Deck 3: Biological Molecules

Question 1

An example of a structural polysaccharide is

A) maltose.
B) glycogen.
C) starch.
D) glucose.
E) cellulose.

Answer 1

E

Question 2

Prions are known to cause

A) mad cow disease.
B) herpes.
C) sickle cell anemia.
D) the common cold.

Answer 2

A

Question 3

You are telling your friend that organic molecules are all made up of carbon backbones with hydrogens. She doesnʹt understand how there can be so many different organic molecules if they all are made up of the same basic components. You explain that organic molecules

A) vary because they possess different functional groups.
B) are different because of the different types of hydrogen bonds that form.
C) vary because they possess different isotopes of carbon.
D) actually all have the same structure but differ in the number of electrons.

Answer 3

A

Question 4

Which of the following is NOT an organic molecule?

A) Lipid
B) Monosaccharide
C) Carbon monoxide
D) Protein
E) Nucleic acid

Question 5

Which of the following best explains the molecular complexity of living organisms?

A) Each organism has its own unique set of monomers for use in constructing polymers.
B) The large number of different monomers allows for the construction of many polymers.
C) Condensation reactions can create different polymers because they can combine virtually any molecules in the cell.
D) A small number of monomers can be assembled into large polymers with many different combinations/sequences.
E) Although there are not many biological molecules in cells, each one has many different functions.

Question 6

Hydrolysis may be correctly described as the

A) removal of water from a polymer.
B) breaking of a compound into its subunits by using water to break the bond between monomers.
C) heating of a compound in order to drive off its excess water and to concentrate its volume.
D) constant removal of hydrogen atoms from a carbohydrate.

Question 7

Keratin and silk are examples of_________ , whereas glucose and maltose are examples of _________.

A) carbohydrates; proteins
B) proteins; lipids
C) nucleic acids; lipids
D) proteins; carbohydrates

Question 8

Which of the following reactions is an example of dehydration synthesis?

A) Cellulose → glucose
B) Peptide → alanine + glycine
C) Fat → fatty acids + glycerol
D) Glucose + galactose → lactose
E) Glycogen → glucose subunits

Question 9

Which of the following best summarizes the relationship between dehydration reactions and hydrolysis?

A) Dehydration reactions occur only in animals, and hydrolysis reactions occur only in plants.
B) Dehydration reactions can occur only after hydrolysis.
C) Hydrolysis creates monomers, and dehydration reactions destroy them.
D) Dehydration reactions assemble polymers, and hydrolysis breaks them down.
E) Hydrolysis creates polysaccharides, and dehydration creates monosaccharides.

Question 10

Maltose is made from

A) two glucose molecules.
B) glucose and galactose.
C) two peptides.
D) glucose and fructose.

Question 11

If digestion_________ is , then synthesis is _________.

A) inorganic; organic
B) hydrolysis; dehydration synthesis
C) dehydration synthesis; hydrolysis
D) organic; inorganic

Question 12

Which molecule is a disaccharide?

A) Glucose
B) Lactose
C) Water
D) Fructose

Question 13

Chitin is an example of a

A) monomer.
B) triglyceride.
C) peptide.
D) polysaccharide.
E) nucleic acid.

Question 14

Large biological molecules are synthesized by removing

A) carbon.
B) water.
C) peptides.
D) covalent bonds.
E) oxygen.

Question 15

The carbohydrate in DNA is

A) ribose.
B) phosphate.
C) deoxyribose.
D) cellulose.
E) glucose.

Question 16

In dehydration synthesis, the atoms that make up a water molecule come from

A) carbohydrates.
B) oxygen.
C) both of the reactants.
D) enzymes.
E) only one of the reactants.

Question 17

What type of chemical reaction results in the breakdown of organic polymers into their respective subunits?

A) Condensation
B) Ionization
C) Oxidation
D) Hydrolysis

Question 18

Dehydration synthesis involves the removal of a hydrogen ion and a hydroxyl ion. What happens next?

A) A large polymer is split apart into small monomers.
B) A polysaccharide is released from a monosaccharide.
C) The hydrogen ion becomes an isotope.
D) The hydrogen and hydroxyl ions combine to form water.

Question 19

Where is glycogen stored in vertebrate animals?

A) Fat cells
B) Brain and kidneys
C) Teeth and bones
D) Pancreas and blood
E) Liver and muscles

Question 20

The fiber in your diet is actually

A) starch.
B) protein.
C) ATP.
D) cellulose.
E) glycogen.

Question 21

What property of phospholipids makes them important in cell membranes?

A) They have a polar end and a nonpolar end.
B) They contain nucleic acids.
C) They are found only in animals.
D) They are an important energy carrier molecule.
E) They are part of DNA.

Question 22

Which of the following categories includes monosaccharide monomers?

A) Carbohydrates
B) Lipids
C) Nucleic acids
D) Proteins

Question 23

Which of the following can serve as an energy source and as structural support in plant cells?

A) Carbohydrates
B) Lipids
C) Proteins
D) Nucleic acids

Question 24

Which type of lipid is most important in biological membranes?

A) Fat
B) Steroid
C) Oil
D) Phospholipid
E) Wax

Question 25

When 1 gram of each of these food sources is consumed, which yields the greatest amount of energy in calories?

A) Phenylalanine
B) Polypeptide
C) Fat
D) Sucrose
E) Glucose

Question 26

Triglycerides are

A) always composed of carbon rings.
B) polymers of amino acids.
C) hydrophilic.
D) a main component of cellular membranes.
E) made from glycerol and fatty acids.

Question 27

Two categories of organic compounds typically provide energy for living systems. Representatives of these two classes are

A) carbohydrates and proteins.
B) proteins and nucleic acids.
C) carbohydrates and nucleic acids.
D) lipids and proteins.
E) carbohydrates and lipids.

Question 28

All of the following lipids or lipid components are hydrophobic EXCEPT

A) saturated fats.
B) waxes.
C) fatty acid tails.
D) unsaturated fats.
E) fatty acid heads.

Question 29

Fats and oils are made of

A) three amino acids and one glycerol.
B) three glycerols and three fatty acids.
C) two fatty acids and one carboxyl acid.
D) three fatty acids and one glycerol.
E) one glycogen and two phospholipids.

Question 30

Which of the following is insoluble in water?

A) DNA
B) Salt
C) Amino acids
D) Olive oil
E) Sucrose

Question 31

Lactose is a disaccharide of glucose and galactose, and its digestion requires the actions of the enzyme lactase. If lactose is eaten as part of the diet but is not digested by lactase, this sugar is then metabolized by bacteria in the intestine, leading to the symptoms of lactose intolerance. Lactose intolerance, therefore, results from a(n)

A) lack of hydrolysis of lactose.
B) low blood lactose level.
C) lack of dehydration synthesis of lactose.
D) inability of the body to produce lactose.

Question 32

In humans, dental cavities form when Streptococcus mutans bacteria in the mouth hydrolyze sucrose. Which of the following is (are) the products of this reaction?

A) Glucose and fructose
B) Glucose and galactose
C) Glycogen
D) Starch

Question 33

The fat substitute Olestra contains a sucrose backbone with six to eight fatty acids attached. How is this different from a naturally occurring fat?

A) Naturally occurring fats contain a glycerol and three fatty acids.
B) Naturally occurring fats contain a sucrose backbone and three fatty acid chains.
C) It isnʹt; Olestra and natural fats have the same structure, just different tastes.
D) Naturally occurring fats contain a glycerol, two fatty acids, and a phosphate group.

Question 34

Lard is a solid fat at room temperature. What does this tell you about the triglycerides in lard?

A) Lard is composed of unsaturated fats.
B) Lard is composed of saturated fats.
C) The fats in lard are mostly phospholipids.
D) The fats in lard are not organic molecules.

Question 35

Imagine that you have isolated a mysterious liquid from a sample of food. You add the liquid to a beaker of water and shake vigorously. After a few minutes, the water and the other liquid separate into two layers. To which class of biological molecules does the unknown liquid most likely belong?

A) Carbohydrates
B) Lipids
C) Nucleic acids
D) Enzymes
E) Proteins

Question 36

Cholesterol, testosterone, and estrogen are examples of

A) proteins.
B) nucleic acids.
C) waxes.
D) fatty acids.
E) steroids.

Question 37

Cell membranes are an example of a lipid bilayer. In this lipid bilayer, both the outside of the cell and the inside of the cell are in nature.

A) charged
B) hydrophobic
C) polar
D) hydrophilic
E) watery

Question 38

New government regulations require that foods containing trans fats be labeled appropriately. A trans fat is formed when food manufacturers turn liquid oils into solid fats by adding hydrogen to vegetable oils. This hydrogenation process produces a solid fat because adding the hydrogen

A) forms a wax molecule.
B) allows fats to form tertiary and quaternary structures.
C) allows the fatty acid chains to pack together more tightly.
D) causes a phospholipid to form.

Question 39

Which of the following provides long-term energy storage for plants?

A) Glucose
B) Cellulose
C) Glycogen
D) Starch
E) ATP

Question 40

When the level of glucose in your blood is high, your body is able to store excess glucose in the liver by forming glycogen. When blood glucose levels fall, this stored glucose can be released. Based on this information, which of the following is TRUE?

A) Glycogen is a highly branched functional group that forms a larger glucose polymer.
B) Glycogen is a polysaccharide formed by joining excess monosaccharides of glucose.
C) Glucose is a polysaccharide that can join to form the monosaccharide glycogen.
D) Glucose is not an organic molecule, but glycogen is an organic molecule.

Question 41

Complex, three-dimensional, tertiary structures of proteins result from

A) ionic bonds.
B) ionic and hydrogen bonds
C) disulfide bonds.
D) hydrogen bonds.
E) hydrogen and disulfide bonds.

Question 42

Which type of molecule is most abundant in a typical cell?

A) Water
B) Carbohydrate
C) Lipid
D) Protein
E) Nucleic acids

Question 43

Proteins are constructed using how many different amino acids?
A) 1,000

A) 4
B) 20
D) 100
E) More than 5,000

Question 44

Which of the following statements about lipids is incorrect?

A) They are short chains of polar hydrocarbons.
B) They are used for energy storage.
C) They are hydrophobic and water insoluble.
D) They are large chains of nonpolar hydrocarbons.
E) They are primary component of cell membranes.

Question 45

Which of the following biological molecules possess large nonpolar regions, making them insoluble in water?

A) Carbohydrates
B) Lipids
C) Proteins
D) Nucleic acids

Question 46

A denatured protein differs from a normal protein because it

A) is composed of nucleotides.
B) does not contain amino acids.
C) contains many disulfide bonds.
D) has lost its usual secondary and tertiary structures.

Question 47

The bonding of two amino acid molecules to form a larger molecule requires which of the following?

A) Formation of a glycosidic bond
B) Removal of a water molecule
C) Addition of a water molecule
D) Both removal of a water molecule and formation of a hydrogen bond
E) Formation of a hydrogen bond

Question 48

Which of the following is TRUE about waxes?

A) They are a type of complex carbohydrate.
B) They are saturated fats and are solid at normal outdoor temperatures.
C) They are unsaturated and most similar to proteins.
D) They are an important food source, and most animals have enzymes for breaking them down.

Question 49

All of the following are polysaccharides EXCEPT

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

Question 50

The group of biological molecules that are most diverse in function is

A) proteins.
B) lipids.
C) carbohydrates.
D) nucleic acids.

Question 51

Which of the following is an example of a protein?

A) Cellulose
B) Estrogen
C) Keratin
D) ATP

Question 52

A peptide bond forms between which of these groups?

A) Carboxyl and aldehyde
B) Hydroxyl and carboxyl
C) Phosphate and hydroxyl
D) Carboxyl and amino
E) Amino and aldehyde

Question 53

HDL and LDL are different types of cholesterol found in the blood. These compounds are

A) lipids.
B) carbohydrates.
C) nucleic acids.
D) proteins.

Question 54

Enzymes are specialized_________ that catalyze chemical reactions within the body.

A) lipids
B) proteins
C) carbohydrates
D) nucleic acids

Question 55

The specific function of a protein is determined by the

A) fatty acids that are joined together in the polypeptide.
B) number of peptide bonds it contains.
C) hydrophilic head attached to the hydrophobic tail.
D) number of disulfide bonds.
E) exact sequence of amino acids.

Question 56

Which of the following groups is crucial to the structure and function of the sex hormones estrogen and testosterone?

A) Lipids
B) Carbohydrates
C) Nucleic acids
D) Proteins

Question 57

What do carbohydrates, lipids, and proteins have in common?

A) All are inorganic molecules.
B) All are important enzymes that function within the cell.
C) Covalent bonding holds these molecules together.
D) Polymers of these organic molecules form monomers via dehydration synthesis reactions.

Question 58

The four polypeptides that are joined together to make functional hemoglobin represent which level of protein organization?

A) Quaternary structure
B) Secondary structure
C) Primary structure
D) Tertiary structure

Question 59

Which of the following refers to the amino acid sequence of proteins?

A) Primary
B) Secondary
C) Tertiary
D) Quaternary

Question 60

What maintains the secondary structure of a protein?

A) Hydrogen bonds
B) Peptide bonds
C) Disulfide bonds
D) Ionic bonds

Question 61

Which of the following biological molecules are composed of monomer units containing a sugar, a phosphate group, and a nitrogen-containing base?

A) Carbohydrates
B) Lipids
C) Proteins
D) Nucleic acids

Question 62

Functional groups determine the characteristics and chemical reactivity of organic molecules.

Question 63

Many biological molecules are formed by the joining of monomer units in a(n)_________reaction (removal of water); the reverse process is called_________ .

Question 64

Which of the following may possess primary, secondary, tertiary, and quaternary structures?

A) Lipids
B) Nucleic acids
C) Carbohydrates
D) Proteins

Question 65

The ʺbackboneʺ of a nucleic acid molecule is made of

A) NAD+ and FAD.
B) amino acids.
C) sugar and phosphate groups.
D) lipids.
E) ATP molecules.

Question 66

Adenosine triphosphate (ATP) is an example of a(n)

A) inorganic molecule.
B) carbohydrate.
C) protein.
D) lipid.
E) nucleotide.

Question 67

DNA carries genetic information in its

A) sugar groups.
B) sequence of bases.
C) helical form.
D) phosphate groups.
E) tertiary structure.

Question 68

Scientists consider prions to be ʺpuzzlingʺ proteins. Which of the following is TRUE about prions?

A) Prions are proteins that are denatured more easily than most proteins.
B) Prions are proteins that cause nearby proteins to change shape and become infectious.
C) Prions are noninfectious proteins.
D) Prions are infectious proteins that cannot be denatured by any amount of heat.

Question 69

Your friend is trying to learn about how to kill bacteria. She reads that preservatives such as citric acid are added to foods because the acidic environment kills bacteria by denaturing their proteins. She thinks this sounds like a lot of scientific jargon and asks you what it means. How can you explain it in simpler terms?

A) The acid causes the cells to swell and burst open, also known as denaturation.
B) Denaturing their proteins means that the proteins in bacteria are converted into carbohydrates.
C) Denaturing refers to the fact that the bacterial cells divide too quickly and die.
D) Denaturing means that the proteins of the bacteria lose their structure and canʹt function, so the bacteria die.

Question 70

Phospholipids have hydrophilic tail regions and hydrophobic head regions.

Question 71

Carbon provides a backbone for a variety of biological molecules. Carbon can typically form _________covalent bonds.

Question 72

Your classmate is trying to keep all the facts about biological molecules straight. He asks you to explain how amino acids and proteins are related. What do you tell him?

A) Proteins are a portion of an amino acid.
B) Proteins are chains of carbohydrates, and amino acids are a type of lipid.
C) Proteins are made up of chains of amino acids.
D) Amino acids are formed by joining together many proteins.

Question 73

Which of these biological molecules contain genetic information?

A) Lipids
B) Carbohydrates
C) Proteins
D) Nucleic acids

Question 74

Suppose you have discovered a new virus and have isolated its nucleic acids. What feature could you look for to determine whether the nucleic acids of this virus are RNA or DNA?

A) If it is DNA, the virus will not contain proteins.
B) If it is RNA, there will be no adenine.
C) If is RNA, it will contain deoxyribose.
D) If it is RNA, it will contain ribose.

Question 75

Which of the following biological molecules are composed of amino acid subunits?

A) Proteins
B) Nucleic acids
C) Lipids
D) Carbohydrates

Question 76

How many hydrogen bonds exist between a G-C base pair?

A) 1
B) 2
C) 3
D) 4

Question 77

Which of the following correctly matches an organic polymer with its monomers, respectively?

A) Lipid; steroids
B) DNA; ATP
C) Carbohydrate; polysaccharides
D) Protein; amino acids
E) Hydrocarbon; monosaccharides

Question 78

Which of these is NOT a nucleic acid or nucleotide?

A) ATP
B) DNA
C) LDL
D) RNA

Question 79

A nucleotide is made of a

A) phosphate, protein, and nitrogenous base.
B) phospholipid, sugar, and protein.
C) phosphate, sugar, and nitrogenous base.
D) phospholipid, sugar, and nitrogenous base.

Question 80

Important biological molecules that have a carbon backbone bonded to hydrogen atoms are considered to be_________ .