
a molecule composed of two or more elements
what type of bond is formed when electrons are transferred from one atom to another?
an ionic bond
polar molecules, like water, result when electrons are shared ____.
unequally between atoms
(T/F) the number of protons in an atom equals the atomic number for that element
(T/F) atoms that have lost or gained electrons during bonding are known as isotopes
(T/F) hydrogen bonds are very strong bonds that hold together water molecules
why are salts referred to as electrolytes?
after salts dissolve in a solution, the resulting ions can conduct an electrical current
which nitrogen containing base is found only in RNA?
an acid is a molecule that releases (donates) _____
protons (hydrogen ions)
glycogen and starch are examples of a specific category of carbohydrates called _____
enzymes are examples of ___ proteins
a nucleotide of DNA contain three components: ____,_____, and _____
deoxyribose; a phosphate group; nitrogen containing base
which carbohydrate is also known as blood sugar?
the building blocks of a triglyceride are ____
three fatty acid chains and one glycerol molecule
two or more polypeptides chains combine to form a complex structure called at _____
saturated fats ____
exist as solid at room temperature
the building blocks of proteins are ____
which of the properties of water is most closely associated with the body's ability to maintain a relatively constant internal temperature?
high heat capacity
(T/F) carbohydrates are classified as inorganic compounds
(T/F) water is the single most abundant inorganic compound in the human body
(T/F) the lower the pH, the greater the number of hydrogen ions released by a chemical into solution
(T/F) acids are defined as proton donors since they release hydrogen ions
(T/F) carbon is found in all inorganic compounds
(T/F) when a solution produces equal numbers of hydrogen and hydroxyl ions, it is said to be neutral
(T/F) amino acids are the building blocks for proteins
(T/F) glucose and fructose are classified as disaccharides
(T/F) phospholipids are composed of three fatty acid chains attached to one glycerol molecule
(T/F) disruption of the hydrogen bonds of functional proteins lead to their denaturation