Deck 3: The Chemistry of Life: Organic Compounds

Question 1

Glucose dissolves in water because:

A) it ionizes.
B) it is a polysaccharide.
C) it has polar hydroxyl groups that interact with polar water molecules.
D) it has a very reactive primary structure.
E) it is hydrophobic.

Answer 1

C

Question 2

The highly polarized nature of compounds containing carboxyl groups can be attributed to the presence of two:

A) highly electronegative carbon atoms.
B) highly electropositive carbon atoms.
C) highly electronegative oxygen atoms.
D) highly electropositive oxygen atoms.
E) highly electropositive nitrogen atoms.

Answer 2

C

Question 3

Figure 3-1
Use the figure below to answer the corresponding question(s).
The products of the process in Figure 3-1 are:

A) amino acids.
B) molecules of glycerol.
C) representative of a glycoside linkage.
D) enzymes.
E) monosaccharides.

Answer 3

E

Question 4

Which of the following is not a property of carbon?

A) Carbon-to-carbon bonds are limited to single bonds.
B) Carbon has four valence electrons.
C) Carbon can form bonds to various other atoms.
D) Two carbon atoms can share three electron pairs with each other.
E) Carbon-to-carbon bonds are strong.

Question 5

Which pair is mismatched?

A) monsaccharide-maltose
B) disaccharide-sucrose
C) polysaccharide-cellulose
D) hexose-glucose
E) pentose-ribose

Question 6

Hydrocarbons are hydrophobic because:

A) the covalent bonds between hydrogen and carbon are nonpolar.
B) they contain oxygen atoms.
C) they exist as isomers.
D) the covalent bonds between carbon atoms are polar.
E) the hydrogen bonds between hydrogen and carbon are nonpolar.

Question 7

The two molecules in the following figure represent:

A) ionized structures.
B) enantiomers.
C) secondary structures.
D) geometric isomers.
E) polymers.

Question 8

Carbohydrate molecules:

A) serve as structural components of human cell walls.
B) form the regulatory compounds known as enzymes.
C) are a source of energy.
D) help protect vital organs from damage.
E) contain the genetic information of a cell.

Question 9

The difference between a hexose and a pentose is that:

A) a hexose is saturated, and a pentose is undersaturated.
B) a hexose is hydrophilic, and a pentose is hydrophobic.
C) a hexose always has six hydroxyl groups, and a pentose always has five.
D) a hexose always has six carbons, but a pentose always has five carbons.
E) a hexose can be polymerized, but a pentose cannot.

Question 10

A chemical reaction in which polymers are synthesized from their building blocks is called:

A) hydrolysis.
B) condensation.
C) oxidation.
D) reduction.
E) dissociation.

Question 11

The chemical interactions of large organic molecules are largely determined by:

A) their solubility in water.
B) their functional groups.
C) their polar nature.
D) isomerization of these hydrocarbons into other forms.
E) the hydrogens bonded to the carbon atoms.

Question 12

Amyloplasts are organelles that store:

A) fat.
B) starch.
C) protein.
D) lipids.
E) DNA.

Question 13

Monosaccharides are water soluble because:

A) they contain a large number of methyl groups.
B) they have a large number of polar hydroxyl groups.
C) they have at least one double bond between adjacent carbons.
D) they have large numbers of nonpolar carbons in their backbones.
E) they can form ring structures.

Question 14

Figure 3-1
Use the figure below to answer the corresponding question(s).
The process illustrated in Figure 3-1 is called:

A) condensation.
B) protein synthesis.
C) hydrolysis.
D) dehydration synthesis.
E) denaturation.

Question 15

Which of the following illustrates hydrolysis?

A) the reaction of two monosaccharides to form a disaccharide
B) the reaction of two amino acids to form a dipeptide
C) the reaction of a hydrogen atom and a hydroxide ion to form water
D) the reaction of a fat to form glycerol and fatty acids
E) the formation of ATP from ADP and inorganic phosphate

Question 16

Which one of the following carbohydrates is the most structurally complex?

A) sucrose
B) fructose
C) cellulose
D) glucose
E) a disaccharide

Question 17

The number of electron pairs shared between carbon 2 and 3 in the accompanying figure is:

A) one.
B) one and a half.
C) two.
D) three.
E) four

Question 18

This functional group is weakly basic because it can accept an H⁺ ion:

A) hydroxyl
B) carbonyl
C) amino
D) phosphate
E) sulfhydryl

Question 19

Which of these terms is most inclusive?

A) monosaccharide
B) starch
C) polysaccharide
D) disaccharide
E) carbohydrate

Question 20

Figure 3-1
Use the figure below to answer the corresponding question(s).

-In which of the following reactions must the equivalent of a water molecule be added in order to break a bond?

A) fatty acids + glycerol $\rightarrow$ fat
B) glucose + fructose $\rightarrow$ sucrose
C) glycogen $\rightarrow$ glucose
D) alanine + glycine $\rightarrow$ dipeptide
E) glucose $\rightarrow$ cellulose

Question 21

The primary difference between the amino acids commonly found in proteins is in their:

A) R or variable groups.
B) number of potassium groups.
C) number of phosphate groups.
D) number of carbonyl groups.
E) number of asymmetric carbons.

Question 22

If you partially hydrogenate oleic acid, the resulting molecule most likely would:

A) decrease the risk of cardiovascular disease.
B) contain more double bonds.
C) lose a carbon atom.
D) lose a carboxyl group.
E) have a double bond changed from cis to trans.

Question 23

Which of the following is responsible for the alpha-helical structure of proteins?

A) hydrophobic interactions
B) nonpolar covalent bonds
C) ionic interactions
D) hydrogen bonds
E) polar covalent bonds

Question 24

The hydrolysis of triacylglycerol will yield:

A) three fatty acids and one glycerol.
B) three glycerols and one fatty acid.
C) two fatty acids and three glycerols.
D) one fatty acid, one amino acid, and one glucose.
E) one fatty acid, one phosphate, and one glycerol.

Question 25

Proteins with alpha-helical forms exhibit this property:

A) strength.
B) elasticity.
C) heat stability.
D) rigidity.
E) hydrophobicity.

Question 26

A molecule of a saturated triacylglycerol contains:

A) the maximum number of double bonds between carbons in the fatty acid chains.
B) the maximum number of triple bonds between carbons in the fatty acid chains.
C) the maximum number of hydrogen atoms in the fatty acid chains.
D) fatty acid chains with both amino and carboxyl groups.
E) alternating single and double bonds between carbons in the fatty acid chains.

Question 27

What macromolecule is composed entirely of beta-glucose units?

A) starch
B) chitin
C) glycogen
D) cellulose
E) protein

Question 28

At which level of protein structure are peptide bonds most important?

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

Question 29

You isolate a compound that is insoluble in water, has alternating single and double bonds, and has a bright orange color.You correctly conclude that this compound is a:

A) protein.
B) nucleic acid.
C) polysaccharide.
D) steroid.
E) carotenoid.

Question 30

An amphipathic molecule has:

A) two polar ends.
B) two hydrophobic ends.
C) a hydrophobic and a hydrophilic portion.
D) only one hydrophobic end.
E) only one hydrophilic end.

Question 31

The most abundant molecules in this structure are:

A) structural proteins.
B) polysaccharides.
C) triacylglycerols.
D) phospholipids.
E) polypeptides.

Question 32

The following amino acid would be characterized as __________ based on the chemical properties of its side chain.

A) nonpolar
B) acidic
C) basic
D) hydrophilic
E) electrically charged

Question 33

The major difference between a structural lipid, such as those in cell membranes, and a storage fat is the fact that the structural lipid:

A) most commonly contains phosphate.
B) does not contain glycerol.
C) has four fatty acids attached to glucose.
D) is entirely hydrophobic.
E) is nonpolar.

Question 34

Regulatory proteins:

A) defend against foreign invaders.
B) store nutrients.
C) catalyze a specific chemical reaction.
D) control the expression of specific genes.
E) strengthen and protect cells and tissues.

Question 35

Some proteins are important biological buffers because:

A) they react with water to produce carbon dioxide, which neutralizes acids.
B) they contain acidic as well as basic groups.
C) they are able to absorb great amounts of carbon dioxide during condensation reactions.
D) they produce carbonic acid upon hydrolysis.
E) they contain nonpolar groups that exclude water molecules.

Question 36

Which of the following statements concerning unsaturated fats is correct?

A) They are more common in animals.
B) They have no double bonds in the carbon chains of their fatty acids.
C) They are generally liquid at room temperature.
D) They contain more hydrogen than do saturated fats having the same number of carbon atoms.
E) They have fewer fatty acids per fat molecule than do saturated fats.

Question 37

Which of the following is NOT true of lipids?

A) They store energy.
B) They function as structural components of cellular membranes.
C) They function as hormones.
D) They are nonpolar.
E) They have many oxygen-containing functional groups.

Question 38

Which of the following molecules is not grouped with the lipids?

A) prostaglandins.
B) steroids.
C) cholesterol.
D) carotenoids.
E) glycoproteins

Question 39

A carbohydrate energy storage molecule found in animal liver and muscle cells is:

A) starch.
B) glycogen.
C) cellulose.
D) a fatty acid.
E) cholesterol.

Question 40

Which of the following statements concerning steroids is FALSE?

A) They can function as hormones.
B) They are exemplified by cholesterol.
C) They consist of four attached carbon rings.
D) They are synthesized from isoprene units.
E) They contain phosphodiester linkages.

Question 41

Which of the following statements is false?

A) DNA is usually composed of two nucleotide strands.
B) DNA contains deoxyribose.
C) DNA does not normally contain uracil.
D) The nucleotides of DNA are linked by phosphodiester linkages.
E) DNA does not normally contain a phosphate group.

Question 42

DNA most directly determines which __________ are made by a cell.

A) polysaccharides
B) polypeptides
C) nucleotides
D) triglycerides
E) fatty acids

Question 43

Figure 3-2
Use the figure below to answer the corresponding question(s).
Hydrophobic interactions would occur between the R groups of which two amino acids in Figure 3-2?

A) 1 and 4
B) 2 and 5
C) 3 and 6
D) 2 and 4
E) 3 and 5

Question 44

ATP is important in living organisms because:

A) like all other nucleic acids, it stores hereditary information.
B) like RNA, it acts as a source code for the formation of proteins.
C) it can transfer some of its energy to other chemicals.
D) it is an important structural component of cell membranes.
E) it is easily converted to starch for long-term storage.

Question 45

This molecule transmits heredity information:

A) cholesterol.
B) adenosine triphosphate.
C) nucleic acid.
D) fatty acid.
E) polysaccharide.

Question 46

Which of the following statements is true of proteins?

A) Proteins lose some or all of their normal activity if their three-dimensional structure is disrupted.
B) Proteins are composed of ribose, phosphate, and a nitrogen-containing base.
C) The activity of proteins is independent of temperature and pH.
D) Denaturation is usually reversible.
E) All proteins are enzymes.

Question 47

This functional group forms bridges that help stabilize protein quaternary structure:

A) hydroxyl
B) carbonyl
C) amino
D) phosphate
E) sulfhydryl

Question 48

If tyrosine and isoleucine undergo condensation, the new bond that is formed is between the:

A) oxygen of the R group and the hydrogen of the amino group.
B) carbon of the R group and the nitrogen of the amino group.
C) carbon of the carboxyl group and the hydrogen of the R group.
D) carbon of the carboxyl group and the hydrogen of the amino group.
E) carbon of the carboxyl group and the nitrogen of the amino group.

Question 49

Figure 3-2
Use the figure below to answer the corresponding question(s).
In Figure 3-2, ionic bonds would form between the R groups of which amino acids?

A) 1 and 3
B) 2 and 4
C) 3 and 5
D) 4 and 6
E) 3 and 6

Question 50

Figure 3-3
Use the figure to answer the corresponding question(s).
Analysis of a certain polymer shows that it contains phosphate groups, ribose groups, and pyrimidines.Based on this information, which of the following is the best description of this compound?

A) It is most likely ribonucleic acid.
B) It is DNA.
C) It is an inorganic compound.
D) It contains thymine.
E) It is a polypeptide.

Question 51

Figure 3-3
Use the figure to answer the corresponding question(s).
The molecular fragment represented in Figure 3-3 is:

A) ATP.
B) RNA.
C) a protein.
D) a nucleotide.
E) a polysaccharide.

Question 52

When a nucleic acid undergoes hydrolysis, the resulting subunits are:

A) amino acids.
B) monosaccharides.
C) nucleotides.
D) fatty acids.
E) carotenoids.

Question 53

Figure 3-3
Use the figure to answer the corresponding question(s).
The type of connection between the atoms at the point labeled 1 in Figure 3-3 is:

A) a peptide bond.
B) a glycoside linkage.
C) a disulfide bond.
D) a phosphodiester linkage.
E) a hydrogen bond.

Question 54

If the differently shaded portions of this molecule represent different polypeptide chains, then this figure is representative of:

A) an amino acid.
B) the quaternary structure of a protein.
C) a steroid hormone.
D) cellulose.
E) a carotenoid.

Question 55

Which portion of the following molecule is most directly involved in transferring energy?

A) 1
B) 2
C) 3
D) 1 and 2
E) 2 and 3

Question 56

Which of the following statements best summarizes the differences between RNA and DNA?

A) RNA is a protein and DNA is a nucleic acid.
B) DNA is a polymer and RNA is a monomer.
C) DNA comprises the genes, while RNA is a direct participant in the process of protein synthesis.
D) RNA is a single-stranded form of DNA.
E) DNA is the primary energy currency of all cells.

Question 57

All of the following types of chemical bonds are responsible for maintaining the tertiary structure of this polypeptide except:

A) ionic bonds.
B) hydrogen bonds.
C) hydrophobic interactions.
D) disulfide bonds.
E) peptide bonds.

Question 58

Figure 3-2
Use the figure below to answer the corresponding question(s).
The tertiary structure of proteins is typified by the:

A) association of several polypeptide chains by weak bonds.
B) order in which amino acids are joined in a peptide chain.
C) bonding of two amino acids to form a dipeptide.
D) folding of a peptide chain to form an alpha helix.
E) three-dimensional shape of an individual polypeptide chain.

Question 59

Which pair matches the correct macromolecule with the bond that joins its subunits?

A) polysaccharide-peptide bond
B) triacylglycerol-glycosidic linkage
C) nucleic acid-phosphodiester linkage
D) protein-ester linkage
E) steroid-peptide bond

Question 60

Molecular chaperones are proteins that mediate the folding process of:

A) other proteins.
B) amino acids.
C) lipids.
D) DNA.
E) sugars.

Question 61

Identify the levels of organization for protein molecules, and list the type(s) of bond(s) involved in establishing each structural level.

Question 62

A beta-pleated sheet is an example of a protein's tertiary structure.
__________________

Question 63

Cyclic AMP is a type of nucleotide.
__________________

Question 64

Molecular chaperones mediate the folding of other protein molecules.
__________________

Question 65

A pyrimidine is double-ring molecule.
__________________

Question 66

A disaccharide is composed of two monosaccharides joined by a glycosidic linkage.
__________________

Question 67

The phosphate group is a nonpolar group.
__________________

Question 68

When glucose and fructose undergo condensation, maltose is produced as a product.
__________________

Question 69

Compare and contrast the structure, physical characteristics, and biological functions of two of the following: fats, steroids, and phospholipids.

Question 70

A single protein may have several domains.
__________________

Question 71

Water is always released as a product in hydrolysis reactions.
__________________

Question 72

Identify three functions of proteins other than enzymes and briefly discuss or describe each.

Question 73

Glycogen consists of beta-glucose monomers.
__________________

Question 74

What does the term "functional group" mean in reference to the structure of organic molecules? Identify two types of functional groups and describe their chemical properties.

Question 75

Fats high in unsaturated fatty acids tend to be solid at room temperature.
__________________

Question 76

By definition, geometric isomers are mirror images of each other.
__________________

Question 77

Chitin is a polymer composed of N-acetyl glucosamine monomers.
__________________

Question 78

Carotenoids are composed of isoprene subunits.
__________________

Question 79

The carboxyl group can exist in an ionized form and also in a nonionized form.
__________________

Question 80

An essential amino acid is one that the body cannot synthesize in sufficient amounts.
__________________