Chapter 2 Flashcards
Matter
is anything that occupies space and mass
Mass
The amount of matter in the object
Weight
Results from the force exerted by the earth’s gravity on matte
Element
simplest type of matter having unique chemical and physical properties.
An atom
is the smallest particle of an element that has the chemical characteristics of that element. An element is composed of only one kind of atom.
Atoms
consist of protons, neutrons, and electrons.
The atomic number
is the unique number of protons in an atom.
Isotopes
are atoms that have the same atomic number but different mass numbers.
The chemical behavior of atoms
is determined mainly by their outermost electrons.
A chemical bond
occurs when atoms share or transfer electrons.
Ions
Atoms that have gained (anions) or lost (cations) electrons.
Ionic bond
results from the attraction of the oppositely charged cation and anion to each other
A covalent bond
forms when electron pairs are shared between atoms
A polar covalent bond
results when the sharing of electrons is unequal and can produce a polar molecule that is electrically asymmetric.
A molecule
two or more atoms chemically combined to form a structure that behaves as an independent unit.
A compound
is two or more different types of atoms chemically combined.
The molecular mass
of a molecule or compound can be determined by adding up the atomic masses of its atoms (or ions).
Hydrogen bond
A hydrogen bond is the weak attraction between a positively charged hydrogen and negatively charged oxygen or another polar molecule.
Solubility
Ability of one substance to dissolve in another.
electrolytes.
Ionic substances that dissolve in water by dissociation are
nonelectrolytes.
Molecules that do not dissociate are
A synthesis reaction
is the chemical combination of two or more substances to form a new or larger substance
A dehydration reaction
is a synthesis reaction in which water is produced.
Anabolism.
The sum of all synthesis reactions in the body is called
A decomposition reaction
is the chemical breakdown of a larger substance to two or more different and smaller substances.
A hydrolysis reaction
is a decomposition reaction in which water is depleted.
Catabolism.
The sum of all the decomposition reactions in the body
Oxidation-reduction reactions
involve the complete or partial transfer of electrons between atoms.
Energy
The ability to do work
Potential energy
stored energy,
kinetic energy
energy resulting from the movement of an object
Enzymes
specialized protein catalysts that lower the activation energy (minimum energy to start a chemical reaction) for chemical reactions.
A mixture
is a combination of two or more substances physically blended together, but not chemically combined.
A solution
is any liquid, gas, or solid in which the substances are uniformly distributed, with no clear boundary between the substances.
A solute
dissolves in a solvent.
A suspension
is a mixture containing materials that separate from each other unless they are continually, physically blended together.
A colloid
is a mixture in which a dispersed (solutelike) substance is distributed throughout a dispersing (solventlike) substance. Particles do not settle out of a colloid.
Acids
proton (H+) donors, have pH values less than 7.
Bases
are proton acceptors, have PHs more than 7
A buffer
is a solution of a conjugate acid-base pair that resists changes in pH when acids or bases are added to the solution.
Organic molecules
contain carbon and hydrogen atoms bound together by covalent bonds.
Monosaccharides
are the basic building blocks of other carbohydrates. Examples are ribose, deoxyribose, glucose, fructose, and galactose. Glucose is an especially important source of energy.
Disaccharide molecules
are formed by dehydration reactions between two monosaccharides. Examples of disaccharides are sucrose, lactose, and maltose.
A polysaccharide
composed of many monosaccharides bound together to form a long chain. Examples include cellulose, starch, and glycogen
Triglycerides (fats)
) are composed of glycerol and fatty acids and store energy. Fatty acids are straight chains of carbon molecules with a carboxyl group. Fatty acids can be saturated (single covalent bonds) or unsaturated (double covalent bonds).
Phospholipids
are lipids in which a fatty acid is replaced by a phosphate-containing molecule. Phospholipids are a major structural component of plasma membranes.
Steroids
are lipids composed of four interconnected ring molecules. Examples are cholesterol, bile salts, and sex hormones.
The building blocks of a protein
are amino acids, which are joined by peptide bonds. The number, kind, and arrangement of amino acids determine the primary structure of a protein.
A gene
is a sequence of DNA nucleotides that determines the structure of a protein or RNA.
Adenosine triphosphate (ATP)
stores energy derived from catabolism. The energy released from ATP is used in anabolism and other cell processes.
Chemistry
The study of the composition, structure, and reactions of matter.
Carbohydrates
Provides majority of energy that cells require
Lipids
Supplies the energy that the body uses to generate cells
Nucleic acids
Building blocks of proteins and genetic material, giving instructions that control cells activities
Proteins
Structural materials, energy providers, and chemical messengers
