Anatomy and Physiology Chapter 2-Chemical Level of Organization
In the reaction listed below, what coefficient needs to be added to balance the equation? 6 CO2 +6 H2O --- C6H12O6 + ___ O2
6
If an element is composed of atoms with an atomic number of 6 and a mass number of 14, then the nucleus of a neutral atom of this element contains
6 protons and 8 neutrons
Which of the following is both an anion and a compound
HCO3-
In an aqueous solution, sodium ions would move toward
a negative terminal
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 gas, two pairs of electrons are 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 elements?
silicon, flourine, tin
If one pair of electrons is unequally shared between two atoms, a _______ _____ _________ _____ occurs
single polar covalent bond
A ________ is a homogeneous mixture containing a solvent and a solute.
solution
Hydrophilic molecules readily associate with
water molecules
In hydrolysis reactions, compounds react with
water, causing decomposition
Oppositely charged ions in solution are prevented from combining by
hydration spheres
The molecule H2 is known as
hydrogen
The weakest bond between two atoms is the _______ bond.
hydrogen
Which element commonly has only a proton as its nucleus?
hydrogen
Molecules that do no readily dissolve in water are called
hydrophobic
Nonpolar organic molecules are good examples of
hydrophobic compounds
Molecules that have the same molecular formula but different structural formulas are called
isomers
Atoms of the same element whose nuclei contain the same number of protons, but different number of neutrons, are called
isotopes
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
molecular formula
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
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
By weight, which element is the most plentiful in the human body
oxygen
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 pH
pH 7
A fatty acid that contains multiple double covalent bonds is said to be
polyunsaturated
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 _______ it has.
protons
The mass number represents the number of
protons + neutrons
The mass of an atom is largely determined by the number of
protons + neutrons
The atomic weight of an atom reflects the average number of
protons + neutrons + electrons
The nucleus of an atom consists of
protons and neutrons
The innermost electron shell in an atom holds up to
2 electrons
Of the following choices, the pH of the least acidic solution is
12.0
A polysaccharide that is formed in muscle cells to store glucose is
glycogen
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 is the symbol for an amino group?
-NH2
Which of the following are needed to form a triglyceride molecule?
1 glycerol +3 fatty acid molecules
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
Lipids
All of the answers are correct A.form essential structural components of cells B.provide roughly twice the energy as carbohydrates C.help maintain body temperature D.cushion organs against shock
An excess of hydrogen ions in the body fluids can have fatal results because this can
All of the answers are correct: A. block ion movements B. change the shape of large complex molecules, rendering them nonfunctional C. Disrupt tissue functions
____________ are soluble inorganic compounds whose solutions will conduct an electric current.
Electrolytes
_______ accelerate chemical reactions that occur in the human body.
Enzymes
Which of the following statements about hydrogen bonds is false?
Hydrogen bonds are strong attractive forces between hydrogen atoms and negatively charged atoms
_________ compounds do not usually contain carbon as a primary structural atom.
Inorganic
Which of the following statements about water is not correct?
It has a relatively low heat capacity
When a small amount of HCI or NaOH is added to a solution of Na2HPO4, the pH of the solution barely changes. Based on these observations, all of the following are true concerning the compound Na2HPO4 except
Na2HPO4 adsorbs excess H+ and OH- directly onto the surface of its crystalline structure
An important buffer in body fluids is
NaHCO3
_______ molecules are compounds that contain carbon as the primary structural atom.
Organic
In chemical notation, the symbol Ca2+
a calcium ion that has lost two electrons
When two monosaccharides undergo a dehydration synthesis,
a disaccharide is formed
In living cells, complex metabolic reactions proceed in a series of steps called
a metabolic pathway
If a substance has a pH that is great than 7, it is
alkaline
Fructose
all of the above are correct A. is a hexose B. is an isomer of glucose C. is found in fruits
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
Ions with a negative charge are called
anions
Which of the following is not a cation
anything with a negative charge
All of the following are true concerning enzymes except that they
are consumed during the reaction
The actual mass of an atom is known as its
atomic weight
The smallest stable units of matter are
atoms
A functional group is best described as reoccurring clusters of
atoms that greatly influence the chemical properties of molecules they are part of
A ____ removes hydrogen ions, and a ____ releases hydrogen ions.
base;acid
Which of the following are inorganic substances?
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 1:2:1 ratio is defined as
carbohydrate
Ions with a + charge are called
cations
Oxygen is required in biological systems for
cellular respiration
When atoms complete their outer electron shell by sharing electrons, they form
covalent bonds
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
Ionic bonds are formed when
electrons are completely transferred from one atom to another
A _______ 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
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
Which of the following substances would be most acidic
stomach secretions, pH=1
When placed in water, an inorganic compound dissociates 99 percent, forming hydrogen ions and anions. This compound would be a
strong acid
An example of an organic substance is
sucrose
A dust particle floating on a water surface illustrates
surface tension
AB---A + B is to decomposition as A + B ---AB is to
synthesis
The reaction N2 +3 H2 ---2 NH3 is an example of a
synthesis reaction
Which property of water helps keep body temperature stabilized?
thermal inertia
Lipids made of a glycerol molecule with two fatty acids attached to one side and a phosphate group connecting a nonlipid group attached to the other are
triglycerides
