Deck 2: Chemical Basis of Life

Question 1

Matter is anything that has weight and takes up space.

Answer 1

True

Question 2

At present,there are 90 known naturally occurring ________.

Answer 2

elements

Question 3

The atomic ________ of an atom of an element equals the number of protons and neutrons in its nucleus.

Answer 3

weight

Question 4

An element with an atomic number of 6 contains 12 protons.

Question 5

Understanding ________ is essential for understanding anatomy and physiology because body structures and functions result from chemical changes.

Question 6

Which elements make up 95% (by weight)of the human body?

A) carbon,hydrogen,oxygen,nitrogen
B) carbon,hydrogen,oxygen,calcium
C) carbon,hydrogen,calcium,nitrogen
D) carbon,hydrogen,selenium,sodium
E) sodium,calcium,nitrogen,selenium

Question 7

When atoms combine with other atoms,interactions occur between their ________ shells.

Question 8

Which of the following substances is NOT an element?

A) iron
B) oxygen
C) water
D) carbon
E) hydrogen

Question 9

The atoms of the isotopes of a particular element vary in the number of

A) electrons.
B) protons.
C) neutrons.
D) nuclei.
E) electron shells.

Question 10

The parts of an atom that lack an electrical charge are called ________.

Question 11

Chemistry is the branch of science that deals with the composition of matter.

Question 12

Which of the following is the number of elements living organisms require?

A) 10
B) 15
C) 20
D) 90
E) 144

Question 13

Each element is composed of characteristic tiny particles called ________.

Question 14

All of the food that we eat,liquids that we drink and medications that we take are

A) chemicals.
B) vitamins.
C) proteins.
D) nucleic acids.
E) carbohydrates.

Question 15

The atomic weight of an atom of an element equals the number of neutrons in its nucleus.

Question 16

All matter is composed of atoms of fundamental substances called ________.

Question 17

The number of protons in the atoms of a particular element is called the element's atomic ________.

Question 18

________ is defined as anything that has weight and takes up space.

Question 19

The electrons of an atom occupy one or more areas of space called

A) bonds.
B) shells.
C) regions.
D) ions.
E) nuclei.

Question 20

The electrons in the outermost shell of an atom determine its

A) shape.
B) weight.
C) chemical behavior.
D) mass.
E) atomic number.

Question 21

The molecular formula for compounds like sodium chloride (NaCl)give the relative amounts of each element present.

Question 22

A covalent bond is formed by two atoms that share electrons.

Question 23

Sodium and chloride ions readily combine because they have opposite charges.

Question 24

The type of chemical bond formed when atoms share electrons is called ________.

Question 25

A ________ reaction is symbolized as A+B→AB.

Question 26

A molecule of a compound always contains definite kinds and numbers of atoms.

Question 27

The formula H₂O means

A) an atom contains 2 hydrogen molecules and 1 oxygen molecule.
B) an atom contains 1 hydrogen atom and 2 oxygen molecules.
C) a molecule contains 2 hydrogen atoms and 1 oxygen atom.
D) a molecule contains 1 hydrogen atom and 2 oxygen atoms.
E) a molecule contains 2 hydrogen atoms and no oxygen atoms.

Question 28

If the bonds of a reactant molecule break so that simpler molecules,atoms or ions form,the reaction is an exchange reaction.

Question 29

When two or more atoms bond,they form a new kind of particle called a molecule.

Question 30

A ________ reaction is symbolized as AB→A+B.

Question 31

A molecular formula represents the numbers and types of atoms in a molecule.

Question 32

The first electron shell of an atom can hold a maximum of

A) 1 electron.
B) 2 electrons.
C) 4 electrons.
D) 8 electrons.
E) 16 electrons.

Question 33

When atoms of different elements bond,they form molecules called ________.

Question 34

The attraction of the positive hydrogen end of a polar molecule to the negative nitrogen or oxygen end of another polar molecule is called a(an)

A) ionic bond.
B) double bond.
C) triple bond.
D) hydrogen bond.
E) covalent bond.

Question 35

An atom that has gained or lost electrons is called an ion.

Question 36

Atoms that gain or lose electrons become electrically charged and are called ________.

Question 37

A ________ formula shows how atoms are joined and arranged in various molecules.

Question 38

The type of chemical bond formed when ions with opposite electrical charges are attracted to one another is called ________.

Question 39

Water is an example of a compound.

Question 40

If two pairs of electrons are shared,the resulting bond is called a double covalent bond.

Question 41

A person has alkalosis if the blood pH

A) rises above 7.0.
B) drops below 7.0.
C) rises above 7.4.
D) drops below 7.4.
E) steadily decreases.

Question 42

A decomposition reaction can be symbolized as ________.

A) A+B→C+D
B) A+B→AB
C) AB→A+B
D) C+D→AB
E) AB + CD → AC + BD

Question 43

An acid is defined as an electrolyte that releases hydroxide ions (OH^-)in water.

Question 44

When two or more atoms (reactants)bond to form a more complex structure (product)the reaction is called synthesis.

Question 45

An ________ is defined as a substance that ionizes in water.

Question 46

A solution that has a pH of 6 has ten times the hydrogen ion concentration of a solution with a pH of

A) 7.
B) 5.
C) 8.
D) 2.
E) 0.6.

Question 47

A substance that releases hydrogen ions in water is a base.

Question 48

A chemical reaction in which pairs of two different molecules trade positions is called a(an)________ reaction.

A) decomposition
B) exchange
C) reversible
D) synthesis
E) irreversible

Question 49

The opposite of a decomposition reaction is called a ________ reaction.

Question 50

Chemicals that resist changes in pH are called

A) buffers.
B) electrolytes.
C) acids.
D) bases.
E) none of the above.

Question 51

Which term describes a solution that contains more hydroxide ions than hydrogen ions?

A) basic
B) neutral
C) low pH
D) acidic
E) None of the above

Question 52

As a group,compounds that release ions when they dissolve in water are called

A) acids.
B) bases.
C) salts.
D) electrolytes.
E) solvents.

Question 53

A solution that contains more hydrogen ions than hydroxide ions is _________.

Question 54

Buffers combine with hydrogen ions when H⁺ is in excess or they donate hydroxide ions when H⁺ is depleted.

Question 55

The pH scale ranges from 0 to 14.

Question 56

pH is a measure of _________ ion concentration.

Question 57

A pH value indicates the hydrogen ion concentration in solutions,including body fluids.

Question 58

As hydrogen ion concentration increases,the pH number

A) gets.
B) gets smaller.
C) stays the same.
D) becomes negative.
E) approaches 14.

Question 59

________ are chemicals that resist changes in pH.

Question 60

Each whole number on the pH scale represents a ________ - fold difference in hydrogen ion concentration.

A) 15
B) 100
C) 20
D) 10
E) 2

Question 61

Proteins include DNA and RNA.

Question 62

A salt is a compound composed of oppositely charged ions.

Question 63

Many inorganic substances dissociate in water to release ions.

Question 64

At the cellular level of organization,biology becomes the study of

A) organs.
B) chemistry.
C) tissues.
D) organ systems.
E) human populations.

Question 65

The different types of carbohydrates do NOT include

A) monosaccharides.
B) disaccharides.
C) proteins.
D) polysaccharides.
E) glucose.

Question 66

Which of the following is NOT organic?

A) A carbohydrate
B) A protein
C) A lipid
D) Carbon dioxide
E) A nucleic acid

Question 67

Inorganic substances that usually dissociate in water are called

A) organic compounds.
B) non-electrolytes.
C) electrolytes.
D) lipids.
E) carbohydrates.

Question 68

Organic substances always contain the elements hydrogen and ________.

Question 69

Steroid molecules have four connected rings of carbon atoms.

Question 70

Water accounts for 2/3 of the weight of an adult human.

Question 71

The building blocks of fat molecules are amino acids.

Question 72

Which of the following chemicals is NOT an inorganic substance?

A) water
B) protein
C) sodium chloride
D) carbon dioxide
E) oxygen

Question 73

________ are the building blocks of nucleic acids.

Question 74

Carbon dioxide is

A) inhaled in large quantities from the environment.
B) a waste product of metabolic processes.
C) an element.
D) a salt.
E) an electrolyte.

Question 75

Certain cellular organelles use oxygen to release energy from glucose.

Question 76

________ is the most abundant compound in living material.

Question 77

Neutrons are located in the _________ of an atom and they have a "charge" that is ________.

A) nucleus,negative
B) nucleus,neutral
C) shells,negative
D) nucleus,positive

Question 78

Cholesterol is a protein.

Question 79

________ are lipids used primarily to store energy for cellular activities.

Question 80

The building blocks of proteins are amino acids.