This activity contains 25 questions.
The chemical behavior of an atom is determined by
its mass.
its electrons.
its neutrons.
its protons.
How many electrons would carbon have in its outermost shell? (Hint:
Carbon has an atomic number of 6.)
3
5
6
4
If a neutral atom becomes a negative ion, it
loses electrons.
gains protons.
gains electrons.
loses protons.
A bond formed by the sharing of electrons between atoms is called a(n)
_________ bond.
hydrogen
isometric
covalent
ionic
An element with an unfilled outermost energy level is called
a gas.
an ion.
inert.
reactive.
A decomposition reaction is
the assemblage of smaller molecules into larger molecules.
the transfer of components from one molecule to another.
a chemical reaction that requires the continuous addition of energy
to proceed.
the breakdown of a molecule into smaller components.
What happens to an enzyme that is exposed to extreme temperatures
(outside its normal range)?
It denatures the enzyme.
It does not affect the enzyme.
It catalyzes a reaction faster than before.
It turns the enzyme into a carbohydrate.
Enzymes act by
making a chemical reaction occur more slowly.
raising the energy of activation of a chemical reaction.
changing the equilibrium point of a chemical reaction.
lowering the energy of activation of a chemical reaction.
Which of the following statements about the properties of water is NOT
true?
It freezes at zero degrees Centigrade.
It dissolves many substances.
It is a nonpolar molecule.
It has a high specific heat.
What type of protein shape is characterized by the alpha helix or a flatpleated sheet?
Primary structure
Tertiary structure
Secondary structure
Quaternary structure
The more acidic a solution is,
the more stable its pH.
the more hydroxide ions it has.
the higher its pH.
the more hydrogen ions it has.
Buffers
protect us against parasitic worms.
raise the pH of solutions.
speed up chemical reactions.
maintain an almost constant pH.
Which of the following pH values represents the most acidic solution?
9
2
7
5
A salt is composed of
any cation (except hydrogen) and any anion (except hydroxide).
covalent bonds.
the parts of any inorganic substance.
a sodium compound and a chloride compound.
Acidosis occurs when
blood pH is between 7.35 and 7.45.
blood pH is above 7.45.
blood pH is below 7.35.
blood pH is exactly at 7.8.
What happens when you mix HCl (a strong acid) with NaOH (a strong
base)?
They create an even stronger acid.
They produce an even stronger base.
They produce excess salts in the system.
They neutralize each other.
Steroids are important for all the following reasons EXCEPT
they are important in the maintenance of cell membranes.
they are involved in the regulation of sexual function.
they are important in insulating and slowing heat loss.
they are important in the regulation of tissue metabolism and
mineral balance.
Glucose is a
polysaccharide.
disaccharide.
monosaccharide.
salt.
Glycogen is a
monosaccharide.
polysaccharide.
disaccharide.
salt.
Which of the following is NOT true about lipids?
They play an important role in forming cell membranes.
They readily dissolve in nonpolar solvents.
They contain less energy per gram than carbohydrates.
They are almost insoluble in water.
A compound consisting of more than 100 amino acids is known as a
lipid.
nucleic acid.
carbohydrate.
protein.
In living organisms, proteins perform which of the following function(s)?
Provide support
Transmit information (hormones)
Protect against disease
All of the above
The primary energy currency of living cells is
cyclic AMP.
DNA.
ATP.
ADP.
Which nucleic acid contains our genetic traits and determines our inherited
characteristics?
ATP
ADP
RNA
DNA
Polysaccharides are made up of many monosaccharides, and proteins are
made up of amino acids. What are the units of nucleic acids called?
Phospholipids
Glycoproteins
Nucleotides
Amino acids
This activity contains 14 questions.
What aspect of an atom determines its chemical properties?
Nucleus
Number of radioisotopes an atom has
Outermost energy level
Atomic weight
Which of the following statements about the chemical elements of the body
is NOT correct?
Potassium is important in proper membrane function.
By percentage of body weight, hydrogen is the most common
element in the human body.
All organic molecules contain carbon.
Nitrogen is important in all proteins and nucleic acids.
Sulfur is found in many proteins.
Calcium is important for nerve impulses and muscle contraction.
Which of the following is NOT a characteristic of covalent bonds?
Covalent bonds can share their electrons equally or unequally.
Covalent bonds help to create the surface tension of water.
Carbon dioxide is held together by covalent bonds.
Covalent bonds are very strong.
If a substance has a definite volume, but no definite shape, it is classified
as a __________.
solid
gas
liquid
Which of the following is NOT a characteristic of a decomposition
reaction?
Breaking chemical bond(s)
Releasing of kinetic energy
Catabolism
Building larger molecule from smaller ones
Which of these statements about basic energy concepts is NOT true?
Thermal energy is an increase in random molecular motion.
Potential energy is stored energy.
Energy is the capacity to perform work.
Kinetic energy is produced from potential energy when a book falls
from a shelf.
Work is the ability to perform a chemical reaction.
Which of the following statements about chemical reactions is NOT
correct?
A synthesis reaction that produces a molecule of water is called
hydrolysis.
When the concentration of reactants rises, the rate of the reaction
will increase.
At equilibrium, a synthesis reaction and a decomposition reaction
occur at a balanced rate.
Many important biological reactions are freely reversible.
Synthesis reactions always involve the formation of new chemical
bonds.
Which of these statements about water is NOT true?
Water allows rapid changes in body temperature by moving heat in
the blood.
Water's polar covalent bonds allow formation of hydrogen bonds
between water molecules.
Water is an unusually effective solvent.
Water containing dissolved ions conducts electricity effectively.
Evaporation of water removes heat from the body's surface as sweat
dries.
Which one of these statements about pH is correct?
An acidic solution has at least 1% hydrogen ions in it.
A basic or alkaline solution has more hydroxide ions than hydrogen
ions.
The pH scale ranges from 1 to 14.
The pH of a neutral solution is between pH 6 and pH 8.
Which of these inorganic compounds is NOT correctly related to its
function in the body?
HCl and NaOH are important in buffering the pH of the blood.
Buffering systems in the body usually consist of a weak acid and its
salt, which acts as a weak base.
Hydrochloric acid is produced by cells of the stomach for digestion
of food.
KCl and CaCl2 are important electrolytes that dissociate in body
fluids.
Some salts may ionize in body fluids to make the solution slightly
acidic or basic.
What is the primary function of carbohydrates such as monosaccharides
and disaccharides?
Storing the genetic information of the human body
Catalyzing chemical reactions
Serving as the main structural components of cell membranes
Serving as an important energy source
Helping to break down nutrients and damaged structures inside the
cells
Which of the following statements about enzymes is NOT correct?
Organic cofactors, or coenzymes, are often produced from vitamins
in the diet.
A cofactor is only effective in allowing substrate binding when the
cofactor binds to an enzyme's active site.
Reactants (substrates) are converted into products after binding to
the active site of the appropriate enzyme.
Cofactors such as calcium or magnesium ions are required by some
enzymes before substrate binding can occur.
Isozymes are enzymes that differ in structure but catalyze the same
reaction.
Temperature and pH extremes cause denaturation of enzymes by
changing primary sequence of the proteins.
Which of the labeled structures determines an enzyme's specificity?
Active site
Substrates
Product
See illustration from question 13. This reaction would be classified as a
(an) _____________ reaction.
decomposition
synthesis
catabolic
This activity contains 5 questions.
Match each characteristic to the correct bond type:
Using the pull-down menus, match each item in the left column to the
corresponding item in the right column.
1.1 Links partially charged
molecules
1.2 Links fully charged
molecules
1.3 Unequal sharing of an
electron pair
Ionic bond
Nonpolar covalent
bond
Hydrogen bond
Polar covalent bond
1.4 Equal sharing of an electron
pair
Match each property with the corresponding term:
Using the pull-down menus, match each item in the left column to the
corresponding item in the right column.
2.1 Means "does not associate well
with water"
2.2 Particles dispersed in a medium
Hydrophobic
Electrolyte
2.3 Medium in which particles are
dispersed
2.4 Means "interacts well with water"
Solvent
Hydrophilic
Solute
2.5 Dissolves to ions that conduct
current
Match each structural characteristic with the correct protein structure term:
Using the pull-down menus, match each item in the left column to the
corresponding item in the right column.
3.1 Glucose is an example of this
3.2 Formed when two simple sugars join
together
3.3 Glycogen and starch are examples of
this
3.4 Molecules that have the same types
and numbers of atoms, but different
structures-for example, glucose and
fructose
Polysaccharide
Isomers
Monosaccharide
Disaccharide
Match each term with the appropriate definition:
Using the pull-down menus, match each item in the left column to the
corresponding item in the right column.
4.1 Atom
4.2 Proton
4.3
Electron
Subatomic particle bearing a positive charge
Atoms with similar proton numbers but
different neutron numbers
Smallest stable units of matter
All atoms with the same number of protons
4.4
Element
Uncharged subatomic particle
Subatomic particle bearing a negative charge
4.5 Isotope
4.6
Neutron
Match each reaction with its proper type:
Using the pull-down menus, match each item in the left column to the
corresponding item in the right column.
5.1 This lipid is derived from arachidonic
acid
5.2 Cholesterol is an example of this lipid
Steroid
5.3 This lipid is an important energy
source, provides insulation, and protects
organs
Phospholipid
5.4 This lipid contains a phosphate group
linked to a diglyceride and a nonlipid group
5.5 This lipid can be saturated or
unsaturated
This activity contains 5 questions.
ATP is a carbohydrate.
True
False
Eicosanoid
Triglyceride
Fatty acid
A compound contains two or more elements.
True
False
A cation is an ion with a negative charge.
True
False
Protons are positively charged particles found in the atomic nucleus.
True
False
Kinetic energy is stored energy.
True
False
This activity contains 6 questions.
Ions that bear a positive charge are called
.
A fatty acid with no double bonds in its carbon chain is
.
A
is structurally related to the glycolipid and are important
in the maintenance of cell membranes.
A
is the bond between the carboxylic acid group of one amino
acid and the amino group of another.
Ions with a negative charge are called
.
A
protein is compact and generally rounded and readily enters
an aqueous solution.