Deck 2: Chemistry Comes Alive

Question 1

Triglycerides are a poor source of stored energy.

Answer 1

False

Question 2

Chemical properties are determined primarily by neutrons.

Answer 2

False

Question 3

Glucose is an example of a monosaccharide.

Answer 3

True

Question 4

Buffers resist abrupt and large changes in the pH of body fluids by releasing or binding ions.

Question 5

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

Question 6

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

Question 7

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

Question 8

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

Question 9

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

Question 10

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

Question 11

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

Question 12

A charged particle is generally called an ion or electrolyte.

Question 13

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

Question 14

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.

Question 15

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

Question 16

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

Question 17

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

Question 18

The sharing of electrons in covalent bonds makes them stronger than ionic and hydrogen bonds.

Question 19

All organic compounds contain carbon except CO₂ and CO.

Question 20

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

Question 21

The single most abundant protein in the body is _ _.

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

Question 22

Which of the following statements is FALSE?

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

Question 23

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

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

Question 24

The genetic information is coded in DNA by the .

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

Question 25

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

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

Question 26

Which of the following does NOT describe enzymes?

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

Question 27

Which of the following would be regarded as an organic molecule?

A) CO₂
B) CH4
C) H₂O
D) NaOH

Question 28

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

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

Question 29

Which of the following does NOT characterize proteins?

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

Question 30

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

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

Question 31

The basic structural material of the body consists of .

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

Question 32

What structural level is represented by the sequence of amino acids in a polypeptide chain?

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

Question 33

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

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

Question 34

In general, the lipids that we refer to as oils at room temperature have _ .

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

Question 35

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

Question 36

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

A) forming a smaller molecule
B) the release of energy
C) degradation
D) the consumption of energy

Question 37

Which statement about enzymes is FALSE?

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

Question 38

Carbohydrates and proteins are built up from their basic building blocks by the .

A) removal of a carbon atom between each two units
B) removal of a water molecule between each two units
C) addition of a water molecule between each two units
D) addition of a carbon atom between each two units

Question 39

Salts are always .

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

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

Question 41

The chemical symbol O=O means _ .

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

Question 42

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

A) mechanical work
B) chemical work
C) transport down their concentration gradient
D) pigment structure

Question 43

Select which reactions will usually be irreversible regarding chemical equilibrium in human bodies.

A) ADP + Pi to make ATP
B) glucose to CO₂ and H₂O
C) H₂O + CO₂ to make H₂CO₃
D) glucose molecules joined to make glycogen

Question 44

Choose the answer that best describes HCO₃-.

A) a weak acid
B) a proton donor
C) common in the liver
D) a bicarbonate ion

Question 45

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) hydrogen bonds
C) non-polar covalent bonds
D) polar covalent bonds

Question 46

Select the most correct statement regarding nucleic acids.

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

Question 47

Which type of proteins can function as chemical messengers or as receptors in the plasma membrane?

A) enzyme
B) communication
C) defensive
D) transport

Question 48

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

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

Question 49

What happens in redox reactions?

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

Question 50

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 the beaker, 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 51

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

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

Question 52

If the atomic mass of an element is 14 and the atomic number is 6, which of the following would describe this element?

A) isotope
B) atom
C) neutral
D) ion

Question 53

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

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

Question 54

What is a cation?

A) an atom that loses one or more electrons and acquires a net positive charge
B) an atom that shares its valence electrons
C) a molecule that has both positive and negative charges
D) an atom that gains one or more electrons and acquires a net negative charge

Question 55

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

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

Question 56

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

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

Question 57

Which of the following is an example of a suspension?

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

Question 58

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

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

Question 59

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

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

Question 60

What does the formula C6H12O6 mean?

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

Question 61

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

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

Question 62

Which of the following is incorrectly matched?

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

Question 63

In a DNA molecule, the phosphate serves .

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

Question 64

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

A) albumin
B) molecular chaperone
C) collagen
D) actin

Question 65

Salivary amylase is an enzyme produced by the salivary glands that breaks down carbohydrates. 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 denature but retain its function.
B) The enzyme will denature and become inactive.
C) The enzyme will continue to function as it remains unchanged in chemical reactions.
D) The enzyme will assume an alternate form and catalyze additional reactions.

Question 66

Which property of water is demonstrated when we sweat?

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

Question 67

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

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

Question 68

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

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

Question 69

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

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

Question 70

Starch is a .

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

Question 71

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

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

Question 72

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

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

Question 73

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

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

Question 74

Which of the following is chemically inert (unreactive)?

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

Question 75

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

Question 76

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

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

Question 77

A patient is hyperventilating. The "blowing off" of excessive carbon dioxide causes a decrease in blood H+ concentration. How can the carbonic acid-bicarbonate buffer system function to correct this imbalance? CO₂ + H₂O -H₂CO₃ -H+ + HCO₃-

A) HCO₃- binds with H+ to form H₂CO₃ and lower pH
B) H₂CO₃ dissociates to form more H+ and raise pH
C) H₂CO₃ dissociates to form more H+ and lower pH
D) HCO₃- binds with H+ to form H₂CO₃ and raise pH

Question 78

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

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

Question 79

How many phosphates would ADP have attached to it?

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

Question 80

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