Deck 15: The Chemistry of Life

Question 1

Which is NOT an organic functional group characteristic of carbohydrates?

A) -CHO
B) -OH
C) -C-C-
D) -NH₂

Answer 1

-NH₂

Question 2

Which oil contains a higher percentage of saturated fatty acid than the others?

A) olive oil
B) coconut oil
C) corn oil
D) All oils contain less saturated fatty acid than unsaturated fatty acid.

Answer 2

coconut oil

Question 3

Which is not true about proteins?

A) polypeptides
B) condensation polymers
C) repeating units are amino acids
D) constituent of genes

Answer 3

constituent of genes

Question 4

For the peptide shown, which number indicates the peptide bond?

A) a
B) b
C) c
D) d

Question 5

The hydrocarbon end of a detergent molecule is

A) hydrophilic.
B) hydrophobic.
C) possibly ionic.
D) likely to contain an oxygen or sulfur atom.

Question 6

If four amino acids are all different, what is the number of peptides possible?

A) 4
B) 8
C) 10
D) 24

Question 7

Which is not true about enantiomers?

A) they have "handedness"
B) nonsuperimposable mirror images
C) symmetrical, with superimposable mirror images
D) rotate plane polarized light in opposite directions

Question 8

The energy reservoir in animals is

A) starch.
B) dextrin.
C) glucose.
D) glycogen.

Question 9

Which is not true about carbohydrates?

A) can be broken down into smaller carbohydrate units
B) condensation polymers
C) form an essential part of the energy cycle for living things
D) All these are true.

Question 10

A condition of lactose intolerance means an individual

A) has insufficient lactose in the diet.
B) must have a diet high in milk products.
C) has a stomach pH greater than seven.
D) lacks the enzyme lactase.

Question 11

Which of the following has a caloric value approximately equal to that of proteins?

A) lactose
B) aspartame
C) saccharin
D) sucrose

Question 12

Which of the following molecules has a chiral center?

A)
B)
C)
D)

Question 13

Which term describes the general function of an enzyme?

A) substrate
B) intermediate
C) catalyst
D) oxidant

Question 14

Which of the following is not a steroid?

A) cholesterol
B) testosterone
C) carnauba wax
D) estrone

Question 15

Insulin, a hormone that is essential to controlling the concentration of glucose in the blood, is a

A) a protein.
B) fat.
C) carbohydrate.
D) lipid.

Question 16

Amino acids that the body cannot synthesize from other molecules are called

A) necessary amino acids.
B) essential amino acids.
C) natural amino acids.
D) prized amino acids.

Question 17

Which object/objects are not chiral?

A) your hands
B) helical sea shells
C) spoons
D) golf clubs

Question 18

Chemically, fats and oils are

A) esters.
B) amides.
C) alcohols.
D) ketones.

Question 19

Which of the following is not true about sucrose?

A) a disaccharide
B) found in sugar beets
C) made up of only glucose units
D) converted into honey by an enzyme

Question 20

The structure of a tripeptide is Ala-Ser-Aly. What are the expected elements present in the tripeptide?

A) C, H, N, O
B) C, H
C) C, H, N
D) C, H, O

Question 21

Which of the following is not true about DNA?

A) It is a polymer.
B) Base pairs are formed between A and T and G and C.
C) It is single stranded.
D) Deoxyribose is the sugar in DNA.

Question 22

Which of the following represents the composition and structure of a nucleotide? [P = phosphate group, S = sugar, B = nitrogenous base]

A) P-S-B
B) S-B
C) P-B
D) S-P-B

Question 23

Lactose is a disaccharide found in

A) sugar beets.
B) sugar cane.
C) starch.
D) milk.

Question 24

Compounds with the ring structure shown below are

A) nucleic acids
B) steroids
C) polysaccharides
D) nucleotides

Question 25

The folded structure of polypeptide chains held in place by -S-S- bonds is

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

Question 26

When monosaccharides such as D-glucose are joined to form the polysaccharide starch, at each bond between two monosaccharides,

A) a water molecule hydrogen bonds the two monomers together.
B) there is a peptide bond.
C) there is a hydrated carbon atom.
D) a water molecule is split out.

Question 27

The monomers in proteins are

A) monosaccharides.
B) amino acids.
C) nucleic acids.
D) all optically active.

Question 28

The process in which mRNA is made from DNA is called

A) transcription.
B) translation.
C) replication.
D) recombination.

Question 29

Secondary structures of proteins are achieved by

A) strong covalent bonds.
B) ionic bonds.
C) London forces.
D) hydrogen bonds.

Question 30

Which base is not common to both DNA and RNA?

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

Question 31

How many natural occurring amino acids are known?

A) 20
B) 70
C) hundreds
D) thousands

Question 32

The naturally occurring amino acids found in proteins

A) are all chiral.
B) are a mixture of enantiomers.
C) all optically active.
D) contain an amine and a carboxylic acid group.

Question 33

Collagen found in bones, tendons, teeth, and cartilage is

A) a fibrous protein.
B) a sheetlike protein.
C) 100% glycine.
D) a globular protein.

Question 34

Hydrolysis of sucrose yields

A) "D-glucose only."
B) "D-glucose and D-fructose."
C) " $\beta$ -D-glucose and $\alpha$ -D-glucose."
D) "D-galactose and D-glucose."

Question 35

The general type of chemical process which constitutes digestion is

A) hydration
B) combustion.
C) hydrolysis.
D) oxidation.

Question 36

The primary structure of proteins is

A) the amino acid sequence of amino acids in the polypeptide chain.
B) the helical structure.
C) the sheetlike structure.
D) the preferred conformation of a given protein.

Question 37

Amino acid monomers are joined to make a polypeptide chain by

A) an acid-base reaction.
B) formation of a peptide bond.
C) splitting out a water molecule.
D) all of the above choices

Question 38

Polysaccharides, proteins, and nucleic acids are all

A) C, H, and O compounds only.
B) inorganic compounds.
C) polymers.
D) helical structures.

Question 39

If a molecule of glycine bonds to a molecule of alanine, how many dipeptides can be made?

A) one
B) two
C) three
D) more than three

Question 40

Plant starches are amylose and amylopectin. Amylose differs from amylopectin in that amylose is

A) a straight chain structure.
B) insoluble in hot water.
C) a sweetener.
D) composed of only galactose.

Question 41

The role of mRNA in natural protein synthesis is to

A) give the coded message to DNA of what protein to produce.
B) carry the amino acids to the cell's nucleus where protein synthesis occurs.
C) activate the nerve center to the need of a certain protein.
D) serve as a base pairing template for tRNA to assemble amino acids into protein.

Question 42

The purpose of ATP and compounds similar to ATP is to

A) be available to catalyze the combustion of glucose.
B) serve as template for molecular replication.
C) oxidize chlorophyll.
D) store energy in P-O bonds.

Question 43

The quaternary structure of proteins is

A) the direction of twisting of the helical structure.
B) the shape assumed by all chains in a protein.
C) a four-side protein structure.
D) how amino acids hydrogen bond to every fourth amino acid in a polypeptide chain.
E) structures containing four polypeptide chains.

Question 44

When one strand of DNA replicates, the strand

A) reproduces itself exactly.
B) produces its complement.
C) produces two strands of polynucleotide.
D) undergoes hydrolysis.

Question 45

The toughness of both skin and hair in contrast to other protein structures is due to

A) the strength of the carbon-carbon bond.
B) the percentage composition relative to the amino acid content.
C) cross-linkages such as the disulfide bond.
D) the presence of ether linkages between the amino acid units.

Question 46

Which polysaccharide is the most abundant organic molecule on earth?

A) cellulose
B) starch
C) amylose
D) glycogen

Question 47

Which is not a characteristic of soaps?

A) contain a long chain hydrophobic group
B) contain a polar group that interacts with water
C) sodium salts are very common
D) work well in either hard or soft water

Question 48

In recombinant DNA processes,

A) polynucleotides are synthesized from mononucleotides.
B) all of the genes are joined together.
C) genes (DNA) are cut, spliced, and recombined.
D) there is only the likelihood of the betterment of mankind.

Question 49

Which object/objects can be chiral?

A) proteins
B) an alanine molecule
C) pair of shoes
D) all of the above

Question 50

The secondary structure of DNA is

A) similar to that of globular protein.
B) a double helix.
C) a single strand of folded polynucleotide.
D) sheetlike.

Question 51

Which oil contains the highest percentage of monounsaturated fatty acids?

A) olive oil
B) coconut oil
C) canola oil
D) lard

Question 52

For the peptide shown, which is the N-terminal end?

A) a
B) b
C) c
D) d

Question 53

Which is not true about detergents?

A) The positive charged end is cationic.
B) The polar part is oil soluble.
C) The water soluble part is hydrophilic.
D) Work well in hard water.

Question 54

Base pairing between the two strands of DNA occurs by means of

A) hydrogen bonding.
B) coordinate covalent bonds.
C) ionic bonds.
D) disufide bonds.

Question 55

Enzymes combine with a substrate at active sites and thereby

A) lower the energy of activation for a reaction.
B) form a stable molecule between the enzyme and the substrate.
C) consume the substrate.
D) supply energy to a reaction.

Question 56

A nucleotide does not contain

A) a 5-carbon sugar
B) a phosphoric acid species.
C) a ringed compound with nitrogen atoms in the rings.
D) an amino acid.

Question 57

For making permanent hair waves it is necessary to break these bonds

A) ionic bonds.
B) disulfide bonds.
C) hydrogen bonds.
D) the sulfur hydrogen bonds.

Question 58

Which is not true about saponification?

A) a hydrolysis
B) soaps are products
C) a reaction of fatty acids
D) a strongly basic solution is required

Question 59

Substances with solubility properties similar to those of fats and oils (dissolve in nonpolar solvents) are

A) fatty acids.
B) bile salts.
C) lipids.
D) nucleic acids.

Question 60

Which mixture is racemic?

A) sand and sugar
B) sugar and protein
C) L-glucose and D-glucose
D) D-glucose and E-glucose

Question 61

Natural amino acids are L-amino acids and natural sugars are D-sugars.

Question 62

Hydrolysis of lactose yields

A) "D-glucose only."
B) "D-glucose and D-fructose."
C) " $\beta$ -D-glucose and $\alpha$ -D-glucose."
D) "D-galactose and D-glucose."

Question 63

In a hydrolysis reaction, a larger molecule is split into smaller molecules which is essentially the reverse of a condensation reaction.

Question 64

A $\beta$ -pleated sheet is a common tertiary structure of proteins.

Question 65

For questons 1-7, consider the molecular structure given in each question, then complete the statement with one of the following terms.
carbohydrate
protein
nucleic acid
lipid
The following structure would be classified as a ________________.

Question 66

The secondary structure of proteins is

A) the amino acid sequence of amino acids in the polypeptide chain.
B) the helical structure.
C) the sheetlike structure.
D) the preferred conformation of a given protein.

Question 67

For questons 1-7, consider the molecular structure given in each question, then complete the statement with one of the following terms.
carbohydrate
protein
nucleic acid
lipid
The following structure would be classified as a ________________.

Question 68

For questons 1-7, consider the molecular structure given in each question, then complete the statement with one of the following terms.
carbohydrate
protein
nucleic acid
lipid
The following structure would be classified as a ________________.

Question 69

The process in which mRNA is used to synthesize protein

A) transcription.
B) translation.
C) replication.
D) recombination.

Question 70

Which is not true about RNA?

A) It is a polymer.
B) Base pairs are formed between A and U and G and C.
C) It is single stranded.
D) Deoxyribose is the sugar in RNA.

Question 71

Emulsifying agents are used to stabilize water-in-oil and oil-in-water mixtures.

Question 72

Which base is common to RNA but not DNA?

A) guanine
B) uracil
C) adenine
D) cytosine

Question 73

Which of the following is not a lipid?

A) cholesterol
B) testosterone
C) oleic acid
D) hemoglobin

Question 74

Which artificial sugar has the highest sweetness rating?

A) sucrose
B) splenda
C) aspartame
D) saccharin

Question 75

Fats tend to be saturated compounds while oil are unsaturated.

Question 76

Consider the following substance found in over the counter analgesics. How many chiral centers are in this molecule?

A) 1
B) 2
C) 3
D) 4
E) There are no chiral centers in this molecule.

Question 77

For questons 1-7, consider the molecular structure given in each question, then complete the statement with one of the following terms.
carbohydrate
protein
nucleic acid
lipid
The following structure would be classified as a ________________.

Question 78

D-glucose is also known as blood sugar.

Question 79

Glucose and sucrose are two of the most common monosaccharides.

Question 80

Lipids are a class of compounds which are not soluble in water and contain a fused four ring structure.