Deck 2: The Chemistry of Life

Question 1

Two or more atoms of the same element that are chemically combined are known as:

A) compounds.
B) suspensions.
C) ions.
D) molecules.

Answer 1

D

Question 2

Atoms that satisfy the octet rule are said to be:

A) isotopes.
B) ions.
C) reactive.
D) inert.

Answer 2

C

Question 3

The formation of a cation and an anion is indicative of a(n):

A) nonpolar bond.
B) ionic bond.
C) polar bond.
D) covalent bond.

Answer 3

B

Question 4

The four most common elements, comprising 96% of the body's mass, are:

A) oxygen, potassium, iron, copper.
B) chlorine, sodium, magnesium, potassium.
C) carbon, sodium, phosphorus, sulfur.
D) oxygen, nitrogen, hydrogen, carbon.

Question 5

The atomic number represents the number of:

A) electrons in an atom.
B) protons and neutrons in the nucleus of an atom.
C) protons in an atom.
D) neutrons in an atom.

Question 6

An atom of iron has an atomic number of 26. Which of the following is TRUE?

A) Iron has 26 protons.
B) Iron has 13 electrons.
C) Iron has 13 protons and 13 electrons.
D) Iron has 13 protons and 13 neutrons.

Question 7

Which of the following is the same among isotopes of the same element?

A) atomic number
B) mass number
C) number of neutrons
D) both the number of neutrons and the mass number

Question 8

Interpret what is meant by carbon ^-13.

A) Carbon ^-13 represents an isotope of carbon with 13 protons.
B) Carbon ^-13 represents an isotope of carbon with a mass number of 13.
C) Carbon ^-13 represents the mass number of every atom of carbon.
D) Carbon ^-13 represents an isotope of carbon with an atomic number of 13.

Question 9

Two or more atoms of different elements that are chemically bonded together are known as:

A) compounds.
B) ions.
C) molecules.
D) macromolecules.

Question 10

What contributes to the calculation of the mass number?

A) sum of protons, neutrons, and electrons
B) sum of electrons and neutrons
C) sum of protons and electrons
D) sum of protons and neutrons

Question 11

What predicts the element to which an atom belongs?

A) total number of protons
B) total number of electrons
C) number of electrons in the first shell
D) total number of neutrons

Question 12

An atom has 3 electrons in its valence shell. What is the atomic number of this atom?

A) 3
B) 8
C) 7
D) 13

Question 13

Which of the following atoms is inert?

A) atomic number of 14
B) atomic number of 6
C) atomic number of 10
D) atomic number of 8

Question 14

Which subatomic particle carries a negative charge?

A) nucleus
B) proton
C) electron
D) neutron

Question 15

What is meant by N₂?

A) The atomic number of nitrogen is two.
B) Two nitrogen atoms formed a molecule.
C) The atomic mass of nitrogen is two.
D) Two nitrogen atoms form a compound.

Question 16

Glucose dissolves in the water of blood plasma. This mixture is best known as a(n):

A) solution.
B) aerosol.
C) suspension.
D) colloid.

Question 17

How many electrons are in the outermost shell of an atom with 15 electrons?

A) 2
B) 8
C) 5
D) 10

Question 18

Determine the number of protons in an isotope of nitrogen with an atomic number of 7 and a mass number of 14.

A) 10
B) 17
C) 14
D) 7

Question 19

The innermost shell of an atom holds:

A) 2 protons.
B) 6 electrons.
C) 8 electrons.
D) 2 electrons.

Question 20

An electrically neutral atom with an atomic number of 8 and a mass number of 17 has:

A) 9 electrons.
B) 8 protons.
C) 8 neutrons.
D) 17 protons.

Question 21

Which biological catalyst lowers the activation energy of a reaction?

A) enzyme
B) carbohydrate
C) lipid
D) salt

Question 22

Which of the following represents an exchange reaction?

A) AB ⁺ CD ^- BA ⁺ DC
B) A ⁺ B ^- AB
C) AB ⁺ CD ^- AD ⁺ BC
D) AB ^- A ⁺ B

Question 23

In the following chemical reaction, what is NaCl? NaOH ⁺ HCl ^- NaCl ⁺ H₂O

A) reactant
B) acid
C) product
D) water

Question 24

In a molecule of oxygen gas, the atoms of oxygen share electrons equally with one another. This statement best describes a(n):

A) polar covalent bond.
B) compound.
C) ionic bond.
D) nonpolar covalent bond.

Question 25

What type of reaction is A ⁺ B ⁺ energy ^- AB?

A) equilibrium reaction
B) catabolic reaction
C) exergonic reaction
D) endergonic reaction

Question 26

Which statement best describes enzyme function?

A) Enzymes speed chemical reactions by lowering the activation energy.
B) Enzymes can perform catabolic reactions only.
C) Enzymes chemically alter both the reactants and products.
D) One enzyme can work on thousands of different substrates.

Question 27

Which of the following increases the rate of a reaction?

A) increased reactant concentration
B) cold temperatures
C) absence of a catalyst
D) solid reactants

Question 28

The process of digesting food breaks large food particles into smaller particles. This example is best described as a(n):

A) catabolic reaction.
B) neutralization reaction.
C) exchange reaction.
D) anabolic reaction.

Question 29

Hydrogen bonds may occur between:

A) polar molecules.
B) ions.
C) nonpolar covalent molecules.
D) metals.

Question 30

What happens in oxidation ^-reduction (redox) reactions?

A) Electron exchange occurs.
B) Atoms are exchanged.
C) Energy is used since these are endergonic reactions.
D) Larger molecules are built from smaller subunits.

Question 31

The transfer of an electron from sodium to chlorine is an example of:

A) chemical energy.
B) mechanical energy.
C) electrical energy.
D) sound energy.

Question 32

What type of compound is NOT likely to dissolve in water?

A) nonpolar covalent compound
B) polar covalent compound
C) ionic compound
D) both polar and nonpolar covalent compounds

Question 33

What does this structural formula, N^÷N, indicate?

A) An ionic bond holds the two atoms of nitrogen together.
B) Three atoms of nitrogen are double bonded.
C) Two atoms of nitrogen share three pairs of electrons.
D) Two atoms of nitrogen are held together by hydrogen bonds.

Question 34

Ionic bonds result from:

A) weak attractions between polar molecules.
B) equal sharing of electrons between nonmetals.
C) unequal sharing of electrons between nonmetals.
D) the transfer of electrons from a metal to a nonmetal.

Question 35

Which of the following is the strongest bond?

A) hydrogen
B) single covalent
C) double covalent
D) ionic

Question 36

What property of water helps keep body temperature stabilized?

A) surface tension
B) universal solvent
C) polarity
D) heat capacity

Question 37

What is a dipole?

A) nonpolar molecule
B) a type of reaction
C) polar molecule
D) a salt

Question 38

Water is most likely to dissolve a solute that is:

A) hydrophobic.
B) hydrophilic.
C) a lipid.
D) nonpolar.

Question 39

What type of bond is responsible for the surface tension of water?

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

Question 40

Which of the following does NOT correctly describe water?

A) Water can dissolve ionic compounds.
B) Water has a low heat capacity.
C) Water cushions the body's structures.
D) Water is constructed of polar covalent bonds.

Question 41

What does ABC represent in the following reaction: A ⁺ B ⁺ C ^- ABC

A) product
B) reactant
C) enzyme
D) monomer

Question 42

Salts are held together by:

A) polar covalent bonds.
B) nonpolar covalent bonds.
C) single covalent bonds.
D) ionic bonds.

Question 43

When you soak dirty dishes in your kitchen sink, you allow the water to break apart the bonds of the food stuck to your plates. This type of reaction is known as:

A) neutralization.
B) dehydration synthesis.
C) hydrolysis.
D) anabolism.

Question 44

What chemical binds free hydrogen ions in solution?

A) acid
B) water
C) base
D) salt

Question 45

What does the ^H in the pH scale represent?

A) the negative logarithm
B) heat
C) concentration of H⁺ ions in solution
D) negative charge

Question 46

Which pH represents a solution that has the highest concentration of hydroxide ions?

A) pH 1
B) pH 10
C) pH 14
D) pH 7

Question 47

A solution containing equal number of hydrogen ions and hydroxide ions is:

A) neutral.
B) alkaline.
C) acidic.
D) basic.

Question 48

Ionic compounds dissociate in water into:

A) polar and nonpolar substances.
B) hydrophilic and hydrophobic substances.
C) acids and bases.
D) electrolytes.

Question 49

What is the function of a buffer?

A) Buffers absorb heat without changing temperature themselves.
B) Buffers act as a lubricant between two adjacent surfaces.
C) Buffers prevent large swings in pH when an acid or base is added to a solution.
D) Buffers lower the activation energy of a chemical reaction.

Question 50

Hydrochloric acid is a:

A) proton acceptor.
B) hydroxide ion donor.
C) hydrogen ion acceptor.
D) hydrogen ion donor.

Question 51

Which pH represents a solution that releases 100 times less hydrogen ions than a pH of 9?

A) pH 11
B) pH 7
C) pH 12
D) pH 8

Question 52

Which of the following represents the strongest acidic solution?

A) pH 9
B) pH 6
C) pH 4
D) pH 1

Question 53

What pH value represents a solution that releases 10 times more hydrogen ions than a pH of 7?

A) pH 5
B) pH 8
C) pH 6
D) pH 4

Question 54

Which two organ systems work to maintain pH balance in the body?

A) respiratory and urinary
B) endocrine and nervous
C) digestive and respiratory
D) urinary and endocrine

Question 55

The monomer of the carbohydrates is:

A) fatty acid.
B) monosaccharide.
C) nucleotide.
D) amino acid.

Question 56

On average, blood pH is approximately:

A) 7.4.
B) 7.6.
C) 7.1.
D) 7.8.

Question 57

Building blocks of organic molecules are known as:

A) enzymes.
B) monomers.
C) electrolytes.
D) polymers.

Question 58

On the pH scale, which number has the highest concentration of hydrogen ions?

A) pH 10
B) pH 1
C) pH 7
D) pH 5

Question 59

Select the simplest sugar:

A) lactose
B) sucrose
C) glucose
D) starch

Question 60

An important buffer system in the body is:

A) HCO₃ ^-.
B) NaOH.
C) HCl.
D) H₂O.

Question 61

Determine the atomic number of a neutral atom with 3 shells and 6 electrons in its valence shell.

Question 62

What is the building block of a lipid?

A) nucleic acid
B) fatty acid
C) glucose
D) glycogen

Question 63

Describe how a radioisotope achieves a more stable form.

Question 64

A long ^-lasting high fever is a concern for denaturation of:

A) saturated fats.
B) phospholipids.
C) enzymes.
D) glycogen.

Question 65

Most fat in our adipose tissue is in the form of:

A) steroids.
B) phospholipids.
C) triglycerides.
D) cholesterol.

Question 66

What group makes each amino acid unique?

A) amino group
B) ammonia group
C) "R" group
D) carboxylic acid group

Question 67

Amino acids are the monomers for:

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

Question 68

Explain how to determine the atomic number and mass number for an atom.

Question 69

What forms the basis for the body's steroids?

A) testosterone
B) glucose
C) cholesterol
D) triglyceride

Question 70

Glucose, galactose, and fructose have the molecular formula C₆H₁₂O₆ but have different arrangements of atoms. These sugars are:

A) disaccharides.
B) isomers.
C) polysaccharides.
D) isotopes.

Question 71

Which of the following lipids stores the most energy in the fatty acid chains?

A) monounsaturated fatty acid
B) saturated fatty acid
C) glycerol
D) polyunsaturated fatty acid

Question 72

A fatty acid that contains two or more double covalent bonds is:

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

Question 73

Yuri is working with a chemical in lab. This chemical is composed of repetitive units that include a phosphate group, a nitrogenous base, and a sugar known as ribose. He is working with:

A) a carbohydrate.
B) a protein.
C) a lipid.
D) a nucleic acid.

Question 74

The alpha ^-helix and beta ^-pleated sheet are examples of:

A) tertiary protein structure.
B) primary protein structure.
C) quaternary protein structure.
D) secondary protein structure.

Question 75

Through a dehydration synthesis reaction, a phosphate is added to ADP. What product is formed?

A) 2ADP
B) AMP
C) ATP
D) DNA

Question 76

What is the octet rule?

Question 77

What makes RNA a unique nucleic acid?

A) RNA is composed of two strands held together by hydrogen bonds.
B) RNA contains a sugar known as deoxyribose.
C) RNA contains a nitrogenous base known as uracil.
D) RNA is built from building blocks known as a nucleotide.

Question 78

Glucose and fructose are joined through dehydration synthesis to produce:

A) maltose.
B) galactose.
C) sucrose.
D) lactose.

Question 79

What type of polar covalent bond links amino acids?

A) hydrophobic bond
B) peptide bond
C) amphiphilic bond
D) ketone bond

Question 80

To make a gallon of lemonade, Emily mixed sugar with water until it dissolved. Did she create a solution, a suspension, or a colloid? Explain.