Deck 2: The Chemistry of Life

Question 1

During a chemical reaction,atoms are ________.

A) destroyed
B) created
C) rearranged
D) destroyed and created

Answer 1

C

Question 2

Which number represents the atomic weight of oxygen?

A) 6
B) 16
C) 18
D) Not enough information given

Answer 2

B

Question 3

Why is one side of a single water molecule partially negative while the other side is partially positive?

A) Electron pairs are unevenly shared between the oxygen atom and the two hydrogen atoms.
B) Electron pairs are unevenly shared between the two hydrogen atoms.
C) Oxygen donates its electrons to hydrogen.
D) Hydrogen donates its electrons to oxygen.

Answer 3

A

Question 4

The majority of the elements essential to life are found in what part of the periodic table?

A) The top third
B) The middle third
C) The bottom third
D) Evenly distributed throughout the periodic table

Question 5

Identify the part of the atom that most determines the chemical properties of the atom.

A) The number of shells
B) The number of protons
C) The number of neutrons
D) The number of electrons

Question 6

Which is not one of the four atoms that make up the bulk of living organisms?

A) Oxygen
B) Nitrogen
C) Calcium
D) Carbon

Question 7

The chemical name for table salt is sodium chloride,or simply NaCl.What type of chemical is NaCl?

A) Compound
B) Element
C) Molecule
D) Ion

Question 8

The typical carbon atom is described in the periodic table by the accompanying box.How many protons are in a typical oxygen atom?

A) 8
B) 12
C) 18
D) Not enough information given

Question 9

The 2+ in Cu²⁺ tells us that this atom ________.

A) has two more neutrons than protons
B) has two more protons than electrons
C) has two more electrons than neutrons
D) has two more electrons than protons

Question 10

Identify the reactants in the following chemical reaction: C₁₀H₈ + 12 O₂ → 10 CO₂ + 4 H₂O

A) C₁₀H₈ and 10 CO₂
B) 12 O₂ and 4 H₂O
C) C₁₀H₈ and 12 O₂
D) 10 CO₂ and 4 H₂O

Question 11

How many neutrons are in a typical oxygen atom?

A) 8
B) 12
C) 18
D) Not enough information given

Question 12

The bond in which bonded atoms share electrons is called a(n)________.

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

Question 13

Individual water molecules are held to one another by relatively weak ________ bonds.

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

Question 14

What is the most common element in your body?

A) Oxygen
B) Water
C) Carbon
D) Sugar

Question 15

If the number of protons in an atom does not match the number of electrons,the atom is called an ________.

A) element
B) isotope
C) isomer
D) ion

Question 16

In an atom,the number of neutrons determines most specifically the ________.

A) element
B) isotope
C) ion state
D) chemical properties

Question 17

What is the maximum number of single covalent bonds a carbon atom can form with other elements?

A) 1
B) 2
C) 3
D) 4

Question 18

What is a trace element?

A) An element that is very rare
B) An element that is evenly distributed on the planet
C) An element that is required in miniscule amounts for life
D) An element that is used to identify the location of other elements

Question 19

Water is the least dense when it ________.

A) freezes
B) is just above freezing
C) is at room temperature
D) is just below boiling

Question 20

While the maximum number of electrons required to fill the outermost shell of an atom varies depending on the size of the atom,almost all of the smaller atoms (atomic numbers 2-20)are considered stable (nonreactive)when they contain ________ electron(s)in the outermost shell.

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

Question 21

Based on the suffix,a molecule of "maltose" is most likely what type of macromolecule?

A) Carbohydrate
B) Lipid
C) Protein
D) Nucleic acid

Question 22

Water "beads up" on synthetic fabric such as polyester but binds to cotton.What is the most likely explanation for this?

A) Polyester is not a naturally occurring substance, whereas cotton is a naturally occurring substance.
B) Polyester is more flexible than cotton.
C) Polyester fibers are thinner than cotton fibers.
D) Polyester is nonpolar, whereas cotton is polar.

Question 23

Organic compounds are distinguished by molecules that contain ________ bonded to other elements.

A) nitrogen
B) carbon
C) oxygen
D) hydrogen

Question 24

Something with a pH of 5 would be ________.

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

Question 25

A needle can be made to "float" on the surface tension of water.What causes this surface tension to form?

A) The adhesion of water molecules to the needle
B) The cohesion of water molecules to each other
C) The solubility of water
D) The heat capacity of water

Question 26

Evaluate this statement: Cholesterol is a type of lipid,and thus all cholesterol lipids are bad for human health.

A) True, because high levels of cholesterol lead to increased heart disease.
B) True, because high levels of cholesterol lead to obesity.
C) False, because some types cholesterol increase heart disease, but other types are necessary, especially in the plasma membrane.
D) False, because cholesterol levels are not related to human health.

Question 27

The breaking of a large organic molecule into smaller,individual subunits involves multiple ________.

A) hydrolysis reactions
B) osmotic reactions
C) dehydration synthesis reactions
D) hydrosynthetic reactions

Question 28

What are the four classes of large organic molecules important to life on Earth?

A) Carbohydrates, lipids, proteins, and enzymes
B) Carbohydrates, lipids, proteins, and sugars
C) Carbohydrates, proteins, nucleic acids, and sugars
D) Carbohydrates, proteins, lipids, and nucleic acids

Question 29

The building of a large organic molecule from small subunits involves multiple ________.

A) hydrolysis reactions
B) osmotic reactions
C) dehydration synthesis reactions
D) hydrosynthetic reactions

Question 30

How do buffers minimize change in the pH of biological systems?

A) By absorbing H⁺ ions when there is an excess
B) By donating H⁺ ions when there is a shortage
C) Both of these
D) Neither of these

Question 31

What are the ecological consequences of acidification of rain and oceans?

A) They damage the health of ecosystems.
B) They do not have any consequences on ecosystems.
C) They improve the health of ecosystems.
D) Acid rain damages ecosystems, but ocean acidification improves the health of oceans.

Question 32

Which of the following represents a simple sugar (also called monosaccharides)?

A) Lactose
B) Cellulose
C) Glucose
D) Sucrose (table sugar)

Question 33

What is another name for the polymers of carbohydrates?

A) Triglycerides
B) Polysaccharides
C) Polypeptides
D) Nucleotides

Question 34

Which of the following is a polysaccharide?

A) Glucose
B) Cellulose
C) Fructose
D) Sucrose

Question 35

Select the most complete explanation of what the pH scale measures.

A) The acidity of a solvent
B) The alkalinity of a solvent
C) The concentration of hydrogen ions in a solution
D) The concentration of hydroxide ions in a solute

Question 36

What are the monomers of proteins?

A) Glucose
B) Nucleic acids
C) Fatty acids
D) Amino acids

Question 37

What is the sum total of all the chemical reactions that take place in your body called?

A) Catabolism
B) Anabolism
C) Embolism
D) Metabolism

Question 38

All lipids are ________.

A) water-loving molecules
B) hydrophilic
C) hydrophobic
D) hydrolytic

Question 39

Which of the following large organic molecules include table sugar?

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

Question 40

Which of the following is not made from long chains of glucose?

A) Starch
B) Monosaccharides
C) Glycogen
D) Cellulose

Question 41

Oil hydrogenation can produce a product,such as vegetable shortening or margarine,that is spreadable at room temperature because of an unusual bond that does not occur naturally.What is the name of this category of lipid?

A) Saturated fat
B) Healthy fat
C) Trans fat
D) Cholesterol

Question 42

The unique chemical qualities of individual amino acids do not directly determine the function of an enzyme.What,then,is the role of the individual amino acid's unique chemical qualities,and what directly determines the function of an enzyme?

Question 43

Which would have the highest concentration of C-H bonds?

A) Saturated fat
B) Unsaturated fat
C) Trans fat
D) Cholesterol

Question 44

Proteins are diverse molecules that perform a wide variety of functions.Which of the following is not a typical function of proteins?

A) Transport
B) Catalyze reactions via enzymes
C) Movement
D) Energy storage

Question 45

What is the basic structure of most lipids?

A) A glycerol head and up to three fatty acid tails
B) A linear chain of individual monomers
C) A branched chain of individual monomers
D) A chain of fatty acid tails

Question 46

Why does sweating cool your skin on a hot,dry day but make you feel warmer on a hot,humid day?

Question 47

To a large extent,a protein's function is dependent upon its shape.What determines a protein's shape?

A) The location of the active site
B) The sequence of amino acids
C) The number of amino acids
D) The number of peptide bonds

Question 48

Which of the following dietary fats is considered to be the least healthy?

A) Saturated fat
B) Unsaturated fat
C) Trans fat
D) Cholesterol

Question 49

An old home remedy for anemia was to drink from a jug of water into which was added a handful of iron nails.Why might this have been effective at treating certain forms of anemia?

Question 50

Organic molecules that end in the suffix "-ase" often function as ________ molecules.

A) structural
B) enzymatic
C) transport
D) storage

Question 51

What might happen if a protein has a change in one amino acid?

A) The amino acid chain folds incorrectly.
B) The protein can no longer function properly.
C) The protein has a new shape.
D) All of these happen.

Question 52

What kind of bond joins amino acids together to form a protein?

A) Peptide bond
B) Hydrogen bond
C) Polar bond
D) Protein bond

Question 53

Enzymes are a type of ________.

A) carbohydrate
B) protein
C) lipid
D) monomer

Question 54

Penicillin is a competitive inhibitor produced by a fungus in order to kill invading bacteria.It does this by mimicking the substrate required by the bacterium to build and repair its cell wall.Describe how mimicking the substrate would result in the death of the bacterium.

Question 55

What will be accomplished by lowering the activation energy of a reaction?

A) The reaction will proceed more slowly.
B) The reaction will proceed more quickly.
C) The reaction will stop completely.
D) The reaction will reverse.

Question 56

Which of the three gasses is the easiest to break apart: nitrogen gas (N₂),oxygen gas (O₂),or hydrogen gas (H₂)? Which is the most difficult to break apart? What accounts for the differences?