A&P chem.
The formula for methane gas is CH4. What does the formula 4CH4 represent?
4 molecules, each containing a carbon atom and 4 hydrogen atoms
How many electrons can the second energy level hold when it is completely filled?
8
Which of the following is both an anion and a compound?
HCO3-
In sickle cell anemia, there is a replacement in the amino acid sequence of hemoglobin of glutamic acid by valine. What is the difference between glutamic acid and valine?
The R groups between the amino acids are different.
Ionic bonds, such as in sodium chloride, __________
are formed by the association of ions with opposite charges
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
The group of organic compounds containing carbon, hydrogen, and oxygen in a near 1:2:1 ratio is defined as a
carbohydrate
Each of the following is an inorganic compound except acids. carbohydrates. salts. bases. water.
carbohydrates
Glycoproteins and proteoglycans are combinations of amino acids and
carbohydrates
All fatty acids contain a functional group at one end called the ________ acid group.
carboxylic
Interaction between individual polypeptide chains to form a protein complex is ________ structure.
quaternary
To bond two monomers together, a molecule of water must be ________ to/from monomers. This process is called ________.
removed; dehydration synthesis
A fatty acid with no double bonds between carbon atoms is
saturated
The alpha-helix and beta sheet are examples of ________ protein structure.
secondary
The alpha-helix is an example of the __________ level of protein structure.
secondary
A shortage of steroids in the body would result in a shortage of
sex hormones and plasma membranes.
Which of the following substances would be most acidic?
stomach secretions, pH = 1
In a molecule of nitrogen, three pairs of electrons are shared by two nitrogen atoms. The type of bond that is formed is an example of a ________ bond.
triple covalent
The maximum number of electrons that the first energy level can hold is __________.
two
A peptide bond links __________.
two amino acids
You would expect a peptide bond to link
two amino acids.
Hydrophilic molecules readily associate with
water molecules
In hydrolysis reactions, compounds react with
water, causing decomposition
A polysaccharide that is formed in liver and muscle cells to store glucose is
glycogen.
According to the rules of complementary base pairing in nucleic acids, cytosine would pair with the base
guanine.
Helium (HE) has an atomic number of 2. It is chemically stable because it
has a full outer electron shell.
Which element commonly has only a proton as its nucleus?
hydrogen
The electrostatic attraction between the slight positive charge of a hydrogen of one molecule and the slight negative charge of an oxygen, nitrogen, or fluorine of another molecule is called a(n)
hydrogen bond.
Nonpolar organic molecules are good examples of
hydrophobic compounds
Molecules that do not readily interact with water are called
hydrophobic.
Molecules that have the same molecular formula but different structural formulas are called
isomers.
In dehydration synthesis reactions, compounds
lose water molecules
Each amino acid differs from another in the
nature of the side chain.
A solution containing equal numbers of hydrogen ions and hydroxide ions is
neutral.
Isotopes of an element differ in the number of
neutrons in the nucleus.
Oxygen, which forms naturally as two atoms, are bonded together with what type of bond?
nonpolar covalent bond
Molecules that store and process genetic information are the
nucleic acids.
An amino acid is to a protein as a ________ is to a nucleic acid.
nucleotide
The chemical properties of an atom are determined by the __________.
number of electrons in the outermost electron shell
Compounds that contain carbon as the primary structural atom are called ________ molecules.
organic
Carbohydrates, lipids, and proteins are classified as
organic molecules.
By weight, which element is the most plentiful in the human body?
oxygen
Which pH is closest to normal body pH?
pH of 7
Molecules with two fatty acid chains and a phosphate group that form biological membranes are called
phospholipids
If a pair of electrons is unequally shared between two atoms, a(n) ________ bond occurs.
polar covalent
What type of chemical bond holds the atoms in a water molecule together?
polar covalent bond
Water molecules are formed by __________.
polar covalent bonds
A fatty acid that contains two or more double covalent bonds is said to be
polyunsaturated.
The "atomic number" of an atom is determined by the number of ________ it has.
protons
The "atomic weight" of an atom reflects the average number of
protons + neutrons
The nucleus of an atom consists of
protons + neutrons.
Adenine and guanine are
purines represented by A and G.
Oxygen (atomic number 8) requires how many additional electrons to fill its outer electron shell?
2
Which of the following is/are needed to form a triglyceride molecule?
3 fatty acid molecules and 1 glycerol molecule
Which of the following has the highest concentration of hydroxide ions?
PH 14
Many lipids are composed of fatty acids and
glycerol
If 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 magnesium to form ions with a charge of
+2
Which of the following functional groups is the carboxyl group?
-COOH
Which of the following is the symbol for an amino group?
-NH2
Which of the following functional groups is the hydroxyl group?
-OH
Which of the following functional groups is the phosphate group?
-PO4
Lipids
-provide a significant energy reserve. -form essential structural components of cells. -help to maintain body temperature. -cushion organs against shocks.
Sodium (NA) has an atomic number of 11. How many electrons are in the outer electron shell of a neutral sodium atom
1
What structural differences make adenine and guanine different from cytosine, thymine, and uracil?
Adenine and guanine are double-ringed nitrogenous bases, while cytosine, thymine, and uracil are single-ringed.
________ is a type of indigestible polysaccharide.
Cellulose
Which of the following statements about water is false?
It has a relatively low heat capacity.
Which of these is NOT a property of glucose?
It is a disaccharide.
Wheat produces starch and cellulose, both of which are polysaccharides. While we rely on one for energy, we cannot digest the other. What causes such a physiological difference in digestion?
It is the ability of our bodies to break down the linkages between the multiple glucose molecules.
Identify the correct statement regarding the process of denaturation.
It is the loss of protein structure.
In chemical notation, the symbol Ca2+ means
a calcium ion that has lost two electrons
When two monosaccharides undergo a dehydration synthesis,
a disaccharide is formed.
Fructose is
a hexose. an isomer of glucose. a carbohydrate. found in male reproductive fluids. All of the answers are correct.
Substrate molecules bind to enzymes at the ________ sites.
active
The purines found in DNA are ________ and guanine.
adenine
If a substance has a pH that is greater than 7, it is
alkaline.
The monomers of protein are
amino acids.
A side chain on an amino acid is sometimes called
an R group.
In an aqueous solution, cations are attracted toward
anions
What type of bond does an unsaturated fatty acid contain that a saturated fatty acid does not?
at least one double covalent bond
The smallest stable units of matter are
atoms
Hydrogen bonds do not form between two hydrogen atoms. Where do hydrogen bonds form
between the slight positive charge on the hydrogen atom and the slight negative charge on the oxygen atom
In an ionic bond, the electron donor is the ________, whereas the electron acceptor is the _______
cation; anion
H2O is an example of a(n)
compound
When atoms complete their outer electron shell by sharing electrons, they form
covalent bonds
The molecule DNA contains a five-carbon sugar called
deoxyribose.
An excess of hydrogen ions in the body fluids can have fatal results because this can
disrupt tissue functions. change the shape of proteins, rendering them nonfunctional. change body fluid pH. break chemical bonds. All of the answers are correct.
During ionization, water molecules disrupt the ionic bonds of a salt to produce a mixture of ions. These ions can carry a current and so are called
electrolytes
Electrons whirl around the center of the atom at high speed, forming a(n)
electron cloud.
A(n) ________ is a pure substance composed of atoms of only one kind.
element
Electrons in an atom occupy an orderly series of electron shells or
energy level
A nucleotide consists of a
five-carbon sugar, a nitrogenous base, and a phosphate group.
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.
Cholesterol, phospholipids, and glycolipids are examples of
structural lipids.
Consider sweetened ice tea. Which of the following is a solute?
sugar
AB → A + B is to decomposition as A + B → AB is to
synthesis.
The structure of RNA differs from DNA in that
the backbone of RNA contains ribose.
What makes fatty acid 3 an unsaturated fatty acid?
the presence of a double covalent bond
