Unit 1 Important Vocab Flashcards
sharing a pair of valence electrons by two atoms
Covalent bond
differences in atomic electronegativities
polarity
2 of the same molecules forming hydrogen bonds
cohesion
2 different molecules form hydrogen bonds
adhesion
anything that takes up space and has mass; also made up of elements
matter
a substance that cannot be broken down to other substances by chemical reactions
element
a substance consisting of two or more elements in a fixed ratio; has emergent properties - characteristics different from those of its elements
compound
needed by an organism to live
a healthy life and reproduce
essential elements
only required in minute quantities
Trace elements
smallest unit of matter that still
retains the properties of an element
atom
3 main subatomic particles
protons, neutrons, electrons
what forms atomic nucleus
protons and neutrons
what “floats” or is a ring around the atomic nucleus
electrons
what is neutron mass and proton mass measured in
daltons
number of protons in its nucleus
atomic number
sum of protons plus neutrons in the nucleus
mass number
Atomic mass
can be approximated by the mass number
two atomic forms of an element that differ in number of neutrons
Isotopes
capacity to cause change
energy
energy that matter has because of its location or structure
potential energy
outermost shell
valence shell
Two or more atoms held together by covalent bonds
molecule
H–H
structural formula
H_2
molecular formula
an atom’s attraction for the electrons of a covalent bond
electronegativity
atoms share the electrons equally
nonpolar covalent bond
one atom is more electronegative, and the atoms do not share the electron equally
polar covalent bond
Both atoms have complete valence shells, transfer of an electron, both atoms have charges
ions
positively charged ion
cation
negatively charged ion
anion
an attraction between an anion and a cation
ionic bond
weak chemical bonds
ionic bonds, hydrogen bonds, van der waals interactions
hydrogen atom covalently bonded to one electronegative atom is also attracted to another electronegative atom
hydrogen bond
regions of positive or negative charge enable all atoms and molecules to stick to one another
van der waals interactions
making and breaking of chemical bonds
chemical reactions
starting molecules of a chemical reaction are called
reactants
final molecules of a chemical reaction are called
products
the forward and reverse reaction rates are equal
chemical equilibrium
water molecules staying close together
cohesion
clinging of one substance to another
adhesion
measure of how hard it is to break the surface of a liquid
surface tension
energy of motion
kinetic energy
measure of the total amount of kinetic energy due to molecular motion
thermal energy
represents the average kinetic energy of molecules
temperature
Thermal energy in transfer from one body of matter to another
heat
the amount of heat required to raise the temperature of 1 g of water by 1°C
calorie
the amount of heat that must be absorbed or lost for 1 g of that substance to change its temperature by 1°C
specific heat
Heat is absorbed when hydrogen bonds break,
Heat is released when hydrogen bonds form
water’s high specific heat
liquid that is a homogeneous mixture of substances
solution
dissolving agent of a solution
solvent
substance that is dissolved
solute
water is the solvent
aqueous solution
an affinity for water
hydrophilic
no affinity for water
hydrophobic
sum of all masses of all atoms in a molecule
Molecular mass
number of moles of solute per liter of solution
Molarity
increase the H+ concentration in water
acids
reduce concentration of H+ in water
bases
substances that minimize changes in concentrations of H+ and OH-
buffers
human buffer
carbonic acid
a compound containing carbon
organic compound
3 macromolecules
carbohydrates, proteins, lipids
organic molecules consisting of only carbon and hydrogen
Hydrocarbons
compounds that have the same number of atoms of the same elements but different structures and properties
isomer
differ in the covalent arrangement of their atoms
structural isomers
carbons have covalent bonds to the same atoms, but the atoms differ in their spatial arrangement due to inflexibility of double bonds
cis-trans isomers
isomers that are mirror images of one another and differ in shape due to the presence of an asymmetric carbon
Enantiomers
the chemical groups that affect molecular function by being directly involved in chemical reactions
Functional groups
seven functional groups that are most important in the chemistry of life
Hydroxyl group, Carbonyl group, Carboxyl group, Amino group, Sulfhydryl group, Phosphate group, Methyl group
alcohol
hydroxyl group
ketone, aldehyde
carbonyl group
carboxylic acid, or organic acid
carboxyl group
amine
amino group
thiol
sulfhydryl group
organic phosphate
phosphate group
methylated compound
methyl group
organic molecule called adenosine attached to a string of three phosphate groups
adenosine triphosphate (ATP)
a long molecule consisting of many similar building blocks
polymer
small building-block molecules
monomer
two monomers bond together through the loss of a water molecule
dehydration reaction
Polymers disassembled to monomers, two monomers break through the gaining of a water molecule
hydrolysis
speed up chemical reactions
enzymes
include sugars and the polymers of sugars
carbohydrates
simplest carbohydrate
monosaccharides (simple sugars)
most common monosaccharide
glucose
dehydration reaction joins two monosaccharides
disaccharide (glycosidic linkage)
polymers of sugars, have storage and structural roles
polysaccharides
a storage polysaccharide of plants, consists entirely of glucose monomers
starch
storage polysaccharide in animals
glycogen
major component of the tough wall of plant cells
cellulose
found in the exoskeleton of arthropods, also provides structural support for the cell walls of many fungi
chitin
do not form true polymers
lipids
unifying feature of lipids
having little or no affinity for water
why lipids are hydrophobic
they consist mostly of hydrocarbons, which form nonpolar covalent bonds
most biologically important lipids
fats, phospholipids, steroids
glycerol and fatty acids make what
fats
three-carbon alcohol with a hydroxyl group attached to each carbon
glycerol
a carboxyl group attached to a long carbon skeleton
fatty acid
have the maximum number of hydrogen atoms possible and no double bonds
saturated fatty acids
have one or more double bonds
unsaturated fatty acids
major function of fats
energy storage
two fatty acids and a phosphate group are attached to glycerol
phospholipids
lipids characterized by a carbon skeleton consisting of four fused rings
steroids
a component in animal cell membranes
cholesterol
defense, storage, transport, cellular communication, movement, and structural support
protein functions
act as catalysts, to speed up chemical reactions without being consumed in the reaction
enzymatic proteins
unbranched polymers built from the same set of 20 amino acids
polypeptides
biologically functional molecule that consists of one or more polypeptides
protein
organic molecules with carboxyl and amino groups
amino acids
side chains
R groups
unique sequence of amino acids
primary structure
consists of coils and folds in the polypeptide chain
secondary structure
determined by interactions among various side chains
tertiary structure
results from interactions between multiple polypeptide chains
quaternary structure
loss of a protein’s native structure
denaturation - biologically inactive
a nucleic acid made of monomers called nucleotides
DNA (gene)
two types of nucleic acids
deoxyribonucleic acid (DNA), Ribonucleic acid (RNA)
consists of a nitrogenous base, a pentose sugar, and one or more phosphate groups
nucleotide
portion of a nucleotide without the phosphate group
nucleoside
only found in DNA
Thymine
only found in RNA
Uracil
sugar in DNA
deoxyribose
sugar in RNA
ribose
pairs of nitrogenous bases in DNA
A-T G-C (complementary base pairing)
pairs of nitrogenous bases in DNA
A-U G-C
the approach used to analyze large sets of genes or compare the genomes of different species
genomics
analysis of proteins
proteomics
