Deck 2: The Chemistry of Biology

Question 1

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

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

Answer 1

A

Question 2

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

Answer 2

False

Question 3

C₆H₁₂O₆ + C₆H₁₂O₆ $\rarr$ C₁₂ H₂₂O₁₁ + H₂O represents

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

Answer 3

a dehydration synthesis.

Question 4

The electrons of an atom are

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

Question 5

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

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

Question 6

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

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

Question 7

The electrons of an atom are

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

Question 8

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 9

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

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

Question 10

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 fingertip 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) ionic bonding between the water molecules.
D) adhesive forces between the water molecules and the glass particles of the tube.

Question 11

The subatomic particles that surround the nucleus are the ______.

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

Question 12

Polar molecules are composed of covalently bonded

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

Question 13

Polar molecules

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

Question 14

Covalent bonds

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

Question 15

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

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

Question 16

The valence number is the

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

Question 17

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

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

Question 18

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

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

Question 19

Anything that occupies space and has mass is called ______.

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

Question 20

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 21

The important solvent associated with living things is ______.

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

Question 22

Hydrogen bonds

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

Question 23

Ionic compounds

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

Question 24

Ionic bonds

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

Question 25

Polar molecules have more reactivity compared to nonpolar molecules.

Question 26

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

Question 27

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

Question 28

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

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

Question 29

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

Question 30

Which of the following represents a reversible reaction?

A) A + B $\rarr$ AB
B) AB $\rarr$ A + B
C) AB + XY $\harr$ AY + XB
D) AB + XY $\rarr$ AY + XB

Question 31

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

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

Question 32

Cations are

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

Question 33

A reaction where an electron is lost is called ______.

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

Question 34

Which of the following represents a synthesis reaction?

A) AB $\rarr$ A + B
B) A + B $\rarr$ AB
C) AB + XY $\rarr$ AY + XB
D) AB + XY $\harr$ AY + XB

Question 35

Water molecules are nonpolar molecules.

Question 36

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

A) solute
B) solvent

Question 37

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

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

Question 38

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

A) Ester
B) Peptide
C) Phosphate
D) Disulfide
E) Glycosidic

Question 39

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

Question 40

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

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

Question 41

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

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

Question 42

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

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

Question 43

All of the following are polysaccharides except

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

Question 44

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

Question 45

What part of a phospholipid comprises the hydrophobic tail?

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

Question 46

All proteins are enzymes.

Question 47

Select the statement that most accurately reflects 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 efficient process the produces very little undigested material in feces.

Question 48

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

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

Question 49

All of the following are lipids except ______.

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

Question 50

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

A) phosphate
B) $\alpha$ carbon
C) carboxyl group
D) variable R group
E) amino group

Question 51

Which of the following would have glycosidic bonds?

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

Question 52

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) unsaturated
C) polyunsaturated
D) saturated

Question 53

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

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

Question 54

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

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

Question 55

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

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

Question 56

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

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

Question 57

All of the following are monosaccharides except ______.

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

Question 58

The building blocks of an enzyme are ______.

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

Question 59

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

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

Question 60

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

Question 61

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

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

Question 62

All cells contain

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

Question 63

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) No evidence of water in the surrounding mineral
C) Cell size of 0.5 to 2 microns
D) Absence of carbon in the material

Question 64

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

Question 65

A new organism was identified 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 66

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

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

Question 67

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

Question 68

ATP is best described as

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

Question 69

Which pertains to DNA but not to RNA?

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

Question 70

One nucleotide contains one

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

Question 71

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

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

Question 72

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 sequence of nucleotides determines the primary structure of a protein.

Question 73

Which of the following is not a pyrimidine?

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

Question 74

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

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

Question 75

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 fluid.
D) All of the choices are correct.

Question 76

Which of the following is not true about enzymes?

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

Question 77

ATP differs from the nucleotides found in DNA in the

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