Ch. 2 Outcome-Based Questions The Chemical Level of Organization
To maintain homeostasis in the body, the normal pH range of the blood must remain at
7.35 to 7.45.
Which of the following is a synthesis reaction?
A+B--> AB.
The most important high-energy compound in cells is
ATP.
The chemical notation that indicates "one molecule of hydrogen composed of two hydrogen atoms" is
H2.
which one of the following molecules is drawn correctly to show the proper covalent bonding?
N=N
The nitrogen base found in RNA but not in DNA is
Uracil
A decomposition reaction is one in which
a molecule is broken down into smaller fragments.
A solution with a pH below 7 is
acidic.
The high-energy compound produced by the body is __________ triphosphate.
adenosine
If a substance has apH greater than 7, it is
alkaline or basic.
Proteins differ from carbohydrates in that they
always contain nitrogen.
The building blocks of proteins consist of chains of small molecules called
amino acids.
A solute that dissociates to release hydrogen ions and causes a decrease in pH is
an acid.
The activation energy requirement of a reaction is much lower in the presence of
an appropriate enzyme.
Synthesis of new compounds in the body
anabolism.
The smallest units of matter whose identities cannot be altered by a chemical change are
atoms.
A solute that removes hydrogen ions from a solution is a
base.
Inorganic ions are important in the function of
blood clotting, muscle contractions, and nerve impulse conduction.
A substance that helps stabilize pH is called a
buffer.
Resists change in pH
buffer.
Compounds that stabilize pH by either removing or replacing hydrogen ions are
buffers.
Organic compounds differ from inorganic compounds in that organic compounds are primarily composed of
carbon and hydrogen atoms and are much larger and more complex.
An example of a weak acid that serves as an effective buffer in the body is
carbonic acid.
Decomposition reaction within cells
catabolism.
The decomposition reaction of complex molecules within cells is called
catabolism.
Enzymes belong to a class of substances called ________, which accelerate chemical reactions without themselves being permanently changed.
catalysts.
Positively charged ion
cation.
Ions with a positive charge are called
cations.
Chemicals form functional units called
cells.
The number and arrangement of electrons determine the
chemical behavior of an atom.
any chemical substance made up of atoms of two or more elements, regardless of how the atoms achieve stability, is a
compound.
atoms that complete their outer shells by sharing electrons with other atoms result in molecules held together
covalent bond.
DNA contains the five-carbon sugar
deoxyribose.
During ionization, water molecules disrupt the ionic bonds of a solute and a mixture of ions is produced. These ions are called
electrolytes.
Soluble inorganic compounds whose ions will conduct an electric current in solution are
electrolytes.
A chemical ________ is a substance that consists entirely of atoms with the same atomic number.
element
The areas surrounding the center of an atom represent ________ levels.
energy
Carbohydrates are most important to the body because they serve as primary sources of
energy.
Acts as a catalyst to speed up chemical reaction
enzyme.
Special proteins that are involved in metabolic regulation are called
enzymes.
When the rate of a synthesis reation balances the rate of a decomposition reactions, the result is
equilibrium.
Shuffling around of reacting molecule
exchange reaction.
Exergonic reactions, which are common in the body, are responsible for
generating the heat that maintains your body temperature.
The disaccharide sucrose consists of fructose bonded to
glucose.
The most important metabolic fuel molecule in the body is
glucose.
The polysaccharide formed by stored glucose in the liver and muscle is
glycogen.
In DNA and RNA, a nucleotide containing the nitrogen base cytosine would only base-pair with
guanine
The greater the concentration of ________ ions in solution, the lower the pH.
hydrogen
pH is a measure of the concentration of _________ in solution.
hydrogen ions
Acids, bases, and salts are examples of _______ compounds.
inorganic
A salt may best be described as an
inorganic molecule created by the reaction of an acid and a base.
An atom or molecule that has a positive or a negative charge is a
ion.
When one atom loses an electron and another accepts that electron, the result is the formation of an
ionic bond.
The attraction of cations to anions illustrates the formation of
ionic bonds.
Two atoms of same element with different number of neutrons
isotope.
Tow atoms that have the same number of protons but a different number of neutrons are called
isotopes.
Energy of motion
kinetic energy.
A steroid molecule is an example of a
lipid.
Fats and steroids are examples of
lipids.
The prontons and neutrons of an atom determine the
mass number of an atom.
Chemical structures that contain more than one atom bonded together by shared electrons are
molecules.
When a chemical reation occurs, the chemical structures that contain more than one atom are called
molecules.
Each amino acid differs from others in the
nature of the R group.
When phosphorus become an ion, it exhibits a _________ charge.
negative
A solution with a pH of 7 that contains equal numbers of hydrogen ions and hydroxide ions is called
neutral.
The mass number of an atom changes if its number of ________ changes.
neutrons
Isotpes of an element differ in the number of
neutrons in the nucleus.
The molecules that store and process information at the molecular level are the
nucleic acids.
The synthesis of all cellular proteins is directed by
nucleic acids.
Neutrons and protons are located in the _________ of an atom.
nucleus
The center of an atom is called the
nucleus.
The symbol Na+ refers to
one sodium ion (has lost an electron).
Compounds that contain the elements carbon, hydrogen, and usually oxygen are ______ compounds.
organic
The attachment of a carboxylic acid group of one amino acid to the amino acid group of another forms a connection called a
peptide bond.
Unequal sharing of a pair of electrons between two atoms forms a
polar covalent bond.
when an atom loses an electron, it exhibits a _________ charge.
positive
Stored energy
potential energy.
The atomic number represents the number of
prontons and neutrons.
A _______ consists of a chain of molecules called amino acids.
protein
The chemicals that form an internal supporting framework and act as enzymes to accelerate and control the chemical reactions that maintain homeostasis are
protein.
The subatomic particles found in the nucleus of an atom include
protons and neutrons.
The three subatomic particles that are stable constituents of atomic structures are
protons, neutrons, and electrons.
when an enzyme promotes a chemical reaction by lowering the activation energy, it only affects the
rate of the reaction.
Butter, fatty meat, and ice cream are examples of sources of tatty acids that are said to be
saturated.
In the body, inorganic compounds
serve as buffers.
Dissolved material in solution
solute.
Most chemical reactions in the body take place in
solution.
a homogenous mixture containing a solvent and a solute is called a
solution.
Liquid portion of solution
solvent.
Special molecules called enzyme found in cell
speed up the reactions that support life.
The substance that is acted upon by an enzyme
substrate.
The three basic components of a single nucleotide of a nucleic acid are
sugar, phosphate group, and nitrogen base.
Most of the fat found in the human body is in the form of
triglycerides.
The symbol 2H means
two atoms of hydrogen.
The balanced equation 2H2 + O2--> 2H2O means that
two molecules of hydrogen and one molecules of oxygen have combined chemically to form two molecules of water.
Which of the following substances would be the least acidic?
urine with a pH of 6.
The unique property of water that is particularly important to the human body include
water has a very high heat capacity.
The most important inorganic compound found in large quantity in the body is
water.
