Deck 15: The Chemistry of Life

Question 1

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

Answer 1

symmetrical, with superimposable mirror images

Question 2

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

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

Answer 2

24

Question 3

The hydrocarbon end of a detergent molecule is

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

Answer 3

hydrophobic

Question 4

Which is not true about carbohydrates?

A) all 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 5

Which molecule has a chiral center?

A)

B)

C)

D)

Question 6

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 7

Which term describes the general function of an enzyme?

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

Question 8

Which is NOT an organic functional group characteristic of carbohydrates?

A) -CHO
B) -OH
C) -C-C-
D) -NH₂

Question 9

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 10

Which object/objects are not chiral?

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

Question 11

Which is not a steroid?

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

Question 12

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 13

Which is not true about sucrose?

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

Question 14

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

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

Question 15

Chemically, fats and oils are

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

Question 16

For the peptide shown, which is the peptide bond?

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

Question 17

The energy reservoir in animals is

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

Question 18

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

Question 19

Which is not true about proteins?

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

Question 20

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 21

Lactose is a disaccharide found in

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

Question 22

The process in which mRNA is made from DNA is called

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

Question 23

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 24

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 25

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 26

The general type of chemical process which constitutes digestion is

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

Question 27

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 28

The most common monosaccharide is

A) starch
B) cellulose
C) fructose
D) D-glucose

Question 29

The monomers in proteins are

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

Question 30

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 31

Hydrolysis is

A) a water-splitting reaction
B) an oxidation
C) a reduction
D) required prior to a combustion

Question 32

Which 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 33

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

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

Question 34

How many natural amino acids are known?

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

Question 35

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

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

Question 36

Carbohydrates, proteins, and DNA are all

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

Question 37

Which base is not common to both DNA and RNA?

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

Question 38

Which is not D-glucose?

A) grape sugar
B) blood sugar
C) dextrose
D) galactose

Question 39

Compounds with the ring structure shown below are

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

Question 40

Amino acids in natural protein are

A) nitrogen free
B) a mixture of L-isomers and D-isomers
C) the L-isomers
D) the D-isomers

Question 41

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 42

The quaternary structure of proteins is

A) the direction of twisting of the helical structure
B) the aggregation of the tertiary or secondary structures
C) a four-side protein structure
D) how amino acids hydrogen bond to every fourth amino acid in a polypeptide chain

Question 43

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 44

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 45

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 46

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 47

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 48

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 49

What is the essential structural difference between vegetable oils and vegetable fats?

A) oils have more double bonds
B) oils contain no carbon
C) oils contain no oxygen
D) nothing

Question 50

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 51

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 52

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

A) hydrogen bonding
B) coordinate covalent bonds
C) ionic bonds
D) London forces

Question 53

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 54

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 55

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 56

Secondary structures of proteins are achieved by

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

Question 57

A label says a typical cold cream contains almond oil, rose water, lanolin and spermaceti oil.Which component is the emulsifier?

A) almond oil
B) rose water
C) lanolin
D) spemaceti oil

Question 58

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 59

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 60

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 61

Which artificial sugar has the highest sweetness rating?

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

Question 62

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 63

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 64

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 65

The process in which mRNA is used to synthesize protein

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

Question 66

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 67

Which base is common to RNA but not DNA?

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

Question 68

Which polysaccharide is the most abundant organic molecule on earth?

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

Question 69

Which oil contains the highest percentage of monounsaturated fatty acids?

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

Question 70

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

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

Question 71

Which object/objects can be chiral?

A) proteins
B) methane molecule
C) spoons
D) baseball bats

Question 72

Which is not a lipid?

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