Deck 2: The Chemistry of Biology

Question 1

The valence number is the _______.

A) atomic weight
B) number of electrons in the innermost orbital
C) number of neutrons
D) number of protons
E) number of electrons in the outermost orbital

Answer 1

number of electrons in the outermost orbital

Question 2

The electrons of an atom are _______.

A) found in the nucleus
B) used to determine atomic number
C) positively charged
D) moving in pathways called orbitals
E) always equal to the number of neutrons in an atom

Answer 2

moving in pathways called orbitals

Question 3

The electrons of an atom are _______.

A) always equal to the number of protons
B) used to determine the atomic number
C) carrying a positive charge
D) always in full orbitals
E) used to determine the atomic weight

Answer 3

always equal to the number of protons

Question 4

Two or more atoms bonded together are called a(n) ______.

A) electrolyte
B) molecule
C) ion
D) element
E) isotope

Question 5

$\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}+\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6} \rightarrow \mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}+\mathrm{H}_{2} \mathrm{O}$ represents _______.

A) a decomposition reaction
B) the formation of a polysaccharide
C) a denaturation reaction
D) a dehydration synthesis
E) the formation of a peptide bond

Question 6

A capillary tube is used to acquire a small blood sample for CBC (complete blood count) analysis. Suction is not required to transfer the blood from the ?ngertip prick to the tube in part due to _______.

A) covalent bonding between the water molecules
B) cohesive forces between the glass particles of the tube and the water molecules
C) adhesive forces between the water molecules and the glass particles of the tube
D) ionic bonding between the water molecules

Question 7

Protons and neutrons make up the atom's central core, which is referred to as its ______.

A) valence number
B) nucleus
C) isotope
D) center of gravity

Question 8

Polar molecules are composed of covalently bonded _______.

A) ions
B) atoms of identical electronegativity
C) identical atoms
D) atoms of different electronegativity
E) carbon atoms

Question 9

Electrons that participate in chemical bonding are typically located closest to the nucleus.

Question 10

What is the maximum number of electrons in the ?rst energy shell of an atom?

A) 2
B) 4
C) 8
D) 18
E) 32

Question 11

Anything that occupies space and has mass is called ______.

A) matter
B) living
C) energy
D) atomic
E) space

Question 12

All of the following pertain to the atom Carbon-14 except it _______.

A) has 6 electrons
B) is an isotope of carbon
C) has 14 neutrons
D) has 6 protons

Question 13

What would be the valence number of electrons in the sulfur (S) atom? Its atomic number is 16.

A) 2
B) 6
C) 8
D) 16
E) 32

Question 14

Substances that release ions when dissolved in water and conduct electricity are ______.

A) covalent
B) nonpolar
C) solvents
D) electrolytes
E) electrons

Question 15

Polar molecules _______.

A) have an unequal charge distribution
B) always contain carbon
C) always involve oxygen
D) have an equal charge distribution
E) are insoluble in water

Question 16

What is the maximum number of electrons in the second energy shell of an atom?

A) 2
B) 4
C) 8
D) 18
E) 32

Question 17

An atom has gained an electron; it has been ______.

A) deionized
B) oxidized
C) reduced
D) neutralized
E) ionized

Question 18

Covalent bonds _______.

A) result from gaining electrons
B) result from losing electrons
C) are always nonpolar
D) result from sharing electrons
E) are always polar

Question 19

The subatomic particles that surround the nucleus are the ______.

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

Question 20

Organic chemicals always have a basic framework of the element _____ bonded to other atoms.

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

Question 21

Burning coal produces sulfur dioxide in the atmosphere. When combined with rain that falls into bodies of water, this leads to _______.

A) an increase in pH level of the water
B) a greater concentration of OH- ions in the water
C) a decrease in the pH level of the water
D) no change in the pH level of the water

Question 22

Ionic compounds _______.

A) are hydrophilic
B) are basic in solution
C) are hydrophobic
D) always form salts in solution
E) are acidic in solution

Question 23

Which of the following represents a reversible reaction?

A) AB + XY ? AY + XB
B) A + B ?AB
C) AB ? A + B
D) AB + XY ? AY + XB

Question 24

One technique for staining bacteria for viewing under the microscope is called the Gram stain. In this technique, alcohol is used as a decolorizer because it degrades the outer membrane found in some bacteria. What chemical component of the cell does alcohol affect?

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

Question 25

Polar molecules have more reactivity compared to nonpolar molecules.

Question 26

In the cell cytoplasm, molecules of ATP are a ______.

A) solute
B) solvent

Question 27

Cations are _______.

A) atoms that have gained neutrons
B) charged subatomic particles
C) atoms that have gained electrons
D) atoms without protons
E) capable of forming ionic bonds with anions

Question 28

The concentration of a solution expresses the amount of solvent present.

Question 29

Which of the following represents a synthesis reaction?

A) AB + XY ?AY + XB
B) AB + XY ? AY + XB
C) AB ? A + B
D) A + B ? AB

Question 30

If solution A has a lower pH compared to solution B, then solution A is more acidic than solution B.

Question 31

Compared to a solution of pH 9, a solution of pH 7 is _______.

A) 2 times more acidic
B) 20 times more acidic
C) 100 times more basic
D) 20 times more basic
E) 100 times more acidic

Question 32

The important solvent associated with living things is ______.

A) ethyl alcohol
B) benzene
C) water
D) sodium chloride
E) carbon dioxide

Question 33

Water molecules are nonpolar molecules.

Question 34

A covalent bond is formed between an anion and a cation.

Question 35

Hydrogen bonds _______.

A) result from attractive forces between molecules with polar covalent bonds
B) result from attractive forces between molecules with polar ionic bonds
C) are the strongest bonds between molecules
D) result from attractive forces between molecules with nonpolar ionic bonds
E) result from attractive forces between molecules with nonpolar covalent bonds

Question 36

Ionic bonds _______.

A) always involve carbon
B) result from transferring electrons
C) result from sharing electrons
D) result from like charge attraction
E) are the weakest chemical bonds

Question 37

Compared to a solution of pH 9, a solution of pH 7 _______.

A) has a higher pH
B) has no OH- ions
C) is more basic
D) has more H+ ions

Question 38

What type of bond is formed by dehydration synthesis between two amino acids?

A) Glycosidic
B) Ester
C) Phosphate
D) Disul?de
E) Peptide

Question 39

Atoms that gain or lose electrons become charged particles called ______.

A) cations
B) anions
C) isotopes
D) ions

Question 40

A reaction where an electron is lost is called ______.

A) oxidation
B) dissolution
C) decomposition
D) ionization
E) reduction

Question 41

An example of an amphipathic molecule found in living cells is ______.

A) phospholipid
B) ATP
C) nucleic acid
D) glucose
E) protein

Question 42

The purine ______ always hydrogen bonds with the pyrimidine ______ in double-stranded DNA.

A) guanine; cytosine
B) cytosine; guanine
C) adenine; guanine
D) thymine; guanine

Question 43

All of the following are polysaccharides except ______.

A) cellulose in certain cell walls
B) agar used to make solid culture media
C) sterols in cell membranes
D) dextran in some bacterial slime layers
E) a cell's glycocalyx

Question 44

All of the following are lipids except ______.

A) triglyceride
B) wax
C) phospholipid
D) starch
E) cholesterol

Question 45

What part of a phospholipid comprises the hydrophobic tail?

A) Fatty acids
B) Hydroxyl
C) Glycerol
D) Phosphate
E) Alcohol

Question 46

The building blocks of an enzyme are ______.

A) nucleotides
B) phosphate, glycerol, and fatty acids
C) monosaccharides
D) glycerol and fatty acids
E) amino acids

Question 47

The only part of an amino acid that differs from other amino acids is its R group.

Question 48

A student forgot to label a beaker containing a DNA solution and a beaker containing a glucose solution. If chemical analysis was performed to identify the contents of each beaker, which of the following would be found in the beaker of DNA but not in the beaker with glucose?

A) Fatty acids
B) Hydrogen and oxygen atoms
C) Nitrogen and phosphorus
D) Carbon atoms
E) Amino acids

Question 49

Which of the following would have glycosidic bonds?

A) Triglycerides
B) Polysaccharides
C) ATP
D) Polypeptides
E) Monosaccharides

Question 50

In what way would life be different if the element carbon was absent?

A) There would be no inorganic compounds.
B) There would be no organic compounds.
C) Life would not exist in any shape or form.
D) The concept of pH would not exist.

Question 51

Which of the following functional groups is mismatched to the organic compound in which it is typically found?

A) Phosphate - carbohydrates
B) Sulfhydryl - proteins
C) Hydroxyl - alcohols
D) Amino - proteins
E) Carboxyl - fatty acids

Question 52

An amino acid contains all of the following except a/an ______.

A) carboxyl group
B) variable R group
C) amino group
D) ? carbon
E) phosphate

Question 53

The lipid group that is the major component of cell membranes is the ______.

A) steroids
B) prostaglandins
C) waxes
D) phospholipids
E) triglycerides

Question 54

Select the statement that most accurately re?ects the process of plant material digestion in humans.

A) It requires the action of enzymes called kinases.
B) It is linked to the digestion of glycogen.
C) It is a process that is dependent upon enzyme (cellulase) production by gut microbiota.
D) It is a very e?cient process the produces very little undigested material in feces.

Question 55

Starch is the primary storage food for all of the following except ______.

A) animals
B) algae
C) some fungi
D) green plants

Question 56

All of the following are monosaccharides except ______.

A) fructose
B) glucose
C) deoxyribose
D) glycogen

Question 57

Most biochemical macromolecules are polymers, which are chains of ______.

A) repeating carbohydrates
B) hydrophobic molecules
C) electrolytic molecules
D) hydrogen bonds
E) repeating monomers

Question 58

All proteins are enzymes.

Question 59

The lipid group that serves as energy storage molecules is the ______.

A) phospholipids
B) steroids
C) waxes
D) prostaglandins
E) triglycerides

Question 60

A fat is called _______ if all carbons of the fatty acid chain are single-bonded to 2 other carbons and 2 hydrogens.

A) monounsaturated
B) saturated
C) unsaturated
D) polyunsaturated

Question 61

Purines and pyrimidines are components in the building block units of all ______.

A) amino acids
B) carbohydrates
C) enzymes
D) nucleic acids
E) polysaccharides

Question 62

The alpha (?) helix is a type of _____ protein structure.

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

Question 63

Which of the following is not a pyrimidine?

A) Adenine
B) Cytosine
C) Thymine
D) Uracil

Question 64

Which of the following is not true about enzymes?

A) Enzymes participate in the cell's chemical reactions.
B) Enzymes are found in all cells.
C) Enzymes are catalysts.
D) Enzymes have high-energy bonds between phosphates.
E) Enzymes can be denaturated by heat and other agents.

Question 65

All cells contain _______.

A) mitochondria to generate ATP
B) ribosomes for protein synthesis
C) organelles for compartmentalization
D) cell walls made of cellulose
E) uracil in their DNA

Question 66

One nucleotide contains one _______.

A) phosphate
B) pentose sugar
C) nitrogen base
D) All of the choices are correct.

Question 67

A culture of an organism believed to cause intestinal symptoms is viewed under the microscope, and the microbiologist observes a cell membrane, ?agella, mitochondria, and some dark unrecognizable structures within each cell. The microbiologist notes that the cells are eukaryotic because _______.

A) only eukaryotic cells have mitochondria
B) only eukaryotic cells have ?agella
C) only eukaryotic cells have a cell membrane
D) the dark structures must be the cell nuclei

Question 68

Characteristics shared by all cells include _______.

A) a membrane serving as a cell boundary
B) the possession of genetic information
C) the presence of cellular ?uid
D) All of the choices are correct.

Question 69

NASA has published a list of criteria for identifying fossil bacteria in samples from Mars, as part of a search for evidence of life. Which of the following is good evidence for the presence of bacterial cells?

A) Three-dimensional organization of cells in a starburst pattern
B) Absence of carbon in the material
C) Cell size of 0.5 to 2 microns
D) No evidence of water in the surrounding mineral

Question 70

Which of the following is a correct description of a component of the ATP molecule?

A) Nitrogenous base: alanine
B) Sugar: deoxyribose
C) High energy bond: peptide bond
D) High energy bond: glycosidic bond
E) Sugar: ribose

Question 71

ATP differs from the nucleotides found in DNA in the _______.

A) use of adenosine instead of adenine
B) use of phosphorus in the nitrogenous base portion of the molecule
C) sugar portion of the molecule
D) use of phosphate instead of sulfate in the backbone
E) use of uracil in the nitrogenous base portion of the molecule

Question 72

A new organism was identi?ed that contained arsenic in place of phosphate in its DNA double helix structure. Based upon this information alone, it can be determined that this change will greatly alter the information encoded by this genetic material.

Question 73

Which pertains to DNA but not to RNA?

A) Contains nucleotides
B) Contains adenine
C) Contains ribose
D) Contains thymine
E) Contains uracil

Question 74

The most important outcome of polypeptide intrachain bonding and folding is the unique shape of the protein.

Question 75

Which of the following statements is incorrect regarding protein structure?

A) Proteins, such as antibodies that are comprised of multiple polypeptide chains, have quaternary structure.
B) The folding of a protein to form its active site creates its tertiary structure.
C) Beta-pleated sheets are a type of protein secondary structure.
D) The interaction between various R groups of amino acids determines the primary structure of a protein.

Question 76

ATP is best described as _______.

A) an electron carrier
B) a double helix
C) the energy molecule of cells
D) an enzyme

Question 77

Nucleic acids have primary, secondary, tertiary, and quaternary levels of organization.