Chapter 2 Flashcards
Atoms, Ions, and Molecules
matter is
a substance that has mass and takes up space
solids are
things that hold their shape without a container
liquids are
things that hold their shape with a container
gases are
things that have no shape, even with a container
matter is composed of
atoms
atoms are
the simplest whole particle
atoms create
elements
subatomic particles are found
within atoms
three main subatomic particles are
protons
electrons
neutrons
protons are _____ charged
positively
electrons are _____ charged
negatively
neutrons have a _____ charge
neutral
neutrons provide what to an atom?
mass
mass of an atom is expressed in
amu, atomic mass units
the periodic table organizes
elements
elements are organized on the periodic table by
mass, electronegativity, valence electron shell
electronegativity on the periodic table increases when
traveling up and right along the table
valence electrons are
the electrons on the outermost shell of the atom
the number of valence electrons an atom has is the same as
the atom’s group number
the octet rule applies to
valence electrons
which elements represent the octet rule?
group 8, noble gases
how many valence electrons does an atom want in its shell?
eight
six major elements of the body
oxygen
carbon
hydrogen
nitrogen
calcium
phosphorus
six minor elements of the body
sulfur
potassium
sodium
chlorine
magnesium
iron
isotopes are
atoms of the same elements with the same number of protons and electron, but different numbers of neutrons
radioisotopes are
isotopes that emit radioactive nuclei when they decay
the more neutrons an isotope has,
the more unstable it is and more radioactive
radioisotopes decay into
more stable versions of the isotope
physical half life is
the amount of time it takes 50% of the isotope to decay into its more stable isotope
biological half life is
the amount of time it takes half of the isotope to be eliminated from the body
half life calculation is important regarding
medication dosage and medical imaging
an ion is
an atom or group of atoms with an electric charge, either positive or negative
a cation is a
positively charged ion
an anion is a
negatively charged ion
five cations in the body
sodium
potassium
calcium
magnesium
hydrogen
three main anions in the body
chloride
bicarbonate
phosphate
how are ions formed? use NaCl as an example
When sodium and chloride meet to form sodium chloride (NaCl), table salt, sodium donates its single valence electron to chloride, which has seven. Chloride is more electronegative than sodium, which is why it attracts the electron more.
The addition of a negative charge to neutral elemental chloride gives it a -1 charge. The loss of a negative charge to neutral elemental sodium gives it a +1 charge.
polarity is
a trait of molecular bonds between atoms, based in electronegativity differences in these bonds
if a molecule is amphipathic
there are polar and nonpolar components in the same moelcule
if a molecule is polar
there is a large electronegativity difference between the bonds
if a molecule is nonpolar
there is small or no electronegativity difference between bonds
what is the polarity of water?
water is polar
the polar bonds in water produce
slightly positive and negative charges
the slight charges in water gives it the ability to
produce hydrogen bonds
each water molecule can create hydrogen bonds with _____ adjacent water molecules
four
four main roles of water in the body
transportation of molecules
lubrication to decrease friction
cushion
excretion of waste
solubility is
the degree to which a substance can be dissolved into another substance
solutes are
substances that are being dissolved
solvent is
the substance a solute is being dissolved in
a solution is
the creation of solute + solvent
general rule of solubility
like dissolves like
universal solvent is
water
hydrophobic exclusion is
a phenomena where the non polar molecules, when added to water, will tightly group together as far away from the water as possible
important amphipathic molecule in the body
phospholipids
ionic compounds _____ in water, producing ____
dissociate
ions
ions have the ability to
conduct electricty
primary ionic compound in the body
NaCl
electrolytes are
ions in the body that can conduct electricity
nonelectrolytes
are molecules that cannot conduct electricity
nonelectrolyte example
glucose
an acid is
a compound that dissociates in water to produce H+ and an anion
a base is
a compound that accepts an H+ when added to water
a proton acceptor is a
base
a proton donor is an
acid
most bases will contain
OH-, hydroxide ion
pH is how
acidic or basic a solution is
pH measures
H+ concentration
pH is also known as
potential of hydrogen
pH scale is from
0 to 14
a pH of 1 would be
very acidic
a pH of 13 would be
very basic
the difference between each number on the pH scale is how many times different?
10x
pH of blood
7.35 to 7.45, average 7.4
why is blood slightly basic?
bicarbonate ion presence
how does blood maintain such a tight pH range?
buffer systems, specifically the bicarbonate buffer system
neutralization is when
an acidic or basic solution is made neutral at a pH of 7
acidosis is
when blood pH is less than 7.35
alkalosis is when
blood pH is greater than 7.45
why aren’t buffers systems and neutralization the same?
buffer systems do not always result in a neutral pH, but work to maintain a specific pH range
bicarbonate buffer system chemical equation
CO2 + H2O <-> H2CO3 <-> HCO3- + H+
carbon dioxide + water -> carbonic acid -> bicarbonate ion + hydrogen ion
biological macromolecules are
large organic molecule synthesized by the body, always containing carbon, hydrogen, and oxygen
biological macromolecules may also contain
nitrogen, phopshorus, sulfur
hydrocarbons are
molecules that only contain hydrogen and carbon
hydrocarbon example
CH4, methane
hydrocarbons are always
nonpolar and hydrophobic
functional groups are
two or more atoms that always exhibit the same chemical characteristics when present on a molecule
functional group examples
-OH, hydroxyl
-COOH, carboxyl/carboxylic acid
-NH2, amine
- PO4 3-, phosphate
polymers are
molecules made up of repeating subunits called monomers
a dimer is
two monomers bound together
polymer examples
glycogen, proteins
dehydration synthesis
when two monomers join to form a dimer and water is lost in the process
hydrolysis
when a dimer is broken into two monomers and water is used to break the dimer
lipids are
a group of fatty, hydrophobic molecules
four main types of lipids in the body
triglycerides - energy storage
phospholipids - cell structure
steroids - precursor to hormones
eicosanoids - inflammation and immune response
carbohydrates are
hydrated carbons
general chemical formula of carbohydrates
CH2On, n = number of carbons
monosaccharides are
the simplest carbohydrate
polysaccharides are
the most complex carbohydrate
most common monosaccharide
glucose
nucleic acids are
biological macromolecules within cells that store genetic information
DNA is
a double stranded nucleic acid with each stand containing repeating units of deoxyribonucleotides linked together by phosphodiester bonds. Each deoxyribonucleotide contains either thymine, guanine, adenine, or cytosine nitrogenous bases
RNA is
a single stranded nucleic acid formed by repeating units of ribonucleotides bound by phosphodiester bonds. Each ribonucleotide contains either uracil, guanine, adenine, or cytosine nitrogenous bases
uracil is specific to
RNA
thymine is specific to
DNA
DNA and RNA are composed of
nucleotide monomers
nucleotides have three components:
pentose sugar
phosphate
nitrogenous base
six examples of protein function in the body
catalysis of reactions, through enzymes
structural support of cells
body movement
oxygen transport in the blood
membrane transport for molecules like glucose
immune protection, through antibodies
Proteins are polymers composed of
one or more linear strands of amino acid monomers
how many amino acids are there in the body that are used to form proteins?
20
what are the four structural hierachy of proteins?
primary
secondary
tertiary
quaternary
primary protein structure
single chains of peptide bonded amino acids with a carboxyl and amino terminal ends
secondary protein structure is characterized by
alpha helices and beta sheets
tertiary protein structure is
the final 3D shape by one protein chain
quaternary protein structure is
a structure of two or more proteins in 3D structure
denaturation is
when the conformation/structure of a protein is changed
what is the result of denaturation?
the biological activity of a protein ends or is disrupted
three ways denaturation can occur
extreme heat
extreme pH changes
addition of solvents
