Deck 2: Chemistry Comes Alive

Question 1

Triglycerides are a poor source of stored energy.

Answer 1

False

Question 2

Hydrogen bonds are too weak to bind atoms together to form molecules, but they do hold different parts of a single large molecule in a specific three-dimensional shape.

Answer 2

True

Question 3

The fact that no chemical bonding occurs between the components of a mixture is the chief difference between mixtures and compounds.

Answer 3

True

Question 4

Mixtures are combinations of elements or compounds that are physically blended together but are not bound by chemical bonds.

Question 5

The lower the pH, the higher the hydrogen ion concentration.

Question 6

A dipeptide can be broken into two amino acids by dehydration synthesis.

Question 7

Covalent bonds are generally less stable than ionic bonds.

Question 8

O mega-3 fatty acids appear to decrease the risk of heart disease.

Question 9

Chemical properties are determined primarily by neutrons.

Question 10

All organic compounds contain carbon.

Question 11

Glycogen, the storage form of glucose, is primarily stored in skeletal muscle and liver cells.

Question 12

Phosphate.

Question 13

The acidity of a solution reflects the concentration of free hydrogen ions in the solution.

Question 14

Isotopes differ from each other only in the number of electrons the atom contains.

Question 15

A charged particle is generally called an ion or electrolyte.

Question 16

A chemical bond is an energy relationship between outer electrons and neighboring atoms.

Question 17

The pH of body fluids must remain fairly constant for the body to maintain homeostasis.

Question 18

About 60% to 80% of the volume of most living cells consists of organic compounds.

Question 19

Glucose is an example of a monosaccharide.

Question 20

It is the difference in the R group that makes each amino acid chemically unique.

Question 21

What happens in redox reactions?

A) the organic substance that loses hydrogen is usually reduced
B) the reaction is uniformly reversible
C) the electron acceptor is oxidized
D) both decomposition and electron exchange occur

Question 22

Choose the answer that best describes fibrous proteins.

A) are usually called enzymes
B) are cellular catalysts
C) rarely exhibit secondary structure
D) are very stable and insoluble in water

Question 23

In general, the lipids that we refer to as oils have ________.

A) a high water content
B) long fatty acid chains
C) unsaturated fatty acids
D) saturated fatty acids

Question 24

Which of the following statements is false?

A) When acids and bases are mixed, they react with each other to form water and a salt.
B) The pH of blood is slightly basic.
C) The more hydrogen ions in a solution, the more acidic the solution.
D) When the hydrogen ion concentration decreases, the hydroxyl ion concentration also decreases.

Question 25

Which of the following elements is necessary for proper conduction of nerve impulses?

A) P
B) I
C) Fe
D) Na

Question 26

Which of the following is a general function for a fibrous protein?

A) transport
B) catalysis
C) protein management
D) structural framework
E) body defense

Question 27

What structural level is represented by the coiling of the protein chain backbone into an alpha helix?

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

Question 28

Which of the following does not describe enzymes?

A) Some enzymes are protein plus a cofactor.
B) Enzymes work by raising the energy of activation.
C) Some enzymes are purely protein.
D) Each enzyme is chemically specific.

Question 29

The single most abundant protein in the body is ________.

A) hemoglobin
B) DNA
C) glucose
D) collagen

Question 30

Which of the following does not characterize proteins?

A) They have both functional and structural roles in the body.
B) They may be denatured or coagulated by heat or acidity.
C) They appear to be the molecular carriers of coded hereditary information.
D) Their function depends on their three-dimensional shape.

Question 31

What is a chain of more than 50 amino acids called?

A) triglyceride
B) protein
C) polysaccharide
D) nucleic acid

Question 32

Which of the following is the major positive ion outside cells?

A) potassium
B) sodium
C) hydrogen
D) magnesium

Question 33

Carbohydrates are stored in the liver and skeletal muscles in the form of ________.

A) cholesterol
B) glycogen
C) glucose
D) triglycerides

Question 34

The basic structural material of the body consists of ________.

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

Question 35

Which statement about enzymes is false?

A) Most enzymes can catalyze millions of reactions per minute.
B) Enzymes require contact with substrate in order to assume their active form.
C) Enzymes may be damaged by high temperature.
D) Enzymes may use coenzymes derived from vitamins or cofactors from metallic elements.

Question 36

A chemical reaction in which bonds are broken is usually associated with ________.

A) the consumption of energy
B) forming a larger molecule
C) a synthesis
D) the release of energy

Question 37

The genetic information is coded in DNA by the ________.

A) three-dimensional structure of the double helix
B) sequence of the nucleotides
C) arrangement of the histones
D) regular alteration of sugar and phosphate molecules

Question 38

Salts are always________.

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

Question 39

Which of the following statements is false?

A) Chemical reactions progress at a faster rate when the reacting particles are present in higher numbers.
B) Chemical reactions proceed more quickly at higher temperatures.
C) Larger particles move faster than smaller ones and thus collide more frequently and more forcefully.
D) Catalysts increase the rate of chemical reactions, sometimes while undergoing reversible changes in shape.

Question 40

The numbers listed represent the number of electrons in the first, second, and third energy levels, respectively. On this basis, which of the following is an unstable or reactive atom?

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

Question 41

In a DNA molecule, the phosphate serves________.

A) to bind the sugars to their bases
B) as nucleotides
C) as a code
D) to hold the molecular backbone together

Question 42

What is the ratio of fatty acids to glycerol in triglycerides (neutral fats)?

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

Question 43

If atom X has an atomic number of 74 it would have which of the following?

A) 74 protons
B) 37 protons and 37 neutrons
C) 37 electrons
D) 37 protons and 37 electrons

Question 44

Atom X has 17 protons. How many electrons are in its valence shell (outermost energy level)?

A) 3
B) 10
C) 7
D) 5

Question 45

You notice that you cannot read your book through a test tube of patient fluid held against the print, making it so blurred as to be unreadable. There is no precipitant in the bottom of thebeaker, though it has been sitting for several days in a rack. What type of liquid is this?

A) suspension
B) mixture
C) solution
D) colloid

Question 46

Select the most correct statement regarding nucleic acids.

A) Three forms exist: DNA, RNA, and tDNA.
B) RNA is a long, single-stranded molecule made up of the bases A, T, G, and C.
C) DNA is a long, double-stranded molecule made up of A, T, G, and C bases.
D) tDNA is considered a "molecular slave" of DNA during protein synthesis.

Question 47

The four elements that make up about 96% of body weight are ________.

A) nitrogen, hydrogen, calcium, sodium
B) sodium, potassium, hydrogen, oxygen
C) carbon, oxygen, hydrogen, nitrogen
D) carbon, oxygen, phosphorus, calcium

Question 48

Amino acids joining together to make a peptide is a good example of a(n) ________ reaction.

A) synthesis
B) reversible
C) exchange
D) decomposition

Question 49

________ is fat soluble, produced in the skin on exposure to UV radiation, and necessary for normal bone growth and function.

A) Vitamin K
B) Cortisol
C) Vitamin D
D) Vitamin A

Question 50

Which of the following does not describe uses for the ATP molecule?

A) pigment structure
B) transport across membranes
C) chemical work
D) mechanical work

Question 51

An atom with 3 electrons in its outermost (valence) shell may have a total of ________ electrons altogether.

A) 13
B) 8
C) 17
D) 3

Question 52

Select the correct statement about isotopes.

A) All the isotopes of an element are radioactive.
B) Isotopes of the same element have the same atomic number but differ in their mass number.
C) Isotopes occur only in the heavier elements.
D) All the isotopes of an element have the same number of neutrons but differing numbers of electrons.

Question 53

A high fever causes an enzyme to lose its three dimensional structure and function. Which bonds are broken when a protein denatures?

A) ionic bonds
B) non-polar covalent bonds
C) polar covalent bonds
D) hydrogen bonds

Question 54

What does the formula C6H 12O6 mean?

A) There are, 6 carbon, 12 hydrogen, and 6 oxygen atoms.
B) There are 6 calcium, 12 hydrogen, and 6 oxygen atoms.
C) The molecular weight is 24.
D) The substance is a colloid.

Question 55

Which of the following is an example of a suspension?

A) blood
B) cytosol
C) rubbing alcohol
D) salt water

Question 56

Sucrose is a________.

A) triglyceride
B) monosaccharide
C) disaccharide
D) polysaccharide

Question 57

What is a dipole?

A) a type of reaction
B) a type of bond
C) a polar molecule
D) an organic molecule

Question 58

The chemical symbol O= O means ________.

A) the atoms are double bonded
B) both atoms are bonded and have zero electrons in the outer orbit
C) this is an ionic bond with two shared electrons
D) zero equals zero

Question 59

Which property of water is demonstrated when we sweat?

A) cushioning
B) high heat of vaporization
C) reactivity
D) high heat capacity
E) polar solvent properties

Question 60

Which of the following is not considered a factor in influencing a reaction rate?

A) time
B) particle size
C) concentration of reactants
D) temperature

Question 61

Lithium has an atomic number of 3. How many electrons are there in the outermost (valence)shell?

A) three
B) one
C) zero
D) two

Question 62

How many phosphates would AMP have attached to it?

A) two
B) none
C) one
D) three

Question 63

Phospholipids make up most of the lipid part of the cell membrane. Since water exists on both the outside and inside of a cell, which of the following phospholipid arrangements makes the most sense?

A) two back-t o-back phospholipid layers with the polar heads facing out on both sides
B) a single layer of phospholipids with the polar heads facing inside the cell
C) a single layer of phospholipids with the polar heads facing outside the cell
D) two back-t o-back phospholipid layers with the non-polar tails facing out on both sides

Question 64

Salivary amylase is an enzyme produced by the salivary glands that breaks downcarbohydrates. What will happen to this enzyme as it follows the food into the stomach where the pH drops to 2.5?

A) The enzyme will continue to function as it remains unchanged in chemical reactions.
B) The enzyme will assume an alternate form and catalyze additional reactions.
C) The enzyme will denature and become inactive.
D) The enzyme will denature but retain its function.

Question 65

How can phospholipids form a film when mixed in water?

Question 66

Tendons are strong, rope-like structures that connect skeletal muscle to bone. Which of the following proteins would provide strength to a tendon?

A) collagen
B) act in
C) molecular chaperone
D) albumin

Question 67

ATP · ADP + Pi is an example of a(n) ________ reaction.

A) reversible
B) decomposition
C) exchange
D) synthesis

Question 68

Which of the following is chemically inert (unreactive)?

A) sodium (atomic number 11)
B) oxygen (atomic number 8)
C) neon (atomic number 10)
D) carbon (atomic number 6)

Question 69

An atom with an atomic number of 10 and a mass number of 24 would have________.

A) 14 neutrons
B) 10 neutrons
C) 14 electrons
D) 24 protons

Question 70

An acid with a pH of 6 has________ hydrogen ions than pure water.

A) 10-fold fewer
B) 100-fold more
C) 100-fold fewer
D) 10-fold more

Question 71

What happens when globular proteins are denatured?

Question 72

Forming glycogen as energy storage in the liver is an example of ________.

A) exergonic
B) anabolism
C) oxidation
D) catabolism

Question 73

Describe the factors that affect chemical reaction rates.

Question 74

With a family history of cardiovascular disease, which toast spread would be considered the most "heart healthy?"

A) butter containing butterfat
B) olive oil
C) margarine containing trans fats
D) lard (pig fat)

Question 75

Explain the difference between potential and kinetic energy.

Question 76

When frying an egg, the protein albumin denatures and maintains only its________ structure.

A) quaternary
B) secondary
C) prima ry
D) tertiary

Question 77

Which of the following is incorrectly matched?

A) eicosanoid; triglyceride
B) nucleotide; nucleic acid
C) amino acid; protein
D) monosaccharide; carbohydrate

Question 78

Starch is the stored carbohydrate in plants, while ________ is the stored carbohydrate in animals.

A) glucose
B) triglyceride
C) cellulose
D) glycogen

Question 79

When DNA is replicated, it is necessary for the two strands to "unzip" temporarily. Choose which bonding type is most appropriate for holding the strands together in this way.

A) polar covalent bonding
B) non-polar covalent bonding
C) hydrogen bonding
D) ionic bonding

Question 80

What advantages does ATP have in being the energy currency molecule?