Deck 2: Molecules of Life

Question 1

The nucleus of an atom contains

A) protons
B) electrons
C) neutrons
D) protons and neutrons
E) protons and electrons

Answer 1

D

Question 2

The neutral subatomic particle is

A) the neutron.
B) the proton.
C) the electron.
D) both the electron and the proton.
E) both the neutron and the electron.

Answer 2

A

Question 3

The amount of energy necessary for an electron to jump to its next level

A) varies depending on the atom.
B) is exactly equal to what it needs.
C) is always in excess of the needed amount.
D) is exactly twice the energy emitted when the electron loses energy.
E) is less than the energy emitted when the electron loses energy.

Answer 3

B

Question 4

Eating as little as ___ grams of trans fats can increase a person's risk for a variety of diseases.

A) one
B) two
C) three
D) four
E) five

Question 5

Which of the following inventions led to trans fats being marketed as a solid cooking fat?

A) the electric light
B) the telephone
C) the automobile
D) the microwave oven
E) the refrigerator

Question 6

Which of the following is NOT a disease associated with excess consumption of trans fats?

A) atherosclerosis
B) heart attack
C) diabetes
D) arthritis
E) all of these are diseases associated with consumption of trans fats

Question 7

In an atom, ____ spin around the nucleus.

A) electrons
B) protons
C) neutrons
D) both neutrons and protons
E) both protons and electrons

Question 8

What are the properties that favor trans fat over other types of fats?
I. long shelf-life
II. cheaper than butter
III. mild flavor
IV. healthier

A) I and II
B) I, II, and III
C) I, II, III, and IV
D) II and III
E) II only

Question 9

The negative subatomic particle is

A) the neutron.
B) the proton.
C) the electron.
D) both the electron and the proton.
E) both the proton and the electron.

Question 10

The positive subatomic particle is

A) the neutron.
B) the proton.
C) the electron.
D) both the electron and the proton.
E) both the neutron and the electron.

Question 11

The average American consumes about ____ pounds of fat per year.

A) 100
B) 80
C) 70
D) 50
E) 20

Question 12

Oxygen has an atomic number of 8. This means that oxygen has 8

A) electrons in its outer most shell.
B) neutrons in its nucleus.
C) protons and 8 neutrons in its nucleus.
D) protons in its nucleus.
E) neutrons in its outer shell.

Question 13

A fat molecule has ____ fatty acids.

A) 1
B) 2
C) 3
D) 4
E) 5

Question 14

The human body requires about ____ of fat each day to stay healthy.

A) 1 teaspoon
B) 4 teaspoons
C) 1 tablespoon
D) 4 tablespoons
E) 1 cup

Question 15

A hydrogen atom that has become an ion is

A) a negatively charged ion.
B) an isotope.
C) unstable.
D) a proton.
E) an electron.

Question 16

Hydrogenated vegetable oil or trans fats are

A) as healthy as natural vegetable oil.
B) as healthy as animal fats.
C) more healthy than animal fats.
D) less healthy than animal fats or vegetable oils.
E) more healthy than vegetable oils.

Question 17

Which of the following is true about the metabolism of trans fatty acids?

A) we have evolved the enzymes to hydrolyze trans fatty acids
B) we have enzymes to hydrolze cis fatty acids but not trans fatty acids
C) we can metabolize about half of the trans fatty acids we consume but no more than that
D) we cannot metabolize either cis or trans fatty acids
E) more than one of these is correct

Question 18

Fats are major components of the cell's

A) membranes.
B) cytoplasm.
C) proteins.
D) ribosomes.
E) mitochondria.

Question 19

An atom is in its most stable state when

A) the number of electrons equals the number of protons.
B) the number of neutrons equals the number of protons plus number of electrons.
C) there are electron vacancies in the inner most shell.
D) there are no electron vacancies in the outer shell.
E) more than one of these is possible.

Question 20

Atomic isotopes

A) are electrically unbalanced.
B) behave the same chemically and physically but differ biologically from other isotopes.
C) are the same physically and biologically but differ from other isotopes chemically.
D) have varying numbers of neutrons.
E) are produced when substances are exposed to radiation.

Question 21

Which of the following statements is (are) TRUE about radioisotopes?

A) Radioisotope decays at a constant rate.
B) Decay of a radioisotope is independent of temperature.
C) Decay of a radioisotope is independent of pressure.
D) A radioisotope decays into a predictable product.
E) All of these are true.

Question 22

Tracer isotopes

A) are used only in plants.
B) work differently than nontracers in reactions.
C) have an unbalanced electrical charge.
D) are detected by their radioactivity.
E) are not found in nature.

Question 23

Radioactive isotopes have

A) excess electrons.
B) excess protons.
C) excess neutrons.
D) insufficient neutrons.
E) insufficient protons.

Question 24

In which of the following biological systems have radioactive tracers been used?

A) cells
B) bodies
C) ecosystems
D) all of these
E) all of these except ecosystems

Question 25

What type of chemical bonds are found within a water molecule?

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

Question 26

Carbon 14 radioisotopes decay into stable

A) carbon 13 isotopes.
B) nitrogen atoms.
C) carbon atoms.
D) nitrogen 15 isotopes.
E) sodium atoms.

Question 27

Phosphorus Consider the element phosphorus, which has an atomic mass of 30, and answer the following question(s). How many protons are in the nucleus of a phosphorus atom?

A) 5
B) 7
C) 10
D) 15
E) 30

Question 28

Electrons are shared in bonds called

A) covalent bonds.
B) ionic bonds.
C) polar bonds.
D) nonpolar bonds.
E) all of these except ionic bonds.

Question 29

A(n) ____ is a type of chemical bond in which a strong mutual attraction forms between ions of opposite charge.

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

Question 30

An atom that carries a charge is called a(n)

A) ion.
B) molecule.
C) compound.
D) element.
E) microelement.

Question 31

The positively charged ion, potassium, and the negatively charged ion, fluoride, will form what kind of bond?

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

Question 32

Phosphorus Consider the element phosphorus, which has an atomic mass of 30, and answer the following question(s). Phosphorus has ____ electron vacancies.

A) 1
B) 2
C) 3
D) 5
E) 8

Question 33

Phosphorus Consider the element phosphorus, which has an atomic mass of 30, and answer the following question(s). How many electrons are in the second electron shell of a phosphorus atom?

A) 1
B) 2
C) 3
D) 5
E) 8

Question 34

Phosphorus Consider the element phosphorus, which has an atomic mass of 30, and answer the following question(s). How many electrons are in the innermost electron shell of a phosphorus atom?

A) 1
B) 2
C) 3
D) 5
E) 8

Question 35

Boron has an atomic number of 5. How many vacancies does boron have in its outer shell?

A) 1
B) 2
C) 3
D) 4
E) 5

Question 36

For a given element, all atoms of that element have the same number of

A) neutrons.
B) electrons.
C) protons.
D) protons and neutrons.
E) ions.

Question 37

Which of the following statements is NOT true?

A) All isotopes of an element have the same number of electrons.
B) All isotopes of an element have the same number of protons.
C) All isotopes of an element have the same number of neutrons.
D) All radioisotopes are unstable.
E) All isotopes of an element have the same atomic number.

Question 38

Instability of radioisotopes is caused by

A) sudden temperature variations.
B) environmental humidity.
C) the random motion of atoms.
D) the disintegration of a neutron into a proton and an electron.
E) the motion of electrons and neutrons.

Question 39

The bond in table salt (NaCl) is

A) polar.
B) ionic.
C) covalent.
D) double.
E) nonpolar.

Question 40

In ____ bonds, atoms share electrons equally.

A) double covalent
B) unstable covalent
C) polar covalent
D) nonpolar covalent
E) triple covalent

Question 41

Which of the following bonds is weakest?

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

Question 42

Which compound is NOT soluble in water?

A) olive oil
B) table salt
C) sugar
D) albumin
E) sucrose

Question 43

A hydrogen bond is

A) a sharing of a pair of electrons between a hydrogen and an oxygen nucleus.
B) a sharing of a pair of electrons between a hydrogen nucleus and either an oxygen or a nitrogen nucleus.
C) an attractive force that involves a hydrogen atom and an oxygen or a nitrogen atom that are either in two different molecules or within the same molecule.
D) none of these.
E) all of these.

Question 44

____ is the tendency of water molecules to stay attached to one another.

A) Adhesion
B) Cohesion
C) Fusion
D) Interaction
E) Junction

Question 45

Hydrophobic molecules are ____ water.

A) attracted by
B) absorbed by
C) repelled by
D) mixed with
E) polarized by

Question 46

Water is an excellent solvent because

A) it forms spheres of hydrogenation around charged substances pulling their individual molecules away from one another.
B) it forms hydrogen bonds with many substances.
C) it has a high-heat containing property.
D) of its polarity.
E) of all of these.

Question 47

Which of the following substances is hydrophobic?

A) canola oil
B) sodium chloride
C) sugar
D) water
E) the potassium ion

Question 48

Which property of water molecules is responsible for movement of water from roots to leaves in a plant?

A) hydrophobicity
B) temperature stability
C) fusion
D) solvent polarity
E) cohesion

Question 49

Fats will dissolve in ethanol. Ethanol is an example of a

A) solute
B) solution
C) solvent
D) salt
E) ion

Question 50

A liquid that can dissolve other substances is called a

A) compound.
B) mixture.
C) solvent.
D) solute.
E) solution.

Question 51

A substance that is dissolved by a liquid is called a

A) compound.
B) mixture.
C) solvent.
D) solute.
E) solution.

Question 52

Methane gas (CH₄) is an example of a molecule containing which type of chemical bonds?

A) hydrogen bonds
B) double bonds
C) ionic bonds
D) polar covalent bonds
E) nonpolar covalent bonds

Question 53

Which of the following is true of water molecules when water becomes ice?

A) the water molecules jiggle more
B) their structure becomes less rigid
C) the water molecules pack less densely
D) hydrogen bonds between water molecules readily break
E) evaporation of water molecules happens more readily

Question 54

A mix of glucose and water is called a

A) compound.
B) suspension.
C) solvent.
D) solute.
E) solution.

Question 55

____ bonds hold molecules of water together.

A) Hydrogen
B) Ionic
C) Covalent
D) Inert
E) Single

Question 56

Chemical bonds are based on attractions between the ____ of two atoms.

A) electrons and protons
B) protons
C) protons and neutrons
D) electrons
E) neutrons

Question 57

Which types of bonds are possible between a hydrogen atom and another atom within the same molecule?

A) hydrogen only
B) single bonds only
C) single bonds and double bonds
D) single, double, and triple bonds
E) single, double, triple, and hydrogen bonds

Question 58

A water molecule is polar because

A) the oxygen atom is a negative ion and the hydrogen atoms are positive ions.
B) both the oxygen and the hydrogens are negatively charged.
C) oxygen has a magnetic charge.
D) the electrons of the hydrogen atoms are pulled to the oxygen atom.
E) hydrogen has a stronger pull on the electrons than does oxygen.

Question 59

Which of the following is TRUE about water?

A) The oxygen end is slightly electropositive.
B) Hydrogen bonds hold water molecules together.
C) Water covers about one-half of the surface of the earth.
D) Hydrophobic interactions attract water molecules.
E) Solvent properties are greatest with nonpolar molecules.

Question 60

Which of the following bonds is weakest?

A) between two oxygen atoms within molecular oxygen
B) between the opposite ions, sodium and chloride
C) between the oxygen and hydrogens within a water molecule
D) between two water molecules
E) between the hydrogens within molecular hydrogen

Question 61

Which of the following is a monomer of carbohydrates?

A) triglyceride
B) fatty acids
C) nucleotide
D) amino acid
E) monosaccharide

Question 62

The breakdown of large molecules by the enzymes and with the addition of water is what kind of reaction?

A) oxidation
B) reduction
C) condensation
D) hydrolysis
E) decarboxylation

Question 63

Large polymers are formed from smaller sub-units by what type of reaction?

A) oxidation
B) reduction
C) condensation
D) hydrolysis
E) decarboxylation

Question 64

What category of compounds helps our body fluids to stay within a consistent pH range?

A) solvents
B) buffers
C) solutes
D) acids
E) bases

Question 65

What part does carbon play in the structure of biological molecules?

A) carbon forms their backbone
B) carbon provides polarity
C) carbon makes it easier for them to be digested
D) carbon forms a bridge between two monomers
E) carbon plays no role whatsoever in the structure of biological molecules

Question 66

Which of the following pHs has the highest concentration of hydrogen ions?

A) 1
B) 3
C) 5
D) 7
E) 9

Question 67

A solution with a pH of 8 has how many times fewer hydrogen ions than a solution with a pH of 6?

A) 2
B) 5
C) 10
D) 100
E) 1,000

Question 68

A pH of 10 is how many times as basic as a pH of 7?

A) 2
B) 3
C) 10
D) 100
E) 1,000

Question 69

Which of the following pHs is the most acidic?

A) 1
B) 3
C) 5
D) 7
E) 9

Question 70

Cellular pH is kept near a value of 7 by the action of

A) salts.
B) buffers.
C) acids.
D) bases.
E) water.

Question 71

Which of the following compounds helps to maintain our blood pH between 7.35 and 7.45?

A) water
B) carbonic acid
C) hydrocloric acid
D) hydrogen peroxide
E) sodium hydroxide

Question 72

For which of the following pHs, is the hydroxide ion concentration greater than the hydrogen ion concentration?

A) 1
B) 3
C) 5
D) 7
E) 9

Question 73

Which of the following carbohydrates form highly branched chains of glucose monomers?

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

Question 74

What two atoms are found in all organic compounds?

A) carbon and hydrogen
B) carbon and oxygen
C) oxygen and hydrogen
D) carbon and phosphorous
E) oxygen and sulfur

Question 75

Which of the following is an organic molecule?

A) carbon dioxide (CO2)
B) water (H2O)
C) methane (CH4)
D) hydrochloric acid (HCl)
E) more than one of these is an organic molecule

Question 76

Glucose dissolves in water because it

A) ionizes.
B) is a polysaccharide.
C) is a polar and forms many hydrogen bonds with water molecules.
D) has a very reactive primary structure.
E) is an isotope.

Question 77

The property of water that helps cool our skin when we sweat is

A) cohesion.
B) evaporation.
C) temperature stabilization.
D) lattice packing.
E) solvent power.

Question 78

Nearly all of life's chemistry occurs near which of the following pHs?

A) 1
B) 3
C) 5
D) 7
E) 9

Question 79

What accounts for carbon's importance to life?

A) its ability to form rings
B) its nonpolarity
C) its versatile bonding behavior
D) its ability to form rings
E) its large size

Question 80

What are the monomers of carbohydrates?

A) disaccharides
B) monosaccharides
C) fatty acids
D) amino acids
E) nucleotides