Chapter 2 Flashcards
Solutions with a pH value less than 7 are known as _________ in nature.
Acidic
Solutions are said to be _________ when the pH value is greater than 7.
basic
PH Basic
Above 7
Solutions are _________ when the pH value is 7.
neutral
The smallest particle of an element that maintains the chemical properties of the element.
Atom
An electrically charged atom; has unequal numbers of electrons and protons.
Ion
A chemical particle composed of two or more atoms united by a covalent chemical bond.
molecule
The study of the composition, structure, and reactions of matter.
chemistry
The power to cause something to move; to work.
energy
Anything that occupies space and has mass.
matter
The simplest type of matter composed of atoms of only one kind that maintains unique chemical properties.
element
Substance that releases protons; proton donor.
Acid
Substance that accepts protons; proton acceptor.
base
A shorthand system to track hydrogen ion concentration is substances; categorizes the acidity levels of substances.
PH scale
A simple sugar organic substance with a 2:1 ratio of hydrogen to oxygen.
carbohydrate
An organic substance composed of carbon, oxygen, and hydrogen.
lipid
An atom has an atomic number of 19 and a mass number of 39. This atom will have
Select one:
a. 19 neutrons.
b. 20 neutrons.
c. 39 neutrons.
d. 58 neutrons.
e. 20 electrons.
b. 20 neutrons.
The molecular formula H2O means
Select one:
a. 1 hydrogen atom and 2 oxygen atoms.
b. 1 hydrogen atom and 1 oxygen atom.
c. 2 hydrogen atoms and 1 oxygen atom.
d. 2 hydrogen atoms and 2 oxygen atoms.
e. None of these choices is correct.
c. 2 hydrogen atoms and 1 oxygen atom.
Hydrogen bonds are important for all of the following except:
Select one:
a. producing surface tension in water
b. helping hold a protein structure together
c. helping hold DNA strands together
d. helping atoms give up or receive electrons
d. helping atoms give up or receive electrons
The three forms of matter are:
Select one:
a. air, water, and solids.
b. solids, liquids, and gases.
c. blood, bone, and air.
d. vapor, water, and solid.
b. solids, liquids, and gases.
Kinetic energy is
Select one:
a. the form of energy that actually does work.
b. movement of ions or electrons.
c. energy that flows between objects with different temperatures.
d. stored energy that could do work but is not doing so.
e. energy that moves in waves.
a. the form of energy that actually does work.
Which of the following pairs is mismatched?
Select one:
a. synthesis reaction - two reactants combine to form a larger product
b. decomposition reaction - large reactant broken into smaller products
c. oxidation - gain of electrons
d. dehydration reaction - water is a product of the reaction
e. hydrolysis - water is used in decomposition reaction
c. oxidation - gain of electrons
Molecules that form when electrons are shared unequally between atoms are called
Select one:
a. salt molecules.
b. polar molecules.
c. nonpolar molecules.
d. lopsided molecules.
e. None of these choices are correct.
b. polar molecules.
Sucrose is formed when the simple sugars fructose and glucose are covalently bonded. This reaction releases water. What type of reaction is this?
Select one:
a. catabolic
b. hydrolysis
c. dehydration
d. monomeric
c. dehydration
A neutral atom will become a cation if it
Select one:
a. gains electrons.
b. gains protons.
c. loses electrons.
d. loses protons.
e. gains neutrons.
c. loses electrons.
Chemical substances that dissolve in water or react with water to release ions are known as
Select one:
a. buffers.
b. enzymes.
c. bases.
d. inorganic compounds.
e. electrolytes.
e. electrolytes.
Why are cyanide compounds lethal to humans?
Select one:
a. They interfere with protein synthesis.
b. They interfere with nerve impulses.
c. They interfere with the production of ATP.
d. They interfere with muscle contraction.
e. All of these occur with cyanide poisoning.
c. They interfere with the production of ATP.
Normal pH for blood is 7.35 to 7.45. Maintenance of the pH in this range is
Select one:
a. critical because enzymes work best within narrow ranges of pH.
b. not critical because extreme pH values do not affect enzyme function.
c. called denaturation.
d. not required.
e. None of these choices is correct.
a. critical because enzymes work best within narrow ranges of pH.
Proteins
Select one:
a. are the body’s source of immediate energy.
b. are the building blocks of nucleotides.
c. provide much of the structure of body cells and tissues.
d. contain the genetic information of the cell.
e. insulate and cushion the body.
c. provide much of the structure of body cells and tissues.
A
Salt crystal
B
Sodium Ion
C
Chloride Ion
D
Water Ions
A
Polar (hydrophilic) region (phosphate containing region)
B
Nonpolar (hydrophobic) region (fatty acids)
C
Nitrogren
D
Phosphorous
E
Oxygen
DNA
Select one:
a. must travel to ribosomes to function.
b. contains the sugar deoxyribose.
c. is a single-stranded molecule.
d. is one of several amino acids.
e. assembles amino acids to make proteins..
b. contains the sugar deoxyribose.
Which of the following is determined by sequence of amino acids bound by peptide bonds?
Select one:
a. amino acid
b. peptide bond
c. primary structure of protein
d. secondary structure of protein
e. denaturation
c. primary structure of protein
Phospholipids have a hydrophilic end which is
Select one:
a. polar and water-insoluble.
b. polar and water-soluble.
c. nonpolar and water -insoluble.
d. nonpolar and water-soluble.
b. polar and water-soluble.
A
water molecule
B
hydrogen bond
C
hydrogen atom
D
oxygen atom
E
hydrogen bond
The smallest particle of an element that still has the chemical characteristics of that element is a(n)
electron.
molecule.
neutron.
proton.
atom.
atom
12C and 14C are
atoms of different elements.
isotopes.
atoms with different atomic numbers.
atoms with different numbers of protons.
compounds.
isotopes.
A cation is a(n)
uncharged atom.
positively charged atom.
negatively charged atom.
atom that has gained an electron.
positively charged atom.
A polar covalent bond between two atoms occurs when
one atom attracts shared electrons more strongly than another atom.
atoms attract electrons equally.
an electron from one atom is completely transferred to another atom.
the molecule becomes ionized.
a hydrogen atom is shared between two different atoms.
one atom attracts shared electrons more strongly than another atom.
Table salt (NaCl) is
an atom.
organic.
a molecule.
a compound.
a cation.
a compound.
The weak attractive force between two water molecules forms a(n)
covalent bond.
hydrogen bond.
ionic bond.
compound.
isotope.
hydrogen bond.
Electrolytes are
nonpolar molecules.
covalent compounds.
substances that usually don’t dissolve in water.
found in solutions that do not conduct electricity.
cations and anions that dissociate in water.
cations and anions that dissociate in water.
In a decomposition reaction,
anabolism occurs.
proteins are formed from amino acids.
large molecules are broken down to form small molecules.
a dehydration reaction may occur.
All of these are correct.
large molecules are broken down to form small molecules.
Oxidation-reduction reactions
can be synthesis or decomposition reactions.
have one reactant gaining electrons.
have one reactant losing electrons.
can create ionic or covalent bonds.
All of these are correct.
All of these are correct.
Potential energy
is energy caused by movement of an object.
is the form of energy that is actually doing work.
includes energy within chemical bonds.
can never be converted to kinetic energy.
All of these are correct.
includes energy within chemical bonds.
Which of these descriptions of heat energy is not correct?
Heat energy flows between objects that are at different temperatures.
Heat energy can be produced from all other forms of energy.
Heat energy can be released during chemical reactions.
Heat energy must be added to break apart ATP molecules.
Heat energy is always transferred from a hotter object to a cooler object.
Heat energy must be added to break apart ATP molecules.
Which of these statements concerning enzymes is correct?
Enzymes increase the rate of reactions but are permanently changed as a result.
Enzymes are proteins that function as catalysts.
Enzymes increase the activation energy requirement for a reaction to occur.
Enzymes usually can only double the rate of a chemical reaction.
Enzymes increase the kinetic energy of the reactants.
Enzymes are proteins that function as catalysts.
Water
is composed of two oxygen atoms and one hydrogen atom.
has a low specific heat.
is composed of polar molecules into which ionic substances dissociate.
is produced in a hydrolysis reaction.
is a very small organic molecule.
is composed of polar molecules into which ionic substances dissociate.
When sugar is dissolved in water, the water is called the
solute.
solution.
solvent.
solvent.
Which of these is an example of a suspension?
sweat
water and proteins inside cells
sugar dissolved in water
red blood cells in plasma
red blood cells in plasma
A solution with a pH of 5 is _____ and contains _______ H+ than (as) a neutral solution.
a base, more
a base, fewer
an acid, more
an acid, fewer
neutral, the same number of
an acid, more
A buffer
slows down chemical reactions.
speeds up chemical reactions.
increases the pH of a solution.
maintains a relatively constant pH.
works by forming salts.
maintains a relatively constant pH.
A conjugate acid-base pair
acts as a buffer.
can combine with H+ in a solution.
can release H+ to combine with OH−.
describes carbonic acid (H2CO3) and bicarbonate ions (HCO3−).
All of these are correct.
All of these are correct.
The polysaccharide used for energy storage in the human body is
cellulose.
glycogen.
lactose.
sucrose.
starch.
glycogen.
The basic units or building blocks of triglycerides are
simple sugars (monosaccharides).
double sugars (disaccharides).
amino acids.
glycerol and fatty acids.
nucleotides.
glycerol and fatty acids.
A ______ fatty acid has one double covalent bond between carbon atoms.
cholesterol
monounsaturated
phospholipid
polyunsaturated
saturated
monounsaturated
The _______ structure of a protein results from the folding of the pleated sheets or helices.
primary
secondary
tertiary
quaternary
tertiary
According to the lock-and-key model of enzyme action,
reactants must first be heated.
enzyme shape is not important.
each enzyme can catalyze many types of reactions.
reactants must bind to an active site on the enzyme.
enzymes control only a small number of reactions in the cell.
reactants must bind to an active site on the enzyme.
DNA molecules
contain genes.
contain a single strand of nucleotides.
contain the nucleotide uracil.
are of three different types that have roles in protein synthesis.
contain up to 100 nitrogenous bases.
contain genes.
ATP
is formed by the addition of a phosphate group to ADP.
is formed with energy released during catabolic reactions.
provides the energy for anabolic reactions.
contains three phosphate groups.
All of these are correct.
All of these are correct.
primary structure of protein
sequence and shape = function
secondary structure
fold and bending caused by pleat or helix
tertiary structure
large scale folding, shape of folded sequence
quaternary structure of protein
2+ proteins form functional unit
