Deck 2: Chemical Basis of Life

Question 1

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

Answer 1

True

Question 2

Steroid molecules consist of four connected rings of carbon atoms.

Answer 2

True

Question 3

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

Answer 3

True

Question 4

Matter is anything that has weight and takes up space.

Question 5

A covalent bond is formed when two atoms share electrons.

Question 6

The building blocks of triglyceride molecules are amino acids.

Question 7

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

Question 8

During an exchange reaction, the bonds of a reactant molecule break so that simpler molecules, atoms, or ions are formed.

Question 9

A synthesis reaction occurs when two or more atoms (reactants) bond to form a more complex structure (product).

Question 10

Cholesterol is a type of protein.

Question 11

A saltis a compound composed of oppositely charged ions.

Question 12

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

Question 13

A pH value indicatesthe hydrogen ion concentration in solutions such as body fluids.

Question 14

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

Question 15

Within a solution, buffers combine with hydrogen ions when H ⁺ ions are in excess or they donate hydroxide ions when H ⁺ ions are depleted.

Question 16

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

Question 17

Cells use oxygen to release energy from glucose.

Question 18

Water is an example of a compound.

Question 19

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

Question 20

A substance that dissociates and releases hydrogen ions into water is classified as a base.

Question 21

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

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

Question 22

Protons are the particles within an atom that determine the atom's bonding behavior.

Question 23

Based on their subatomic makeup, which atom is actually an ion?Atom 1: 3 protons, 2 neutrons, 3 electronsAtom 2: 3 protons, 3 neutrons, 2 electronsAtom 3: 3 protons, 1 neutron, 3 electrons

A) Atom 1
B) Atom 2
C) Atom 3

Question 24

Examples of proteins include DNA and RNA.

Question 25

What type of chemical bond is formed by the attraction of the positive hydrogen end of one polar molecule to the negative nitrogen or oxygen end of another polar molecule?

A) Ionic bond
B) Double bond
C) Triple bond
D) Hydrogen bond
E) Covalent bond

Question 26

What differs between the isotopes of a particular element?

A) The shape of the protons
B) The number of protons
C) The number of neutrons
D) The size of the electrons
E) The number of electron shells

Question 27

What is indicated by the formula H ₂O?

A) An atom that contains 2 hydrogen molecules and 1 oxygen molecule
B) An atom that contains 1 hydrogen atom and 2 oxygen molecules
C) A molecule that contains 2 hydrogen atoms and 1 oxygen atom
D) A molecule that contains 1 hydrogen atom and 2 oxygen atoms
E) A molecule that contains 2 hydrogen atomsand no oxygen atoms

Question 28

Ninety-five percent (95%) of the human body (by weight) is made up of what four elements?

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 29

The building blocks of proteins are molecules called amino acids.

Question 30

Indicate the substance that is NOT an element.

A) Iron
B) Oxygen
C) Water
D) Carbon
E) Hydrogen

Question 31

Atoms of different elements vary in size, weight, and ways they interact with other atoms.

Question 32

The __________ of an atom is determined by the electrons in its outermost shell.

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

Question 33

Carbon, oxygen, sodium, and hydrogen compose over 95% (by weight) of the human body.

Question 34

The first (innermost) electron shell of an atom can hold a maximum of __________ electrons.

A) 1
B) 2
C) 4
D) 8
E) 16

Question 35

Protons and electrons are similar in size.

Question 36

The electrons of an atom occupy one or more areas of space, called __________, around the nucleus.

A) pockets
B) shells
C) regions
D) zones
E) tracts

Question 37

The term __________ is defined as the amount of matter, while the term __________ refers to the gravitational pull on the matter.

A) mass; weight
B) weight; mass

Question 38

All isotopes of an element have the same number of electrons.

Question 39

By what mechanism does a chemical bond form between an ion of potassium (K+) and chloride (Cl-)?

A) Electrons are shared between ions, forming a bond.
B) The opposite charges of the ions cause them to be attracted to each other, forming a bond.
C) The protons of each nucleus are attracted to each other, forming a bond.
D) Neutrons from one ion are transferred to the other ion, forming a bond.

Question 40

As the concentration of hydrogen ions increases in a solution, the pH decreases.

Question 41

Consider the chemical reaction: H ₂SO ₄ → HSO ₄ ^- + H ⁺. In this reaction, is H ₂SO ₄ an acid or a base?

A) Acid
B) Base

Question 42

Water is the major __________ in the body.

A) solvent
B) solute

Question 43

Protons are located in the __________ of an atom and they have an electrical charge that is __________.

A) nucleus; negative
B) nucleus; neutral
C) shells; negative
D) nucleus; positive
E) shells; neutral

Question 44

As hydrogen ion concentration of a solution increases, what change occurs in the pH value?

A) The pH value increases.
B) The pH value decreases.
C) The pH value stays the same.
D) The pH becomes negative.
E) The pH value approaches 14.

Question 45

Inorganic substances called __________ dissociate in water, releasing ions.

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

Question 46

Indicate the inorganic substance.

A) Glucose
B) An enzyme
C) Cholesterol
D) Carbon dioxide
E) DNA

Question 47

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

A) pH of 0.6
B) pH of 2
C) pH of 5
D) pH of 7
E) pH of 8

Question 48

A solution with a pH of 4 is __________ and a solution with a pH of 9 is __________.

A) acidic; basic (alkaline)
B) acidic; neutral
C) basic (alkaline); acidic
D) basic (alkaline); neutral
E) neutral; acidic

Question 49

Neutrons are located in the __________ of an atom, and they have an electrical chargethat is __________.

A) nucleus; negative
B) nucleus; neutral
C) shells; negative
D) nucleus; positive
E) shells; neutral

Question 50

A(n) __________ solution contains more hydroxide ions than hydrogen ions.

A) basic
B) neutral
C) acidic

Question 51

Indicate the non-carbohydrate molecule.

A) Monosaccharide
B) Disaccharide
C) Protein
D) Polysaccharide
E) Glucose

Question 52

What type of chemicals function to resist changes in pH of a solution?

A) Buffers
B) Electrolytes
C) Acids
D) Bases
E) Ions

Question 53

What blood pH is associated with the condition called alkalosis?

A) Blood pH between 7.35 and 7.45
B) Blood pH below 7.0
C) Blood pH above 7.45
D) Blood pH below 7.35

Question 54

Indicate the compound that is an organic substance.

A) Water
B) Protein
C) Sodium chloride
D) Carbon dioxide
E) Oxygen

Question 55

How would a decomposition reaction be illustrated?

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

Question 56

Electrons are located in the __________ of an atom and they have an electrical charge that is __________.

A) nucleus; negative
B) nucleus; neutral
C) shells; negative
D) nucleus; positive
E) shells; neutral

Question 57

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

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

Question 58

Describe carbon dioxide.

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

Question 59

The branch of science called __________ deals with the composition of matter.

A) histology
B) chemistry
C) physiology
D) biology
E) cytology

Question 60

At the cellular level, physiology becomes the study of _________.

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

Question 61

Starch and glycogen are examples of what type of carbohydrate?

A) Monosaccharides
B) Polysaccharides
C) Disaccharides

Question 62

Ribose and deoxyribose are examples of what type of organic molecule?

A) Carbohydrates
B) Proteins
C) Lipids
D) Nucleic acids

Question 63

When atoms form bonds by sharing electrons, the bond formed is a(an) __________bond.

A) ionic
B) covalent
C) electronic
D) hydrogen

Question 64

C ₆H ₁₂O ₆ is an example of an __________ compound.

A) organic
B) inorganic

Question 65

What is the atomic number for an atom with 12 protons and 11 neutrons?

A) 11
B) 12
C) 23
D) 24

Question 66

Sucrose, lactose, and maltose are examples of what type of carbohydrate?

A) Monosaccharides
B) Polysaccharides
C) Disaccharides

Question 67

Atom X gains one electron, and Atom Y loses one. As a result, Atom X becomes __________ charged, Atom Y becomes __________ charged, and a(n) __________ bond can form.

A) negatively; positively; ionic
B) negatively; positively; polar covalent
C) positively; negatively; ionic
D) positively; negatively; polar covalent

Question 68

Overall, the electrical charge of a nucleus of an atom is always __________.

A) neutral
B) positive
C) negative

Question 69

An atom of oxygen has an atomic weight of 8. Its isotope with an atomic weight of 15 would have __________ neutrons in its nucleus.

A) 5
B) 7
C) 8
D) 15

Question 70

A __________ is a substance that dissolves in another substance, called the __________.

A) solute; solvent
B) solvent; solute

Question 71

What type of chemical bonds are, individually, relatively weak but, collectively, are strong enough to be responsible for the surface tension of water?

A) Ionic bonds
B) Polar covalent bonds
C) Hydrogen bonds
D) Nonpolar covalent bonds

Question 72

Galactose, glucose, and fructose are examples of what type of carbohydrate?

A) Monosaccharides
B) Polysaccharides
C) Disaccharides

Question 73

Atoms that lose or gain electrons become electrically charged particles called __________.

A) ions
B) molecules
C) protons
D) isotopes

Question 74

Three atoms have the following subatomic particles:Atom 1: 3 protons, 2 neutrons, 3 electronsAtom 2: 3 protons, 3 neutrons, 2 electronsAtom 3: 3 protons, 1 neutron, 3 electronsWhich statement best describes these three atoms?

A) They are all the same element; they are isotopes of each other.
B) They are three different elements; they are isotopes of each other.
C) They are all the same element; two of the atoms are ions.
D) They all have the same atomic number and atomic weight.

Question 75

Within a water molecule, the shared electrons forming the bonds between the hydrogen atoms and the oxygen atom spend more time at the oxygen end of the molecule than at the hydrogen end. These are examples of __________ bonds.

A) polar covalent
B) nonpolar covalent
C) ionic
D) hydrogen

Question 76

Addition of lactic acid to a solution will result in a(n) __________ in the pH of the solution.

A) increase
B) decrease

Question 77

What is the normal range for blood pH?

A) 6.35 - 7.45
B) 6.85 - 7.15
C) 7.0 - 7.35
D) 7.35 - 7.45

Question 78

Solution A has a pH of 6 and Solution B has a pH of 3. Which statement is correct?

A) Solution B has 3 times more H ⁺ than Solution A.
B) Solution B has 3 times less H ⁺ than Solution A.
C) Solution B has 30 times more H ⁺ than Solution A.
D) Solution B has 1000 times more H ⁺ than Solution A.
E) Solution B has 1000 times less H ⁺ than Solution A.

Question 79

Which atom will become a positively charged ion?

A) An atom that loses an electron
B) An atom that gains an electron
C) An atom that gains a neutron
D) An atom that loses a neutron

Question 80

What is the atomic weight for an atom with 12 protons and 11 neutrons?

A) 11
B) 12
C) 23
D) 24