Chapter 2
f an elemment is compowd of atoms with an atoemic number of 6 and a mas mumber of 14 then the nucleus ocf a neutral atom of this element containe
6 protons and 8 neutrons
the reaction listed below, what coefficient needs to be added to balance the equation? 6 CO2 + 6 H20 C6H1206+
8
Which of the following is both an anion and a compound?
HCO3-
In living cells, complex metabolic reactions proceed in a series of steps called
a metabolic pathway.
Elements that have atoms with full outer shells of electrons
are inert gases
Carbohydrate molecules
are the body's most readily available source of energy.
By weight, which element is the second most abundant in the human body?
carbon
The molecule CO2 is known as
carbon dioxide.
All fatty acids contain a functional group at one end called the group
carboxyl
In a molecule of oxygen gan, two pais of electrons ane shared equally by two oxygen atoms The type of bond that is formed is an example of a
double nonpolar covalent bond
Which of the following lists contains only trace elementa?
silicon, fluorine
one pair of electrons is unequally shared betwen two aboms, a loccurs
single polar covalent bond
A(n) is a homogeneous mixture containing a solvent and a solute.
solution
Which of the following are large polysaccharides and major dietary source of energy?
starch
Which of the following is a structural component of hormones?
steroids
Which of the following substances would be most acidie?
stomach secretions pH=1
The actual mas of an atom is known as its
umber atomic weight
lonic bonds are formed when
vdectrons are completely trandered from one aton to another
Hydrophilic molecules readily associate with
water molecules
In hydrolysis reactions, compounds react with
water, cusing decomposition
polysaccharide that is formed in muscle cells to store glucose is
glycogen.
Which of the following is correct regarding fructose?
h is an isomer of glucose.
Which of the following statements about water is not correct?
has a relatively low heat capacity
Oppositely charged ions in solution are prevented from combining by
hydration spheres.
The weakest bond between two atoms is the bond.
hydrogen
Which element commonly has only a proton as its nucleus?
hydrogen
The molecule H2 is known
hydrogen.
Molecules that do not readily dissolve in water are called
hydrophobic
Nonpolar organic molecules are good examples of
hydrophobic compounds.
Which of the following functional groups of organic compounds link molecules through dehydration synthesis?
hydroxyl group
Aboms of the same element numbers of neutrons are called whose nuclei contain the same number of petons, but diferen
isotopes
Which of the following is a chemical messenger coordinating local cellular activities?
leukotrienes
In dehydration reactions compounds
lose water molecules
Compounds that can be synthesized or broken down by chemical reactions inside the body are called
metabolites
H2O is an example of a(n)
molecular formula.
In an aqueous solution sodium ions would move toward
negative terminal.
A solution containing equal numbers of hydrogen ions and hydroxide lons is
neutral.
Isatopes of an element differ in the number of
neutrons in the nucleus
The center of an atom is called the
nucleus.
Carbohydrates, lipids, and proteins are classified as
organic molecules.
The chemical behavior of an atom is determined by the
outermost electron shell
The molecule O2 is known as
oxygen.
The of a solution is the negative logarithm of the hydrogen ion concentration expressed in moles per liter.
pH
Of the list below, which has the highest concentration of hydroxide ions?
pH 14
Which pH is closest to normal blood pHr
pH 7
Kinetic energy is stored as energy when a spring is stretched.
potential
Each of the following is an example of an inorganic compound except
proteins.
The "atomic number" of an atom is determined by the number of t has
protons
The mass of an atom is largely determined by the number of it has.
protons + neutrons
The atomic weight of an atom reflects the average number of
protons + neutrons + electrons.
The nucleus of an atom consists of
protons + neutrons.
The mass number represents the number of
protons neutrona
The innermost electron shell in an atom helds up to electns
2
compounds do not usually contain carbon as a primary structural atom.
Inorganic
molecules are compounds that contain carbon as the primary structural atom.
Organic
By weight, which element is the most plentiful in the human body?
Oxygen
accelerate chemical reactions that occur in the human body.
Enzymes
Of the following choices, the pH of the least acidic solution is
12.0.
lf an isotope of oxygen has 8 protons, 10 neutrons, and 8 electrons, its mass number is
18.
Magnesium atoms have two electrons in the outermost shell. As a result, you would expect magneslum to farm ions with a charge of
+2
Which of the following is the symbol for an amino group?
-NH2
Magnesium atoms have two electrons in their outermost shells, and chlorine atoms have seven. The compound magnesium chloride would contain
1 magnesium and 2 chlorine.
Which has the greater concentration of hydrogen ions, a substance with a pH of 5 or a substance with a pH of 4?
A pH of 4 is greater.
are soluble inorganic compounds whose solutions will conduct an electric current.
Enzymes
An excess of hydrogen ions in the body fluids can have fatal results because this can
All of the answers are correct.
Which of the following is not a cation?
Cl-
Which of the following statements about hydrogen bonds is false?
Hydrogen bonds are strong attractive forces between hydrogen atoms and negatively charged atoms.
An important buffer in body fluids is
NaHCO3.
When a small amount of HCl or NaOH is added to a solution of Na2HPOL the pH of the solution barely changes. Based on these observations, all of the following are true conceming the compound NazHPO except
NagHIO adsorbs excess H and OH- directly onto the surface of its crystalline structure
in chemical notation, the symbol Ca2+ meana
a calaum son that has lost two electrons.
When two monosaccharides undergo a dehydration synthesis,
a disaccharide is formed.
If a substance has a pH that is greater than 7, it is
alkaline.
When electrons are transferred from one atom to another, and the two atoms unite as a result of the opposite charges,
an ionic bond is formed.
In an aqueous solution, cations are attracted toward
anions
lonu with a negative charge are called
anions
All of the following are true concerning enzymes except that they
are consumed during the reaction.
A functional group is best described as reoccurring clusters of
atoms that greatly influence the chemical properties of molecules they are part of.
The smallest stable units of matter are
atoms.
A(n) removes hydrogen ions, and a(n). releases hydrogen ions.
base; acid
Which of the following is/are inorganic substance(s)?
both water and carbon dioxide
In the body, inorganic compounds
can serve as buffers.
The group of organic compounds containing carbon, hydrogen, and oxygen in a near 121 ratio is defined as
carbohydrate
lons with a + charge are called
cations
Oxygen is requined in biological aystema for
cellular respiration
Which of the following is a structural component of cell membranes?
cholesterol
When atoms complete their outer electron shell by sharing electrons, they form
covalent bonds
During ionization, water molecules disrupt the lonic bonds of a salt to produce a mixture of ions. These ions can carry a current and so are called
electrolytes.
A(n) is a pure substance composed of atoms.
element
Chemical reactions that absorb energy are called
endergonic
The reaction A.B. energy- AB is an example of atn)
endergonic reaction.
Chemical reactions that release energy are called
exergonic.
Chemical reactions that yield energy, such as heat, are said to be
exergonic.
The three familiar states of matter listed in order from the least to most thermal energy are
gas, liquid, solid.
The most important metabolic fuel molecule in the body is
glucose.
When placed in water, an inorganic compound dissociates 99 percent, forming hydrogen ions and anions. This compound would be a
strong acid.
A dust particle floating on a water surface illustrates
surface tension.
The reaction N2 3 Hg2 NHs is an example of an)
synthesis reaction
ABA. B is to decomposition as A B AB is to
synthesis.
Which property of water helps keep body temperature stabilized?
thermal inertia
Which one of the following must be broken down to fatty acids and glycerol for use as an energy source?
triglycerides
