Chapter 2 (I) Flashcards
what cannot be broken down into simpler substances by ordinary chemical methods?
elements
what are the unique building blocks for each element and give each element its physical and chemical properties?
atoms
what 4 elements make up 96.1% of body mass?
carbon, hydrogen, oxygen, and nitrogen
what is the purpose of carbon, hydrogen, oxygen, and nitrogen?
they are the structure of biomolecules
what 9 elements make up 3.9% of body mass?
calcium, chlorine, magnesium, sulfur, iodine, potassium, sodium, iron, and phosphorous
what elements generate electric potentials of cells?
sodium and potassium
what element is involved in cell signaling, muscle contraction, and bone mineralization?
calcium
what element stores chemical energy for cell processes?
phosphorous
the 11 elements that make up less than 0.01% of body mass are part of/activate what?
enzymes
what is composed of subatomic particles?
atoms
where are protons and neutrons found?
nucleus
where are electrons found?
orbiting the nucleus
the number of protons and electrons are always ______.
equal
what model is simplified/outdated and incorrectly depicts fixed circular electron paths around the nucleus?
planetary model
what model is current/used by chemists, depicts probable regions of greater electrons density, and predicts chemical behavior of atoms?
orbital model
atomic number
number of protons in nucleus
mass number
total number of protons and neutrons in nucleus
what has structural variations of atoms and differ in the number of neutrons they contain?
isotopes
atomic weight
average of mass numbers of all isotopes of an atom
radioisotopes
heavy isotopes decompose to more stable forms
spontaneous decay is called what?
radioactivity
what can be detected with a scanner (PET scan)?
radioisotopes
why are radioisotopes valuable tools?
for biological research and medicine and diagnosis
what damages living tissue and can destroy localized cancers?
radioisotopes
molecule vs compound
molecule: made up of 2/more atoms bonded together
compound: 2/more different kinds of atoms bonded
most matter exists as
mixtures
what are the 3 types of mixtures?
solutions, colloids, and suspensions
solutions
homogeneous
gas, liquid, solid dissolved in water
transparent
concentration of solutions can be expressed as what?
percent of solute in total solution
milligrams per deciliter
molarity (mol/L)
colloids
heterogeneous
large solute particles that do not settle out
sol-gel transformations
suspensions
heterogeneous
large, visible solutes settle out
what has no chemical bonding between components, can be separated by physical means, and is either homogeneous or heterogeneous?
mixture
what has chemical bonding between components, can be separated only by breaking bonds, and are all homogeneous?
compounds
chemical bonds
energy relationships between electrons
what type of electrons have the most potential energy and are all chemically reactive?
valence electrons
what elements are stable, un-reactive, have a fully occupied valence shell, and are noble gases?
chemically inert elements
what elements have an unfilled valence shell and tend to gain, lose, or share electrons with other atoms to achieve stability?
chemically reactive elements
what are true bonds? what are not true bonds?
true bonds: ionic and covalent bonds
not true bonds: hydrogen bonds
what is an atom that gains or loses electrons and becomes charged?
ions
ionic bonds
transfer valence shell electrons from 1 atom to another to form ions
attraction of opposite charges result in a bond
in an ionic bond the metal gives to the nonmetal, making the metal a _______ and nonmetal a ______.
metal= cation nonmetal= anion
most ionic compounds are ______.
salts
dry salts form ______ instead of individual molecules.
crystals
covalent bonds
share 2 or more valence shell electrons
deals mostly with nonmetals
20 amino acids are similar except in their “R” group. what does this mean in an organic chemistry context?
always know what these atoms are going to do
amino acids are linked together by what kind of reaction and form what type of bonds?
linked together by dehydration synthesis
form peptide bonds
nonpolar covalent bonds
electrons shared equally
electrically balanced
how do you breathe out carbon dioxide?
carbon dioxide cannot dissolve in the blood so it converts to its ionic form (bicarbonate) to get it dissolved in the blood and return to the lungs
polar covalent bonds
unequal sharing of electrons
produce dipole molecules
small atoms with 6 or 7 valence shell electrons are _______ and atoms with 1 or 2 valence shell electrons are _______.
6/7 valence shell electrons = electronegative
1/2 valence shell electrons = electropositive
hydrogen bonds
attractive force between electropositive hydrogens and electronegative atoms
hydrogen bonds act as ______ bonds, holding a large molecule in a 3D shape.
intramolecular
what bond results in high surface tension of water?
hydrogen bonds
chemical reactions occur when chemical bonds are ______, ______, or ______.
formed, rearranged, or broken
what reactions combine to form larger, more complex molecule and always involve bond formation?
synthesis reactions
amino acids are joined together to form a protein molecule is an example of what reaction?
synthesis
what reactions break down into smaller molecules?
decomposition reactions
glycogen breaking down to release glucose units is an example of what reaction?
decomposition
what reactions are also called displacement reactions and involve both synthesis and decomposition?
exchange reactions
ATP transferring its terminal phosphate group to glucose to form glucose phosphate is an example of what reaction?
exchange
what reactions are both decomposition reactions and exchange reactions?
redox reactions
glucose being oxidized and oxygen being reduced in glycolysis is an example of what reaction?
redox
what reaction has a net release of energy, with products that have less potential energy than reactants, and are catabolic/oxidative reactions?
exergonic reactions
what reaction has a net absorption of energy, with products that have more potential energy than reactants, and are anabolic reactions?
endergonic reactions
how do you speed up an endergonic reaction? how do you speed up an exergonic reaction?
endergonic: give reaction heat
exergonic: take away heat (ice bath)
all chemical reactions are theoretically ______ and many biological reactions are essentially ______.
chem rxns: reversible
bio rxns: irreversible
why are biological reactions irreversible?
energy requirements and removal of products
how do you increase rate of reaction?
increased temperature and concentration
decreased particle size
catalysts
what are catalysts?
increase rate without being chemically changed/part of product
