Deck 2: The Chemistry of Life

Question 1

A hydrogen bond

A)is generally a strong bond.
B)does not occur in living organisms.
C)does not require electron transfer.
D)forms between atoms having the same electronegativity.
E)is a specialized type of covalent bond.

Answer 1

C
Explanation: Hydrogen bonds form between adjacent water molecules due to the polar nature of their covalent bonds.Please see section 2.2 for more information.

Question 2

In the example of ionic bond formation between sodium and chlorine

A)Na is the chemical symbol for chlorine.
B)sodium accepts an electron.
C)chlorine accepts an electron.
D)chlorine becomes positively chargeD.
E)both sodium and chlorine accept electrons.

Answer 2

C
Explanation: In forming the bond in sodium chloride,sodium donates an electron which chlorine accepts.Please see section 2.2 for more information.

Question 3

If a covalent bond is polar

A)electrons are not shared by atoms.
B)protons are shared by atoms.
C)it will not form in living organisms.
D)the electronegativity of atoms is unequal in their pull on electrons.
E)the bond is weak in strength.

Answer 3

D
Explanation: When bonded atoms pull unequally on electrons,the resulting covalent bond is polar,with a net partial charge on each atom.Please see section 2.2 for more information.

Question 4

An ion could be

A)an atom that has gained electrons.
B)an atom that has a positive charge.
C)an atom that has lost electrons.
D)an atom that has a negative charge.
E)All answers are correct.

Question 5

If you were writing the answer key for a professor's exam,and one question asked students to mark a box for the number of outer shell electrons possessed by an element having the maximum number,you would have the key say that the correct answer was

A)one electron.
B)two electrons.
C)four electrons.
D)eight electrons.
E)sixteen electrons.

Question 6

Which statement about a bond between sodium and chlorine would lose points on an exam?

A)Na is the chemical symbol for sodium.
B)Chlorine donates an electron.
C)Chlorine becomes negatively charged.
D)Sodium becomes positively chargeD.
E)The bond that is formed is a strong bond.

Question 7

An ionic bond is a bond in which

A)atoms share electrons.
B)atoms share protons.
C)atoms of opposite charges attract each other.
D)atoms share neutrons.
E)atoms are repelled by each other.

Question 8

Evaporation is

A)the conversion of a liquid into a vapor.
B)the conversion of a solid into a vapor.
C)the conversion of a vapor into a liquid.
D)the conversion of a vapor into a soliD.
E)All answers are correct.

Question 9

A friend who is not taking your Biology course fills a cup with ice and then a drink.The friend asks you why the ice in the cup is floating,and you are able to say that

A)the molecules are closer together in ice than in liquid water.
B)the molecules are farther apart in ice than in liquid water.
C)ice is denser than liquid water.
D)convection currents caused by temperature differences push upwards on the ice.
E)water vapor is less dense than liquid water.

Question 10

A substance with a pH of 2 is

A)neutral.
B)a weak acid.
C)a weak base.
D)a strong base.
E)a strong acid.

Question 11

A base

A)has a value of 7 on the pH scale.
B)is a chemical that adds hydrogen ions to a solution.
C)is a chemical that absorbs hydrogen ions from a solution.
D)has a value below 7 on the pH scale.

Question 12

Isotopes of the same element are different from one another in that

A)they have a different number of protons.
B)they have a different number of neutrons.
C)they have a different number of electrons.
D)they are a different element.
E)only one of the isotopes is matter.

Question 13

An acid

A)has a value above 7 on the pH scale.
B)is a chemical that takes hydrogen ions from a solution.
C)has a value of 7 on the pH scale.
D)is a chemical that adds hydrogen ions to a solution.
E)All answers are correct.

Question 14

The atomic number of an atom or element is

A)the number of neutrons in the nucleus.
B)the number of electrons in the nucleus.
C)the number of protons in the nucleus.
D)the number of neutrons in the orbitals.
E)the number of protons in the orbitals.

Question 15

If you were told to sort cards to into boxes after a lab on elements,you would put into a slot labelled "Mass Number" any card with text that meant

A)the total number of protons,neutrons,and electrons of an atom.
B)the total number of protons and electrons of an atom.
C)the total number of protons and neutrons of an atom.
D)the total number of neutrons and electrons of an atom.
E)the total number of protons of an atom.

Question 16

The primary elements making up living organisms are

A)carbon,hydrogen,oxygen,and calcium.
B)carbon,oxygen,iron,and chlorine.
C)carbon,hydrogen,iron,and calcium.
D)carbon,hydrogen,oxygen,and nitrogen.
E)carbon,oxygen,sulfur,and calcium.

Question 17

In a chemical equation

A)the reactants are on the right of the yields arrow.
B)reactants and products are on both sides of the yields arrow.
C)the products are on the left of the yields arrow.
D)the reactants are on the left of the yields arrow.
E)the number of atoms of each element may differ on the two sides of the yields arrow.

Question 18

As part of an exam,you are given a powder to analyze.When you perform various tests,you find that it contains a single chemical that changes the pH of neutral water to a pH of 6.You would conclude that the chemical is a

A)weak acid.
B)neutral.
C)weak base.
D)strong aciD.
E)strong basE.

Question 19

In a covalent bond

A)atoms share electrons.
B)atoms of opposite charges attract each other.
C)atoms share protons.
D)atoms share neutrons.
E)atoms are repelled by each other.

Question 20

If an atom has a valence shell that is full,then it

A)is highly reactive.
B)is chemically unstable.
C)is highly likely to combine with other atoms.
D)is found only in a gas form.
E)is inert.

Question 21

You are asked to help solve a murder,and a note from the murdered taunting the police says that the crime was committed using a lipid.What molecule could you exclude from your search?

A)a triglyceride
B)a phospholipid
C)a wax
D)a sterol
E)a starch molecule

Question 22

If asked to build a model of an amino acid,you would need parts to represent

A)three R groups and a glycerol.
B)nitrogen,carbon,and an R group.
C)multiple saccharide rings.
D)carbon and phosphorus monomers.
E)carbon and phosphorus.

Question 23

As part of a lab practical,you are asked to attach explanation to labels on chemical models.To the link between amino acids in a protein you would add a label describing that it is

A)an ionic bond in proteins.
B)a covalent bond in carbohydrates.
C)a covalent bond in proteins.
D)an ionic bond in carbohydrates.
E)a hydrogen bond in nucleic acids.

Question 24

Which of the following is NOT an example of matter?

A)wind
B)energy
C)light
D)sound
E)None of the answers are correct.

Question 25

A substance with a pH of 7 is

A)a weak acid.
B)a weak base.
C)neutral.
D)a strong aciD.
E)a strong basE.

Question 26

You are asked to help prepare a lab and need to label some beakers.In one,you are told,there are sugars polymerizing into a large polymer,so you prepare a label that mentions

A)hydrolysis.
B)reproduction.
C)dehydration synthesis.
D)hydrolysis and dehydration synthesis.
E)unrelated to chemical bonds.

Question 27

You can painlessly wade into a pool,but doing a belly flop off of the high diving board hurts because of

A)water's high density.
B)adhesion of your molecules with the water molecules.
C)water's high boiling point.
D)a neutral pH.
E)cohesion of the water molecules.

Question 28

The primary building block (monomer)of nucleic acids is

A)a nucleotide.
B)a glucose molecule.
C)a fatty acid.
D)an amino aciD.
E)four interconnected carbon rings.

Question 29

What do a lemon,a toaster oven,and sand grains have in common?

A)All are composed of matter and energy.
B)All are alive.
C)All are composed of organic molecules.
D)All are acidic.
E)All are basic.

Question 30

You have been presented with a new compound that is bright purple and that smells of violets.However,it sticks to surfaces in a way similar to water and can replace water in the running of living cells.You might then expect this new molecule to make

A)covalent bonds.
B)ionic bonds.
C)hydrogen bonds.
D)hydrophobic bonds.
E)peptide bonds.

Question 31

A process by which cells break polymers down into smaller units is

A)hydrolysis.
B)dehydration synthesis.
C)reproduction.
D)hydrolysis and dehydration synthesis.
E)unrelated to chemical bonds.

Question 32

Within a single molecule of water,____ bonds are formed between oxygen and hydrogen.

A)ionic
B)covalent
C)hydrogen
D)hydrophobic
E)nuclear

Question 33

The four major groups of organic compounds are

A)fats,waxes,carbohydrates,and amino acids.
B)carbohydrates,lipids,steroids,and monosaccharides.
C)lipids,fats,waxes,and steroids.
D)carbohydrates,lipids,proteins,and nucleic acids.
E)carbohydrates,proteins,amino acids,and nucleic acids.

Question 34

The most common isotope of carbon is ¹²C.¹⁴C has ____ than ¹²C.

A)more protons
B)more neutrons
C)fewer neutrons
D)fewer protons
E)more electrons

Question 35

Imagine that you are in a study session,and your group is taking a practice quiz that members grade for one another.For the question,"A cook decides to cook only using monomers,so what chemicals could the cook use?" you would mark correct if the paper you are grading has this answer as

A)cellulose and sucrose.
B)lactose and sucrose.
C)glucose and fructose.
D)glucose and cellulose.
E)None of the answers are correct.

Question 36

Organic molecules are defined as chemical compounds that contain

A)hydrophilic solutions.
B)isotopes of carbon.
C)ionically bonded atoms.
D)strong hydrogen bonds.
E)carbon and hydrogen.

Question 37

The primary building block (monomer)of proteins is

A)a glucose molecule.
B)a fatty acid.
C)a nucleotide.
D)an amino aciD.
E)four interconnected rings.

Question 38

Water is best described as which of the following?

A)an ion
B)a nonpolar molecule
C)an atom
D)a polar molecule
E)an element

Question 39

As part of a lab exam,you are given a vial of orange crystals.When you add them to pure,neutral pH water,the pH changes to 13.Other tests show that the crystals consist of as single chemical,which you could conclude is

A)a weak acid.
B)a weak base.
C)neutral.
D)a strong aciD.
E)a strong basE.

Question 40

¹⁴C and ¹⁴N have the same

A)atomic number.
B)number of protons.
C)atomic mass.
D)number of neutrons.
E)number of electrons.

Question 41

The polymers with the most complex and diverse three-dimensional structures are

A)saturated fats.
B)unsaturated fats.
C)proteins.
D)waxes.
E)carbohydrates.

Question 42

Hydrogen,nitrogen,carbon,and oxygen account for 96% of the human body.These elements are

A)also the main elements in organic molecules.
B)rare in nonhuman organisms.
C)rare on Earth.
D)always bonded by hydrogen bonds.
E)All answers are correct.

Question 43

If you wanted to add a factor to a culture grasshoppers to see if it might cause a color change,what might you try?

A)bacteria
B)seeds
C)caffeine
D)salt
E)wax

Question 44

Water is a compound.

Question 45

If you sprayed antibiotics on purple insects,and they changed color,what did the antibiotics most likely affect?

A)bacteria
B)seeds
C)caffeine
D)salt
E)wax

Question 46

Some aphids can change color in response to the presence of bacterial symbionts.

Question 47

Two hydrogen atoms and an oxygen atom bonded together form

A)a molecule,but not a compound.
B)a compound,but not a molecule.
C)a molecule and a compound.
D)an atom and a molecule.
E)an atom,but not a molecule or compound.

Question 48

Polymers are made of monomers,and both are kinds of compounds.

Question 49

If you add a factor to a culture of sap-sukcing mealy bugs,and they change color from red to green,what might you have added?

A)bacteria
B)seeds
C)caffeine
D)salt
E)wax

Question 50

Proteins are compound because they are polymers.

Question 51

Color changes are not connected to their survival.

Question 52

Carbon is a compound.

Question 53

Aphids that change color in response to the presence of bacterial symbionts generally do so as they age.