Deck 23: Organic Polymers, natural and Synthetic

Question 1

Which of the following is a polysaccharide?

A) α-Glucose
B) Fructose
C) Cellulose
D) Sucrose
E) α-Maltose

Answer 1

Cellulose

Question 2

Glycine,H₂NCH₂COOH,can polymerize via a condensation reaction.What simple molecule is a byproduct of this polymerization reaction?

A) H₂
B) NH₃
C) N₂
D) H₂O
E) O₂

Answer 2

H₂O

Question 3

Which one of the following polymers is made by a condensation reaction?

A) Teflon
B) Poly(ethylene terephthalate)
C) Polyethylene
D) Polystyrene
E) Polyvinyl chloride

Answer 3

Poly(ethylene terephthalate)

Question 4

Using the acid dissociation constants for glycine (K_a1 = 4.6 × 10−³ and K_a2 = 2.5 × 10−¹⁰),calculate the [Z]/[C⁺] ratio at pH 1.00.(Z = Zwitterion,C⁺ = fully protonated cation)

A) 2.5 × 10−¹¹
B) 2.5 × 10−⁹
C) 4.6 × 10−⁴
D) 0.046
E) 22

Question 5

What is the monomer used to make the following polymer?

A)
B)
C)
D)
E)

Question 6

When a diamine reacts with a dicarboxylic acid,a ____ is formed?

A) polyamide
B) polyester
C) disaccharide
D) carbohydrate
E) saccharide

Question 7

The general formula of a carbohydrate is ____.

A) C_nH_2nO_n
B) C_nH_2n+2O_n
C) C_nH_2nO_2n
D) C_n(H₂O)_m
E) C_n(OH)_m

Question 8

Teflon is made from the addition reaction of ____.

A) C₂H₄
B) C₃H₆
C) CH₂CHCl
D) CH₂CHCN
E) C₂F₄

Question 9

Sucrose is commonly known as ____.

A) aspartame
B) Splenda
C) NutraSweet
D) saccharine
E) sugar

Question 10

The reaction between an amine and a carboxylic acid is a condensation.What small molecule is formed as a byproduct of this reaction?

A) H₂O
B) H₂
C) CO₂
D) O₂
E) CO

Question 11

Which of the following statements concerning cellulose is INCORRECT?

A) Humans lack the enzymes needed to catalyze the hydrolysis of cellulose.
B) Cellulose contains unbranched chains of roughly 50-300 glucose molecules.
C) The molecular structure of cellulose allows for hydrogen bonding between polymer chains.
D) The major industrial source of cellulose is wood.
E) In cellulose,the oxygen bridge between glucose units is in the beta position.

Question 12

The polymerization of 1,2-dichloroethylene,CHClCHCl,will yield which of the following polymers?

A)
B)
C)
D)
E)

Question 13

Polyacrylonitrile is an addition polymer made from the acrylonitrile monomer,CH₂CHCN.How many monomer units are in a polyacrylonitrile polymer that has a molar mass of 8.33 × 10⁴ g/mol?

A) 7.90 × 10²
B) 1.57 × 10³
C) 3.14 × 10³
D) 8.33 × 10⁴
E) 4.42 × 10⁶

Question 14

For an amino acid,proton transfer occurs from the carboxylic acid group to the amine group.The resulting species,which has both a +1 and a −1 charge,is called a(n)_____ .

A) amide
B) zwitterion
C) cation
D) anion
E) protein

Question 15

Which of the following statements concerning starch is INCORRECT?

A) Starch is a polysaccharide found in plants.
B) Starch is abundant in corn and potatoes.
C) Amylose comprises about 20% of starch and it is insoluble in water.
D) Amylopectin,a highly branched component of starch,is soluble in water.
E) Amylose is composed of α-glucose polymers;amylopectin is composed of β-glucose polymers.

Question 16

PVC is a stiff,rugged polymer made from the addition reaction of ____.

A) C₂H₄
B) C₃H₆
C) CH₂CHCl
D) CH₂CHCN
E) C₂F₄

Question 17

How many of the 20 common α-amino acids are considered "essential" (i.e. ,required by humans for protein construction).

A) 2
B) 5
C) 10
D) 13
E) 17

Question 18

Which amino acid contains no chiral carbon atoms?

A) Proline
B) Glutamine
C) Lysine
D) Glycine
E) Leucine

Question 19

Fructose is

A) commonly known as blood sugar.
B) a monosaccharide found in honey and fruit juices.
C) a disaccharide formed from two glucose molecules.
D) a polysaccharide formed from several hundred glucose molecules.
E) an enzyme that catalyzes the decomposition of glucose.

Question 20

Which of the following molecules will react with oxalic acid to produce a polymer with the following repeating unit?

A)
B)
C)
D)
E)

Question 21

Using the acid dissociation constants for alanine (K_a1 = 5.1 × 10−³ and K_a2 = 1.8 × 10−¹⁰),calculate the [Z]/[A−] ratio at pH 11.50.(Z = Zwitterion,A− = deprotonated anion)

A) 6.2 × 10−¹⁰
B) 5.1 × 101
C) 1.8 × 10−²
D) 4.6 × 10⁹
E) 1.6 × 10⁹

Question 22

How many different dipeptides can be made from the 20 common amino acids?

A) 20
B) 39
C) 40
D) 380
E) 400

Question 23

For serine (K_a1 = 6.5 × 10−³ and K_a2 = 6.2 × 10−¹⁰),at what pH does [Z] = [C⁺]?

A) 2.19
B) 4.79
C) 7.00
D) 9.21
E) 11.81

Question 24

How many tripeptides can be made from alanine,serine,and leucine,using each amino acid only once per tripeptide?

A) 3
B) 4
C) 6
D) 9
E) 27

Question 25

Using the acid dissociation constants for glycine (K_a1 = 4.6 × 10−³ and K_a2 = 2.5 × 10−¹⁰),calculate the [Z]/[C⁺] ratio at pH 8.00.(Z = Zwitterion,C⁺ = fully protonated cation)

A) 2.2 × 10−⁶
B) 6.6 × 10−⁴
C) 2.5 × 10−²
D) 4.0 × 10¹
E) 4.6 × 10⁵

Question 26

Amino acids polymerize in condensation reactions that result in the formation of an amide linkage (or peptide bond)between amino acid molecules.What is a possible dipeptide formed in the reaction of alanine with phenylalanine?

A)
B)
C)
D)
E) None of the above

Question 27

What is the correct structure of alanylserine? Alanine has a CH₃ functional group and serine has a CH₂OH functional group.

A)
B)
C)
D)
E)

Question 28

How many different tripeptides can be made from the 20 common amino acids?

A) 60
B) 400
C) 8.0 × 10³
D) 1.6 × 10⁵
E) 3.5 × 10⁹

Question 29

On complete hydrolysis,a polypeptide gives two glycine,one alanine,one valine,and one serine residue.Partial hydrolysis gives the following fragments: Gly-Ser,Val-Gly,Ser-Val,and Ala-Gly.What is the primary structure of the polypeptide?

A) Ala-Gly-Gly-Val-Ser
B) Gly-Ser-Val-Gly-Ala
C) Ser-Val-Gly-Ala-Gly
D) Ala-Gly-Ser-Val-Gly
E) Val-Gly-Ser-Val-Ala

Question 30

Using the acid dissociation constants for glycine (K_a1 = 4.6 × 10−³ and K_a2 = 2.5 × 10−¹⁰),calculate the [Z]/[A−] ratio at pH 7.00.(Z = Zwitterion,A− = deprotonated anion)

A) 2.2 × 10−⁵
B) 2.5 × 10−³
C) 4.0 × 10²
D) 4.6 × 10⁴
E) 1.8 × 10⁷

Question 31

What is the correct structure of serylglycine (Ser-Gly)? Serine has a CH₂OH functional group and glycine is functionalized with an H atom.

A)
B)
C)
D)
E)

Question 32

When glycine and alanine combine to form a dipeptide,how many structural isomers are possible?

A) No structural isomers are possible.
B) Two structural isomers are possible.
C) Three structural isomers are possible.
D) Four structural isomers are possible.
E) Six structural isomers are possible.

Question 33

For serine (K_a1 = 6.5 × 10−³ and K_a2 = 6.2 × 10−¹⁰),at what pH does [Z] = [A−]?

A) 2.19
B) 4.79
C) 7.00
D) 9.21
E) 11.81

Question 34

The pH at which the maximum concentration of the zwitterion exists for an amino acid is referred to as the _____ .

A) isoelectric point
B) zwitterion ion point
C) neutral point
D) principal point
E) deprotonated point

Question 35

The ____ structure corresponds to the amino acid sequence in a molecule.

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

Question 36

The enzyme trypsin is used to break bonds in the following polypeptide. Gly-Lys-Met-Leu-Arg-Gly-Met-Arg-Lys
What fragments result?

A) Gly-Lys-Met;Leu-Arg-Met;Arg-Lys
B) Gly-Lys;Met-Leu-Arg;Gly-Met-Arg;Lys
C) Gly;Lys-Met-Leu-Arg-Gly;Met-Arg-Lys
D) Gly-Lys-Met-Leu-Arg;Gly-Met-Arg-Lys
E) Gly-Lys;Met-Leu;Arg-Gly;Met-Arg;Lys

Question 37

For valine (K_a1 = 5.2 × 10−³ and K_a2 = 1.9 × 10−¹⁰),what is the pH at the isoelectric point?

A) 2.28
B) 6.00
C) 7.00
D) 8.00
E) 9.72

Question 38

A certain polypeptide is shown by acid hydrolysis to contain only three amino acids: alanine (Ala),valine (Val),and serine (Ser)with mole fractions of , ,and ,respectively.Enzymatic hydrolysis yields the following fragments: Ala-Ser,Ala-Val,Val-Ala.What is the primary structure of the polypeptide?

A) Ala-Val-Ala-Ser
B) Ala-Ser-Ala-Val
C) Val-Ala-Ser-Ala
D) Ser-Ala-Ala-Val
E) Val-Ala-Ala-Ser

Question 39

How many tripeptides can be made from lysine,glycine,and valine,using any number of each amino acid?

A) 3
B) 4
C) 6
D) 9
E) 27

Question 40

How many tetrapeptides can be made from serine,alanine,glycine,and lysine,using each amino acid only once per tetrapeptide?

A) 4
B) 6
C) 12
D) 24
E) 36

Question 41

The three-dimensional conformation of a protein is called its

A) tertiary structure.
B) secondary structure.
C) conformational structure.
D) primary structure.
E) polymerized structure.

Question 42

Watson,Crick and Wilkins received the Nobel prize for

A) their work on DNA fingerprinting
B) determining the secondary structure of DNA
C) determining the identity of an unknown soldier
D) determining the primary structure of DNA
E) determining the tertiary structure of DNA

Question 43

Diols react with dioic acids to produce

A) polyamides and water
B) polyesters and water
C) condensation polymers and water
D) addition polymers
E) b and c