the strongest of the three chemical bonds
Covalent bond
an uncharged particle in the atomic nucleus
neutron
a hydrogen ion
proton
the number of protons in the nucleus
atomic number
particles with a negative charge that move in shells around the nucleus
electrons
a bond formed by sharing electrons in the outermost shells
covalent bonds
a weak bond formed for example by the slight positive charge at the hydrogen end of the water molecule reaction with the negative end of other molecules
hydrogen bond
a bond formed by the gain or loss of electrons from the outer electron shell
ionic bond
the substance upon which an enzyme acts
substrate
a protein that lowers the activation energy required for a reaction
enzyme
the sum of the atomic weights of a molecule's atoms
molecular weight
the collective term for all decomposition reactions
catabolism
the number of grams equal to molecular weight
mole
the collective term for synthesis reactions
anabolism
the combining capacity of an atom
valence
an ion with a positive charge
cation
one of two molecules with the same chemical formula but different structures
isomer
prevents drastic changes in pH
buffer
substance that dissociates into ions that are neither OH- nor H+
salt
a proton donor
acid
dissociates into one or more negative hydroxide ions, such as OH-
base
combinations of atoms that have gained stability by completing the full complement of electrons in the outermost shell
molecule
Eight or more glucose molecules in a chain
disaccharide
sterol
compex lipid
fat
complex lipid
production of a molecule of water during synthesis
condensation
formed from chains of amino acids
proteins
lipoprotein
conjugated proteins
results from the release of energy by seperation of the terminal phosphate group
adenosine diphosphate
DNA
nucleic acid
triglycerides
simple lipids
same number of protons in the nucleus but different weights
isotope
a molecule containing at least two kinds of atoms such as water
compound
the D and L forms of an amino acid
stereoisomer
the substance formed by a reaction
product
sucrose
disaccharide
soluble in solvents such as ether or alcohol but not in water
lipids
purines or pyrimidines attached to a pentose sugar but without a phosphate group
nucleoside
have a hydrogen-to-oxygen ratio of 2:1, a general formula of CH20
carbohydrate
In DNA, it will pair with guanine
cytosine
In RNA it replaces thymine
uracil
the five-carbon sugar in dna
deoxyribose
bonds between amino acids in proteins
peptide
all atoms with the same atomic number are classified as the same____________
chemical element
when discussing synthesis, the combining substances are called_______and the subtance formed is the product.
reactants
carbon has a valence of
four
the principle energy-carrying molecule in all cells is _________
ATP
RNA differs from DNA in being usually ___________stranded.
single
In a protein, the order of the amino acid sequence is the ___________ level of organization.
primary
Thymine and cytosine are single-ring structures called________
pyrimidines
an example of a nitrogen-containg base in a nucleotide is___________
adenine, guanine cytosine thymine uracil
the ___________level of protein organizatino provides it with a three-dimensional shape.
tertiary
some important characteristics of water are its high _________and its's capacity as a temperature________.
boiling point; buffer
cations are positively charged ions; theri outer electron shell is ______than half filled and they lose electrons. (less, more)
less
the minimum collision energy required for a chemical reactions to occur is its___________
activation energy
neutrons and protons have a weight about 1840 times that of __________
electrons
decomposition yields energy, which is called an _________reaction
exergonic