Deck 5: Biological Macromolecules and Lipids

Question 1

Which of the following is a biological advantage of storing glucose molecules in branched polymers?

A) They can be stacked together to save space.
B) They are insoluble and so provide strength to the molecule.
C) They have more sites for enzymatic attack than do unbranched polymers.
D) They are resistant to enzymes.

Answer 1

C

Question 2

People who are lactose intolerant cannot extract energy from milk because ________.

A) an enzyme is not functioning correctly
B) lactose is too big to be digested by the enzymes
C) milk is fermented to a by-product, which cannot be digested
D) they are missing the bacteria that can digest lactose

Answer 2

A

Question 3

Which of the following statements is correct regarding starch and cellulose?

A) They are polymers of glucose.
B) They are cis and trans isomers of each other.
C) They are used for energy storage in plants and animals.
D) They are structural components of the plant cell wall.

Answer 3

A

Question 4

An amino acid is to a protein as a glucose molecule is to ________.

A) glycogen
B) a lipid
C) nucleic acid
D) a tripeptide

Question 5

Chitin is composed of glucose and ________.

A) fructose
B) lactose
C) amino acid
D) N-acetyl glucosamine

Question 6

During a 12-hour fast in a human, the first macromolecule to get depleted is typically ________.

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

Question 7

Which of the following terms does not describe a molecule of glucose?

A) an isomer of fructose
B) an aldose
C) a hexose
D) a disaccharide

Question 8

Which of the following best compares dehydration reactions and hydrolysis?

A) Dehydration reactions assemble polymers; hydrolysis reactions break polymers apart.
B) Dehydration reactions eliminate water from membranes; hydrolysis reactions add water to membranes.
C) Dehydration reactions and hydrolysis reactions assemble polymers from monomers.
D) Hydrolysis reactions assemble polymers; dehydration reactions break polymers apart.

Question 9

Why can humans digest starch but not cellulose?

A) Humans have enzymes that can hydrolyze the α-glycosidic linkages of starch but not the β-glycosidic linkages of cellulose.
B) Starch monomers are joined by covalent bonds, and cellulose monomers are joined by ionic bonds.
C) The monomer of starch is glucose, while the monomer of cellulose is galactose.
D) Starch is softer than cellulose.

Question 10

The molecular formula of a carbohydrate molecule is C24H42O₂1. The maximum number of glucose and water molecules that will be consumed by complete hydrolysis of the carbohydrate is ________.

A) 6 molecules of glucose and 3 molecules of water
B) 4 molecules of glucose and 4 molecules of water
C) 4 molecules of glucose and 3 molecules of water
D) 6 molecules of glucose and 5 molecules of water

Question 11

An individual experiences abdominal discomfort after consuming a drink containing milk. A loss of function of which enzyme is most likely responsible for the symptoms?

A) lactase that breaks down the bond between galactose and glucose
B) lactose that breaks down the bond between two glucose molecules
C) maltase that breaks down the bond between galactose and glucose
D) maltose that breaks down the bond between two glucose molecules

Question 12

Use the following figure to answer the question. What is the molecule represented by the figure above?

A) a hexose
B) a pentose
C) fructose
D) maltose

Question 13

The difference between an aldose sugar and a ketose sugar is ________.

A) the number of carbon atoms
B) the position of the hydroxyl groups
C) the position of the carbonyl group
D) the ring form and the linear chain

Question 14

The term insoluble fiber on food packages refers to which of the following molecules?

A) cellulose
B) polypeptides
C) starch
D) amylopectin

Question 15

Which of the following best describes glycogen?

A) a fibrous protein that helps in maintaining cellular structure
B) a storage polysaccharide found in plants
C) has alpha 1-6 glyosidic bonds.
D) is formed by the hydrolysis of glucose molecules.

Question 16

Maltose is a disaccharide that can easily be digested into glucose molecules. Which type of glycosidic linkage connects glucose molecules in maltose?

A) β 1-4
B) α 1-2
C) α 1-4
D) β 1-2

Question 17

Starch is composed of which of the following?

A) branched amylopectin and branched amylose
B) unbranched amylopectin and unbranched amylose
C) branched amylopectin and unbranched amylose
D) unbranched amylopectin and branched amylose

Question 18

How many molecules of water are required for the polymerization of a 22 monomer-long cellulose molecule?

A) 11
B) 21
C) 22
D) 44

Question 19

Which polysaccharide is an important component in the structure of many animal and fungal cells?

A) chitin
B) cellulose
C) amylopectin
D) amylose

Question 20

Which of the following is not analogous to a biological polymer?

A) a train
B) a pearl strand necklace
C) an iron chain
D) a truck

Question 21

Which part of an amino acid gives it its unique identity?

A) the long carbon-hydrogen tails of the molecule
B) the carboxyl and amino groups
C) the components of its side chain
D) the glycerol molecule that forms the backbone of the amino acid

Question 22

The following question is based on the 15 molecules illustrated in the figures.













Which molecule has both hydrophilic and hydrophobic properties and is found in plasma membranes?

A) 1
B) 5
C) 12
D) 14

Question 23

Which of the following statements about lipids is true?

A) Lipids are not organic in nature.
B) Lipids don't constitute of waxes and pigments.
C) Lipids mix poorly with water.
D) Lipids are true polymers.

Question 24

The label on a container of margarine lists "hydrogenated vegetable oil" as the major ingredient. Which of the following options describes the property of hydrogenated vegetable oil?

A) It is solid at room temperature.
B) It has more double bonds in the fatty acid chains.
C) It has fewer trans fatty acids.
D) It is less likely to block arteries.

Question 25

You have just sequenced a new protein isolated from mice and observe that sulfur-containing cysteine residues occur at regular intervals. "This finding is most consistent with which of the following claims about the protein?

A) Cysteine residues are required for the formation of α helices and β pleated sheets.
B) It will be important to include cysteine in the diet of the mice.
C) Cysteine residues are involved in disulfide bridges that help form tertiary structure.
D) Cysteine causes bends, or angles, to occur in the tertiary structure of proteins.

Question 26

Ovalbumin, the egg white protein is denatured in scrambled egg. Which of the following is not affected?

A) primary structure of ovalbumin
B) secondary structure of ovalbumin
C) tertiary structure of ovalbumin
D) quaternary structure of ovalbumin

Question 27

Which parts of the amino acids AA1 and AA2 are involved in the formation of a peptide bond?
AA1-AA2

A) amino group of AA1 and carboxyl group of AA2
B) carboxyl group of AA1 and amino group of AA2
C) carboxyl group of AA1 and side chain of AA2
D) side chains of both AA1 and AA2

Question 28

Which of the following statements about proteins is true?

A) Denaturation leads to bond disruption, and the molecule turns into liquid.
B) Denaturation is always irreversible.
C) Final folded structure can reveal the steps of protein folding.
D) Some proteins form a complete 3-D structure only when they interact with their targets.

Question 29

The following question is based on the 15 molecules illustrated in the figures.













Which molecule is a saturated fatty acid?

A) 1
B) 5
C) 8
D) 9

Question 30

The following question is based on the 15 molecules illustrated in the figures.













A fat (or triacylglycerol) would be formed as a result of a dehydration reaction between ________.

A) one molecule of 9 and three molecules of 10
B) three molecules of 9 and one molecule of 10
C) one molecule of 5 and three molecules of 9
D) one molecule of 5 and three molecules of 10

Question 31

Which of the following has been associated with atherosclerosis and should be eliminated from one's diet for health reasons?

A) butter
B) olive oil
C) liver and kidney organ meat
D) butter, liver, and kidney organ meat

Question 32

What is the role of hydrogen in the synthesis of "hardened fats" from vegetable oil?

A) Hydrogen reduces the number of carbon-carbon double bond.
B) Hydrogen causes hydrolysis to occur.
C) Hydrogen causes cross-linking between chains.
D) Hydrogen increases the carbon chain length.

Question 33

Which of the following statements correctly describes "saturated fats"?

A) They are more common in plants than in animals.
B) They have multiple double bonds in the carbon chains of their fatty acids.
C) They are generally liquid at room temperature.
D) They contain more hydrogen than unsaturated fats that consist of the same number of carbon atoms.

Question 34

Olestra is a calorie-free fat that is synthesized by reacting sucrose with fatty acids. What is the maximum number of fatty acid molecules that can crosslink with the sucrose molecule?

A) 3
B) 6
C) 8
D) 10

Question 35

In a bottle of salad dressing, the vinegar separates from the oil because ________.

A) water molecules form H-bonds with each other and exclude fat
B) vinegar and oil are lighter than water
C) water is lighter than vinegar and oil
D) oil is colorless, but vinegar is not

Question 36

Which of the following statements about hemoglobin is most consistent with the information in the passage?

A) a tertiary protein with two polypeptides
B) a quaternary protein with two polypeptides
C) a tertiary protein with four polypeptides
D) a quaternary protein with four polypeptides

Question 37

Which of the following features of cooking oil and gasoline (hydrocarbons) identifies why the molecules are NOT amphipathic?

A) They do not have a polar or charged region.
B) They do not have a nonpolar region.
C) They have hydrophobic and hydrophilic regions.
D) They are highly reduced molecules.

Question 38

Extraction of lipids from a tissue sample requires organic solvent because ________.

A) organic solvents are easily accessible
B) lipids are hydrophobic, and they can only be solubilized in organic solvent
C) organic solvents keep the temperature low and manageable
D) organic solvents are cheaper

Question 39

How many amino acids and peptide bonds does a tetrapeptide have?

A) four amino acids and three peptide bonds
B) four amino acids and four peptide bonds
C) three amino acids and four peptide bonds
D) four amino acids and two peptide bonds

Question 40

Which of the following statements describes the interaction of water molecules with phospholipids?

A) The polar heads avoid water; the nonpolar tails attract water (because water is polar and opposites attract).
B) Phospholipids do not interact with water because water is polar and lipids are nonpolar.
C) The polar heads interact with water; the nonpolar tails do not.
D) Phospholipids dissolve in water.

Question 41

When nucleotides polymerize to form a nucleic acid, ________.

A) a covalent bond forms between the sugar of one nucleotide and the phosphate of a second
B) a hydrogen bond forms between the sugar of one nucleotide and the phosphate of a second
C) covalent bonds form between the bases of two nucleotides
D) hydrogen bonds form between the bases of two nucleotides

Question 42

The following question is based on the 15 molecules illustrated in the figures.













Which of the following pairs of molecules could be joined together by a peptide bond in a dehydration reaction?

A) 2 and 3
B) 7 and 8
C) 8 and 9
D) 12 and 13

Question 43

Which of the following is the primary function of RNA molecule?

A) transmit genetic information to offspring
B) function in the synthesis of proteins
C) make a copy of itself, thus ensuring genetic continuity
D) act as a pattern or blueprint to form DNA

Question 44

Which of the following is similar between RNA and DNA?

A) type of sugar
B) type of pyrimidine base
C) type of purine base
D) number of strands

Question 45

Which of the following statements about the 5′ end of a polynucleotide strand of RNA is correct?

A) It has a hydroxyl group attached to the number 5 carbon of ribose.
B) It has a phosphate group attached to the number 5 carbon of ribose.
C) It has phosphate attached to the number 5 carbon of the nitrogenous base.
D) It has a carboxyl group attached to the number 5 carbon of ribose.

Question 46

The following question is based on the 15 molecules illustrated in the figures.













Which of the following molecule when added to nucleoside turns it into a nucleotide?

A) 2
B) 6
C) 11
D) 11 and 13

Question 47

Use the following table to answer the question.
Absorbance at Various pH Levels

The table represents the results of an experiment where the effects of pH buffers on an enzyme found in saliva (amylase) were studied. A spectrophotometer set at 500 nm was used to measure absorbance at the various pH levels every 20 seconds for 2 minutes. The higher absorbance values would indicate greater enzyme activity. All experiments were conducted at the same temperature.
Which statement correctly identifies the result that the optimum pH for amylase function is 7?

A) The pH with the lowest absorbance values would indicate the optimum pH for amylase since this pH does not affect the structure or function of the protein.
B) The pH with the highest absorbance values would indicate the optimum pH for amylase since this pH does not affect the structure or function of the protein.
C) At pH 9, the enzyme is denatured and will lose its function, but not its structure.
D) At pH 4, the structure of the enzyme will be altered, and the enzyme would not be able to catalyze the reaction.

Question 48

Which of the following is a palindromic sequence?

A) 5′-AGGTCC-3′ 3′-TCCAGG-5′
B) 5′-CCTTCC-3′ 3′-GCAAGG-5′
C) 5′-GAATCC-3′ 3′-CTTAGG-5′
D) 5′-GGATCC-3′ 3′-CCTAGG-5′

Question 49

If one strand of a DNA molecule has the sequence of bases 5′-ATTGCA-3′, the mRNA synthesized following the template will be ________.

A) 5′-TAACGT-3′
B) 5′-TGCAAT-3′
C) 3′-UAACGU-5′
D) 5′-UGCAAU-3′

Question 50

Which of the following can be used to predict the 3-D structure of the protein?

A) peptide bonds between different amino acids
B) sequence of amino acids in the polypeptide chain
C) side chains of various amino acids
D) number of water molecules in the vicinity

Question 51

Use the following figure to answer the question. Which of the following chemical reactions is represented in the figure?

A) is a hydrolysis reaction
B) results in a peptide bond
C) joins two fatty acids together
D) links two polymers to form a monomer

Question 52

Hemoglobin, when subjected to 40% acetonitrile at pH 10.0, loses its quaternary structure, which means the ________.

A) four α and β polypeptides dissociate
B) peptide bonds between amino acids break
C) α and β polypeptides lose their 3-D structure
D) four α and β polypeptides dissociate, peptide bonds between amino acids, and α and β polypeptides lose their 3-D structure

Question 53

Which of the following are possible base compositions for double-stranded DNA?
%A %G %C %T %U

A) 5 45 45 5 0
B) 20 20 20 20 20
C) 35 15 35 15 0
D) All of the above

Question 54

The following question is based on the 15 molecules illustrated in the figures.













Which of the following molecules is a disaccharide?

A) 1 and 4
B) 3
C) 6
D) 15

Question 55

In sickle-cell disease, as a result of a single amino acid change, the mutant hemoglobin tetramers associate with each other and assemble into large fibers. Based on this information alone, what does the sickle-cell hemoglobin exhibit?

A) only altered primary structure
B) only altered tertiary structure
C) only altered quaternary structure
D) altered primary structure and altered quaternary structure; the secondary and tertiary structures may or may not be altered

Question 56

If 14C-labeled uracil is added to the growth medium of cells, what macromolecules will be labeled?

A) DNA
B) RNA
C) both DNA and RNA
D) polypeptides

Question 57

The "flow of genetic information" in molecular biology follows the following path, ________.

A) DNA is transcribed into RNA, which is translated into protein
B) DNA is translated into protein
C) DNA is translated into RNA, which is transcribed into protein
D) RNA is transcribed into protein

Question 58

Based on the information in the passage, the total number of heme groups present in four hemoglobin protein molecules is ________.

A) 4
B) 8
C) 12
D) 16

Question 59

Misfolding of polypeptides is a serious problem in cells. Which of the following diseases are associated with an accumulation of misfolded polypeptides?

A) Alzheimer's only
B) Parkinson's only
C) Diabetes mellitus
D) Alzheimer's and Parkinson's

Question 60

Which of the following ratios of nucleotides is constant for DNA?

A) A + G = T + C
B) A + T = G + C
C) A + C = U + G
D) A + U = G + C

Question 61

Which of the following pairs of base sequences could form a short stretch of a normal double helix of DNA?

A) 5′-AGCT-3′ with 5′-TCGA-3′
B) 5′-GCGC-3′ with 5′-TATA-3′
C) 5′-ATGC-3′ with 5′-GCAT-3′
D) All of these pairs are correct.

Question 62

The following question is based on the 15 molecules illustrated in the figures.













Which of the following molecules is a purine nitrogenous base?

A) 2
B) 5
C) 12
D) 13

Question 63

The enzyme amylase can break glycosidic linkages between glucose monomers only if the monomers are in the α form. Which of the following could amylase break down?

A) glycogen, starch, and amylopectin
B) glycogen and cellulose
C) cellulose and chitin
D) starch, chitin, and cellulose

Question 64

Homo sapiens have 23 pairs of chromosomes. What does the number '23' represent here?

A) 46 double-stranded DNA molecules in each somatic cell
B) 23 single-stranded DNA molecules in each somatic cell
C) 23 double-stranded DNA molecules in each somatic cell
D) several hundreds of genes on DNA but not on the chromosomes

Question 65

The following question is based on the 15 molecules illustrated in the figures.













Which of the following molecules is the pentose sugar found in RNA?

A) 1
B) 6
C) 12
D) 13

Question 66

A new organism is discovered in the forests of Costa Rica. Scientists there determine that the polypeptide sequence of hemoglobin from the new organism has 72 amino acid differences from humans, 65 differences from a gibbon, 49 differences from a rat, and 5 differences from a frog. These data suggest that the new organism is more closely related to ________.

A) humans than to frogs
B) frogs than to humans
C) rats than to frogs
D) gibbons than to rats

Question 67

The structural level of a protein least affected by a disruption in hydrogen bonding is the ________.

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

Question 68

Enzymes that break down DNA catalyze the hydrolysis of the covalent bonds that join nucleotides together. What would happen to DNA molecules treated with these enzymes?

A) The two strands of the double helix would separate.
B) The phosphodiester linkages of the polynucleotide backbone would be broken.
C) The pyrimidines would be separated from the deoxyribose sugars.
D) All bases would be separated from the deoxyribose sugars.

Question 69

The molecular formula for glucose is C6H12O₆. What would be the molecular formula for a polymer made by linking ten glucose molecules together by dehydration reactions?

A) C60H120O₆0
B) C60H102O51
C) C60H100O50
D) C60H111O51

Question 70

Which of the following categories includes all others in the list?

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

Question 71

Which statement about unsaturated fats is true?

A) They are more common in animals than in plants.
B) They have double bonds in their fatty acid chains.
C) They generally solidify at room temperature.
D) They contain more hydrogen than do saturated fats having the same number of carbon atoms.