Chapter 2 - The Chemical Basis of Life Flashcards
the scientific discipline concerned with the atomic composition and structure of substances and the reactions they undergo.
Chemistry
About _______ of the body’s weight results from the elements oxygen, carbon, hydrogen, and nitrogen.
96%
do not have an electrical charge
neutrons
have positive charges
protons
have negative charges
electrons
The nucleus accounts for 99.97% of an atom’s mass, but only 1-ten- a trillionth of its volume. True or False
True
The chemical behavior of an atom is not dependent on its electrons. True or False
False (dependent)
__________ is the ability of the atom’s nucleus to pull electrons toward it.
Electronegativity
a charged particle
ion
sharing of one pair of electrons by two atoms
single covalent bond
two atoms share two pairs of electrons
double covalent bond
an unequal, asymmetrical sharing of electrons
polar covalent bond
Molecules with this asymmetrical electrical charge
polar molecules
an equal sharing of electrons between atoms, it is because their electronegativities are the same
nonpolar covalent bond
Molecules with a symmetrical electrical charge
nonpolar molecules
The positive end of one polar molecule can be weakly attracted to the negative end of another polar molecule
hydrogen bond
All compounds are molecules. True or False
False (Some compounds are molecules and some are not)
dissociated ion
electrolytes
The formation or breaking of chemical bonds between atoms, ions, molecules, or compounds
chemical reaction
The substances that enter into a chemical reaction
reactants
The substances that result from the chemical reaction
products
When two or more reactants combine to form a larger, more complex product, the process is called a ______________
synthesis reaction
All of the synthesis reactions that occur in the body are collectively referred to as _____
anabolism
Synthesis reactions in which water is also a product are called __________
dehydration reactions
reactants are broken down into smaller, less complex products
decomposition reaction
The decomposition reactions that occur in the body
catabolism
Reactions that use water
hydrolysis reactions
All of the anabolic and catabolic reactions in the body
metabolism
An __________ is a combination of a decomposition reaction and a synthesis reaction.
exchange reaction
the reaction can run in the opposite direction so that the products are converted back to the original reactants.
reversible reaction
the rate of product formation is equal to the rate of reactant formation
equilibrium
stored energy
Potential energy
caused by the movement of an object and is the form of energy that actually does work
Kinetic energy
a form of potential energy stored in chemical bonds
chemical energy
According to the law of conservation of energy, the total energy of the universe is inconsistent. True or False
False (constant)
___________ is energy resulting from the position or movement of objects.
Mechanical energy
If blood pH drops below 7.35, a condition called _______ results
acidosis
If blood pH rises above 7.45, _________ results
alkalosis
a chemical that resists changes in pH
buffer
organic chemistry deals with those substances that do not contain carbon, whereas inorganic chemistry is the study of carbon-containing substances. True or False.
False (inorganic, organic)
simplest carbohydrates
monosaccharides
formed when two monosaccharides are joined by a covalent bond
disaccharides
consist of many monosaccharides bound in long chains
polysaccharides
a polysaccharide of glucose
glycogen
substances that dissolve in nonpolar solvents, such as alcohol or acetone, but not in polar solvents, such as water.
lipids
a protein catalyst that increases the rate at which a chemical reaction proceeds without the enzyme being permanently changed
enzyme
