Deck 2: The Chemical Level of Organization

Question 1

Combinations of atoms that contain different elements are called

A) molecules.
B) compounds.
C) mixtures.
D) isotopes.
E) none of the above

Answer 1

B

Question 2

If an element is composed of atoms with an atomic number of 8 and a mass number of 14, then a neutral atom of this element contains

A) 6 protons.
B) 6 neutrons.
C) 6 electrons.
D) 14 protons.
E) 14 electrons.

Answer 2

B

Question 3

The uncharged subatomic particles are

A) atoms.
B) molecules.
C) protons.
D) neutrons.
E) electrons.

Answer 3

D

Question 4

Which of the following would have a negative charge?

A) an atom
B) a molecule
C) a proton
D) a neutron
E) an electron

Question 5

Matter containing two atoms of the same element bonded together would be called

A) molecules.
B) cells.
C) compounds.
D) elements.
E) none of the above

Question 6

How many electrons do MOST atoms need in their outer shell to be stable?

A) two
B) three
C) four
D) six
E) eight

Question 7

The identity of an atom is determined by the

A) number of protons.
B) number of neutrons.
C) number and arrangement of electrons.
D) size of the atom.
E) mass of the atom.

Question 8

Covalent bonds are formed when

A) atoms share electrons.
B) cations and anions are held together by their opposite charges.
C) a pair of electrons is shared unequally by two atoms.
D) hydrogen forms bonds with negatively charged atoms in the same or different molecules.
E) two or more atoms lose electrons at the same time.

Question 9

In a molecule of oxygen, two pairs of electrons are shared equally; such a bond is called a

A) hydrogen covalent bond.
B) polar covalent bond.
C) nonpolar covalent bond.
D) oxygen covalent bond.
E) hydrogen bond.

Question 10

Which of the following is a weak electrical attraction between molecules?

A) ionic bond
B) covalent bond
C) polar bond
D) metallic bond
E) hydrogen bond

Question 11

Positively charged subatomic particles are called

A) protons.
B) neutrons.
C) electrons.
D) quarks.
E) radioactivity.

Question 12

The mass number represents the number of

A) protons in an atom.
B) electrons in an ion.
C) neutrons in an atom.
D) protons and neutrons.
E) neutrons and electrons.

Question 13

Atoms of the same element but containing different numbers of neutrons are called

A) isomers.
B) cations.
C) isotopes.
D) anions.
E) none of the above

Question 14

Which of the following is the most abundant element in the human body?

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

Question 15

Which of the following is sometimes used in diagnostic imaging?

A) a radioisotope.
B) a proton.
C) an ion.
D) an atom.
E) a gamma ray.

Question 16

The branch of science that deals with changes in molecules is

A) biology.
B) pathology.
C) botany.
D) geology.
E) chemistry.

Question 17

When electrons are shared between one atom and another and the two atoms unite as a result of the electron sharing,

A) an ion is formed.
B) a molecule is formed.
C) a hydrogen bond is formed.
D) an ionic bond is formed.
E) a covalent bond is formed.

Question 18

Which of the following is a characteristic of hydrogen bonds?

A) Hydrogen bonds are strong attractive forces between hydrogen atoms and negatively charged atoms.
B) Hydrogen bonds occur ONLY in water.
C) Hydrogen bonds can form between neighboring molecules.
D) Hydrogen bonds are part of fatty-acid structure.
E) Hydrogen bonds are part of carbohydrate structure.

Question 19

Ions with a negative charge are called

A) cations.
B) anions.
C) radicals.
D) polyatomic ions.
E) none of the above

Question 20

If two pairs of electrons are shared between two atoms, what type of bond occurs?

A) single covalent bond
B) double covalent bond
C) triple covalent bond
D) polar covalent bond
E) hydrogen bond

Question 21

In an endergonic reaction,

A) large molecules are broken down into smaller ones.
B) small molecules are assembled into larger ones.
C) molecules are rearranged to form new molecules.
D) molecules move from reactants to products and back.
E) energy is consumed during the reaction.

Question 22

Which of the following substances would be nearest the pH of human blood?

A) lemon juice, pH = 5.5
B) urine, pH = 6
C) tomato juice, pH = 4
D) white wine, pH = 3
E) stomach secretions, pH = 2

Question 23

Which of the following is an example of a strong base?

A) NaCl
B) NaOH
C) HCl
D) KF
E) H₂O

Question 24

It is important to keep pH regulated because an imbalance in H⁺ concentration can cause

A) unwanted chemical reactions.
B) overactivation of enzymes.
C) deactivation of enzymes.
D) structural damage.
E) all of the above

Question 25

A solution containing more hydrogen ions than hydroxide ions is

A) acidic.
B) basic.
C) neutral.
D) alkaline.
E) none of the above

Question 26

A decomposition reaction of a triglyceride could yield

A) a steroid.
B) a hormone.
C) monoglyceride and a fatty acid.
D) a diglyceride and two fatty acids.
E) glycerol and three fatty acids.

Question 27

Chlorine atoms have seven electrons in the outermost shell. As a result, one would expect chlorine to form ions with a charge of

A) +1.
B) +2.
C) -1.
D) -2.
E) none of the above

Question 28

AB → A + B is to decomposition as A + B ↔ AB is to

A) exchange.
B) reversible.
C) combustion.
D) replacement.
E) metabolism.

Question 29

Which of the following is the most abundant chemical compound in the human body?

A) water
B) acids
C) bases
D) salts
E) organic molecules

Question 30

If a substance resists changes in pH, it is called

A) neutral.
B) acidic.
C) alkaline.
D) a buffer.
E) a salt.

Question 31

The reaction N₂ + 3H₂ → 2NH₃ would be an example of a(n)

A) exchange reaction.
B) decomposition reaction.
C) synthesis reaction.
D) enzyme reaction.
E) metabolic reaction.

Question 32

All of the elements and compounds that are eaten and used by the body for some function are called

A) inorganic compounds.
B) organic compounds.
C) nutrients.
D) metabolites.
E) enzymes.

Question 33

Which statement about the reaction H₂ + Cl₂ → 2HCl is correct?

A) H₂ and Cl₂ are the products.
B) HCl is the product.
C) One molecule of hydrogen contains one atom.
D) One molecule of chlorine contains one atom.
E) All of the above are correct.

Question 34

The addition of energy to start a reaction is called the energy of

A) endergonic control.
B) activation.
C) exergonic control.
D) release.
E) none of the above

Question 35

Inorganic acids in the body include

A) hydrochloric
B) carbonic
C) sulfuric
D) phosphoric
E) all of the above

Question 36

When placed in water, an inorganic compound dissociates 99 percent, forming hydrogen ions and anions. This substance would be a

A) strong base.
B) weak base.
C) strong acid.
D) weak acid.
E) salt.

Question 37

When two monosaccharides undergo a dehydration synthesis,

A) a new monosaccharide is formed.
B) a disaccharide is formed.
C) a polysaccharide is formed.
D) a starch is formed.
E) hydrolysis occurs.

Question 38

The best definition of organic material is anything that

A) contains carbon.
B) contains carbon, oxygen, and hydrogen covalently bonded.
C) contains carbon, nitrogen, and hydrogen covalently bonded.
D) contains hydrogen covalently bonded.
E) contains carbon and hydrogen covalently bonded.

Question 39

A decrease of hydrogen ions in the body fluids can have disastrous results because

A) decreased hydrogen ions can break chemical bonds.
B) decreased hydrogen ions can change the shape of large complex molecules, rendering them nonfunctional.
C) decreased hydrogen ions can disrupt tissue functions.
D) decreased hydrogen ions can kill living cells.
E) all of the above

Question 40

Which of the following is inorganic?

A) hydrogen
B) oxygen
C) carbon
D) calcium
E) none of the above

Question 41

A fatty acid that contains only single covalent bonds in its carbon chain is said to be

A) saturated.
B) polyunsaturated.
C) monounsaturated.
D) hydrogenated.
E) carboxylated.

Question 42

A disaccharide is

A) starch.
B) glycogen.
C) fructose.
D) cellulose.
E) sucrose.

Question 43

The most important metabolic fuel molecule in the body is

A) sucrose.
B) starch.
C) protein.
D) vitamin B₁₂.
E) glucose.

Question 44

Enzymes

A) are lipids.
B) function as biological catalysts.
C) raise the activation energy for a reaction.
D) are carbohydrates.
E) all of the above

Question 45

Which is a characteristic of carbon dioxide?

A) It is composed of polar molecules.
B) It can pass easily through a cell membrane.
C) It is required by the body.
D) It makes up a majority of the atmosphere.
E) It is a nutrient.

Question 46

Which of the following is a function of proteins?

A) support
B) transport
C) metabolic regulation
D) movement
E) all of the above

Question 47

Proteins are composed of units called

A) amino acids.
B) simple sugars.
C) fatty acids.
D) adenosines.
E) nucleotides.

Question 48

During ionization, water molecules disrupt the ionic bonds of a solute, resulting in a mixture of ions. These ions are called

A) cations.
B) anions.
C) dissociates.
D) electrolytes.
E) anti-ions.

Question 49

The group of organic compounds containing mostly carbon and hydrogen with small amounts of oxygen is defined as a

A) carbohydrate.
B) lipid.
C) protein.
D) nucleic acid.
E) none of the above

Question 50

According to the rules of complementary base pairing, a nucleotide containing the base cytosine would only pair with a nucleotide containing the base

A) thymine.
B) adenine.
C) uracil.
D) cytosine.
E) guanine.

Question 51

Molecules that perform most cellular "work" are called

A) proteins.
B) nucleic acids.
C) carbohydrates.
D) steroids.
E) lipids.

Question 52

A class of lipids used to signal cells to undergo changes is called

A) steroids.
B) phospholipids.
C) triglycerides.
D) hormones.
E) monoglycerides.

Question 53

Carbohydrate molecules may be used for which of the following?

A) a primary energy storage molecule
B) part of nucleic acid structure
C) the body's most important source of energy
D) receptors of the cell surface
E) all of the above

Question 54

Lipids are used for which of the following?

A) form essential structural components of cells
B) provide roughly 10 times as much energy as carbohydrates
C) help reduce body temperature
D) help protect the skeleton
E) carry genetic information

Question 55

A DNA nucleotide consists of

A) a five-carbon sugar and a phosphate group.
B) a five-carbon sugar and a nitrogen base.
C) a ribose sugar, a nitrogenous base, and a phosphate group.
D) a deoxyribose sugar, a nitrogenous base, and a phosphate group.
E) a five-carbon sugar and an amino acid.

Question 56

Which of the following can be denatured?

A) enzymes.
B) ions.
C) atoms.
D) molecules.
E) none of the above

Question 57

If a polypeptide contains 9 peptide bonds, how many amino acids does it contain?

A) 0
B) 5
C) 10
D) 11
E) 12

Question 58

A bond between a phosphate group and a sugar can be found linking together

A) two simple sugars.
B) one amino acid to an amino group of another.
C) two nucleotides.
D) a fatty acid and a glycerol molecule.
E) a cholesterol molecule and a fatty-acid molecule.

Question 59

Each amino acid forms bonds by connecting its carboxyl group to the next amino acid's

A) central carbon atom.
B) amino group.
C) carboxyl group.
D) R group.
E) hydroxide group.

Question 60

Substrate molecules bind to enzymes at the

A) allosteric sites.
B) active sites.
C) reaction sites.
D) modification sites.
E) none of the above

Question 61

The nucleic acid DNA

A) is double stranded.
B) contains uracil in place of thymine.
C) contains the pentose ribose.
D) contains protein bases.
E) synthesizes lipids.

Question 62

In living cells, complex reactions proceed in a sequence of interlocking steps called a metabolic _________________________.

Question 63

A(n) _________________________ contains atoms with the same atomic number.

Question 64

Which of the following is unique to RNA?

A) glucose
B) phosphate group
C) ribose
D) adenosine triphosphate
E) deoxyribose

Question 65

The area around the center of an atom that contains negatively charged subatomic particles is called the electron _________________________.

Question 66

In a _________________________ reaction, bonds between atoms are broken and atoms are rearranged into new combinations.

Question 67

Atoms of the same element have the same number of _________________________ but may have a different number of _________________________.

Question 68

Elements that form anions tend to be found on the _________________________ side of the periodic table.

Question 69

Ions with a positive charge are called _________________________.

Question 70

Chemical reactions that require an input of energy are said to be _________________________.

Question 71

_________________________ are compounds that maintain pH of solutions within given limits.

Question 72

The most acidic solution would have a pH of _________________________.

Question 73

A mixture of water and a salt would result in breaking down the salt. This process is called _________________________.

Question 74

Reactions that result in larger molecules formed from smaller ones are called _________________________ reactions.

Question 75

Chemical reactions that occur in the human body are controlled by special protein molecules called _________________________.

Question 76

_________________________ compounds do not contain carbon as the primary structural atom.

Question 77

Amino acids contain a central carbon atom adjacent to a(n) _________________________ group and a(n) _________________________ group.

Question 78

_________________________ are soluble inorganic compounds whose ions will conduct an electric current in solutions.

Question 79

A molecule containing two atoms of hydrogen and one atom of oxygen in combination is called a(n) _________________________.

Question 80

The term that applies to all of the decomposition reactions that occur in metabolism is _________________________.