Ch 2. Chemistry Comes Alive Flashcards
Anything that occupies space
Matter
Capacity to do work
Energy
Energy in action
Kinetic energy
Stored energy; energy that has the capability to do work
Potential energy
The form of energy stored in the bonds of chemical substances
Chemical energy
Energy that results from the movement of charged particles
Electrical energy
Energy directly involved in moving matter
Mechanical energy
Energy that travels in waves
Radiant energy (electromagnetic radiation)
Unique substances that cannot be broken down into simpler substances by ordinary chemical methods
Elements
The first letters of the element’s name
Atomic symbol
A simplified model of atomic structure
Planetary model
Regions around the nucleus in which a given electron or electron pair is likely to be found most of the time
Orbitals
Depicts probable regions of greatest electron density by denser shading
Orbital model
Number of protons in an atom
Atomic number
The sum of the masses of an atom’s protons and neutrons
Mass number
Atoms with the same number of protons, but different number of neutrons
Isotopes
An average of the relative weights of all the isotopes of an element, taking into account their relative abundance in nature
Atomic weight
Unstable isotopes where atoms decompose spontaneously into more stable forms
Radioisotopes
Two or more atoms of the same element held together by chemical bonds are…
Molecules
When two or more different kinds of atoms bind they form a …
Compound
Substances composed of two or more components physically intermixed
Mixtures
Homogeneous mixtures of components that may be gases, liquids, or solids
Solutions
The substance present in the greatest amount (dissolving medium)
Solvent
Substances present in smaller amounts (dissolved in the solvent)
Solutes
Moles per liter; way to express a concentration of a solution
Molarity
Heterogeneous mixtures; composition is dissimilar in different areas of the mixture
Colloids (emulsions)
To change reversibly from a fluid (sol) state to a more solid (gel) state
Sol-gel transformations
Heterogeneous mixtures with large, often visible solutes that tend to settle out
Suspensions
An energy relationship between the electrons of the reacting atoms and it is made or broken in less than a trillionth of a second
Chemical bonds
An atom’s outermost energy level or that portion of it containing the electrons that are chemically reactive
Valence shell
After the first shell is full with 2 electrons, each energy shell can only contain up to 8 electrons
Octet rule
Atoms with a charge
Ions
A chemical bond between atoms formed by the transfer of one or more electrons from one atom to the other
Ionic bond
The electron acceptor, that acquires a negative charge is called…
Anion
The electron donor, that acquires a positive charge is called…
Cation
Large arrays of cations and anions held together by ionic bonds
Crystals
A bond where electrons are shared and occupy a single orbital common to both atoms
Covalent bond
Electrically balanced molecules
Nonpolar molecules
Unequal electron pair sharing
Polar molecules
The capability to strongly attract electrons (electron-hungry)
Electronegativity
Atoms with only one or two valence shell electrons are…
Electropositive
Another name for a polar molecule; an atom that has two poles of charge
Dipole
Whenever chemical bonds are formed, rearranged, or broken
Chemical reaction
The number and kinds of the interacting substances
Reactants
The chemical composition of the result of the reaction
Products
When atoms or molecules combine to form a larger, more complex molecule (bond formation)
Synthesis or combination
When a molecules is broken down into smaller molecules or its constituent atoms
Decomposition reaction
Constructive activities in body cells
Anabolic
Degradative processes in body cells
Catabolic
Reactions that involve both synthesis and decomposition
Exchange or displacement reactions
Decomposition reactions that are the basis of all reactions in which food fuels are broken down for energy
Redox reactions
The reactant losing the electrons is the electron donor and is said to be…
Oxidized
The reactant taking up the transferred electrons is the electron acceptor and is said to become…
Reduced
Reactions that release energy
Exergonic reactions
Reactions that absorb energy and contain more potential energy in their chemical bonds than did the reactants
Endergonic reactions
When neither the forward reaction nor the reverse reaction is dominant
Chemical equilibrium
Compounds that contain carbon and are covalently bonded molecules
Organic compounds
All other chemicals in the body; includes water, salts, and many acids and bases
Inorganic compounds
Water is often called…
The universal solvent
Layers of water molecules around large charged molecules such as proteins, shielding them from the effects of other charged substances in the vicinity and preventing them from settling out of solution
Hydration layers
An ionic compound containing cations other than H+ and anions other than the hydroxyl ion (OH-)
Salt
Substances that conduct an electrical current in solution
Electrolytes
A substance that releases hydrogen ions in detectable amounts; proton donors
Acids
Substances that take up hydrogen ions in detectable amounts; proton acceptors
Bases
An important base in the body that is particularly abundant in blood
Bicarbonate ion (HCO3-)
A common waste product of protein breakdown in the body (base)
Ammonia (NH3)
When acids and bases are mixed they react with each other in displacement reactions to form water and a salt. This is called…
Neutralization reactions
These resist abrupt and large swings in the pH of body fluids by releasing hydrogen ions when the pH begins to rise and by binding hydrogen ions when the pH drops
Buffers
A major buffer system that helps to maintain pH homeostasis of the blood
Carbonic acid-bicarbonate system
The property that neither desires to take or give away electrons
Electroneutral
Chainlike molecules made of many smaller, identical or similar units
Polymers
The process by which a hydrogen atom is removed from one monomer and a hydroxyl group is removed from the monomer it is to be joined with. As a covalent bond unites the monomers, a water molecule is released.
Dehydration synthesis
In these reactions, a water molecule is added to each bond to be broken down, thereby releasing its building blocks or smaller molecules
Hydrolysis
A group of molecules that includes sugars and starches and contains carbon, hydrogen, and oxygen
Carbohydrates
Simple sugars that are single-chain structures containing from 3 to 7 carbon atoms
Monosaccharides
Double sugars that are formed when two monosaccharides are joined by dehydration synthesis
Disaccharides
Structures with the same molecular formula, but with atoms that are arranged differently, giving them different chemical properties
Isomers
Polymers of simple sugars linked together by dehydration synthesis
Polysaccharides
A polysaccharide found in hall plant products. It is important in providing the bulk that helps move feces through the colon
Cellulose
The storage carbohydrate of animal tissues, is stored primarily in skeletal muscle and liver cells
Glycogen
Organic compound formed of carbon, hydrogen, and oxygen; examples are fats and cholesterol
Lipids
Fats when solid or oils when liquid. They provide the body’s most efficient and compact form of stored energy, and when they are oxidized, they yield large amounts of energy
Triglycerides (neutral fats)
Fatty acid chains with only single covalent bonds between carbon atoms are referred to as saturated
Saturated
Fatty acids that contain one or more double bonds between carbon atoms
Unsaturated
Oils that have been solidified by addition of H atoms at sites of carbon double bonds
Trans fats
Diglycerides with a phosphorus-containing group and two, rather than three, fatty acid chains
Phospholipids
Flat molecules made of four interlocking hydrocarbon rings. They are fat soluble and contain little oxygen
Steroids
Diverse lipids chiefly derived from a 20-carbon fatty acid found in all cell membranes
Eicosanoids
Building blocks of proteins
Amino acids
Composes 10-30% of cell mass`
Protein
Long chains of amino acids joined together by dehydration synthesis
Peptide bond
Large, complex molecules containing from 100 to over 10,000 amino acids
Macromolecules
Extended and strandlike proteins that are insoluble in water and very stable
Fibrous proteins (structural proteins)
Compact, spherical proteins that are water-soluble, chemically active molecules and they play crucial roles in virtually all biological processes
Globular proteins (functional proteins)
When proteins unfold and lose their specific three-dimensional shape it is said to be…
Denatured
Functional enzyme
Holoenzyme
The part of the enzyme where catalytic activity occurs
Active site
The substance on which an enzyme acts
Substrate
Every chemical reaction requires that a certain amount of energy be absorbed to prime the reaction. This energy is called…
Activation energy
Molecules composed of carbon, oxygen, hydrogen, nitrogen, and phosphorus that are the largest molecules in the body
Nucleic acids
The structural units of nucleic acids
Nucleotides
The primary energy-transferring molecule in cells and it provides a form of energy that is immediately usable by all body cells
Adenosine triphosphate (ATP)
Bases of DNA that always bond to each other
Complementary bases
