Deck 3: Molecules of Life

Question 1

A -CH₃ group is a(n) __________ group.

A)carboxyl
B)hydroxyl
C)amino
D)methyl
E)carbonyl

Answer 1

D

Question 2

A single atom of carbon may form up to __________ covalent bonds with other atoms.

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

Answer 2

C

Question 3

The breakdown of large molecules by the enzymatic addition of water is what kind of reaction?

A)oxidation
B)reduction
C)condensation
D)hydrolysis
E)decarboxylation

Answer 3

D

Question 4

The figure below illustrates a __________ reaction that produces a __________.

A)condensation; hydroxyls; polymer
B)condensation; water molecule
C)cleavage; water molecules; monomer
D)rearrangement; water molecules; polymer
E)rearrangement; hydrogen ions; polymer

Question 5

The backbone of organic molecules consists of covalently bonded __________ atoms.

A)oxygen
B)hydrogen
C)functional-group
D)carbon
E)all of these

Question 6

An -OH group is a(n) __________ group.

A)carboxyl
B)hydroxyl
C)amino
D)methyl
E)carbonyl

Question 7

Trans fats are found in

A)small amounts in red meats.
B)large amounts in partially hydrogenated oils.
C)dairy products.
D)alcoholic drinks.
E)A, B, and C are correct.

Question 8

A hydrolysis reaction results in

A)formation of a macromolecule.
B)bond breakage of a macromolecule.
C)lipid molecule creation.
D)nucleic acids being made.
E)most macromolecules.

Question 9

_______ are complex carbon ring structures that often have an iron atom at their center.

A)Hemes
B)Globins
C)Globulins
D)Sugars
E)Alkenes

Question 10

Which of the following is NOT one of the five categories of enzyme catalyzed reactions?

A)functional group transfer
B)electron transfer
C)condensation
D)cleavage
E)neutralization

Question 11

An -NH₂ group is a(n) __________ group.

A)carboxyl
B)hydroxyl
C)amine
D)methyl
E)carbonyl

Question 12

Hydrogenation is a chemical process that

A)turns liquid oil to solid fats.
B)turns amino acids into proteins.
C)turns DNA into lipids.
D)creates stable alternative energy sources.
E)does none of these.

Question 13

Hardening of the arteries is also known as

A)atherosclerosis.
B)apoptosis.
C)abuildosis.
D)keritosis.
E)all of these.

Question 14

Typical fat molecules have __________ tail(s).

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

Question 15

A -COOH group is a(n) _____ group.

A)carboxyl
B)hydroxyl
C)amino
D)methyl
E)carbonyl

Question 16

Although carbon dioxide contains carbon, it is not considered an "organic" compound because

A)it is not found in the earth's crust.
B)it is not present in living cells.
C)the carbon atom is not bonded to at least one hydrogen atom.
D)the carbons are not in chains or rings.
E)it is too small.

Question 17

The atom present in all organic compounds is

A)carbon.
B)oxygen.
C)nitrogen.
D)sulfur.
E)hydrogen.

Question 18

Fats are major constituents of

A)proteins.
B)genes.
C)photosynthesis.
D)cell membranes.
E)all of these.

Question 19

The three most common atoms in the human body are

A)hydrogen, oxygen, and carbon.
B)carbon, hydrogen, and nitrogen.
C)carbon, nitrogen, and oxygen.
D)nitrogen, hydrogen, and oxygen.
E)carbon, oxygen, and sulfur.

Question 20

What kind of reaction produces large molecules by linking small molecules?

A)oxidation
B)reduction
C)condensation
D)hydrolysis
E)decarboxylation

Question 21

Condensation and hydrolysis are accomplished in cells by

A)bonding attraction.
B)the action of enzymes.
C)spontaneous action.
D)functional group interactions.
E)all of these.

Question 22

Glucose and fructose

A)form rings with the same number of carbon atoms.
B)both have an oxygen atom as part of their ring structure.
C)are alike in that both have identical functional groups.
D)contain the same number of hydrogen atoms and hydroxyl groups.
E)are disaccharides.

Question 23

Which substances are the most plentiful biological molecules in the biosphere?

A)carbohydrates
B)salts and minerals
C)proteins
D)fats
E)nucleic acids

Question 24

Which reaction breaks down large molecules into smaller molecules?

A)synthesis
B)cleavage
C)condensation
D)polymerization
E)both cleavage and condensation

Question 25

Four of the five substances listed below are related by a common chemical similarity.Select the exception.

A)amylose
B)maltose
C)sucrose
D)lactose
E)all these are disaccharides

Question 26

Sucrose is composed of

A)two molecules of fructose.
B)two molecules of glucose.
C)a molecule of fructose and a molecule of glucose.
D)a molecule of fructose and a molecule of galactose.
E)a monosaccharide and a disaccharide.

Question 27

The final by-products of many condensation reactions are

A)carbon dioxide molecules.
B)hydrogen ions.
C)hydroxyl ions.
D)oxygen gas and hydrogen gas.
E)water molecules.

Question 28

Glucose and fructose are different

A)in the number of carbons they possess.
B)in their proportion in sucrose molecules.
C)in the way that their atoms are arranged.
D)in the number of double bonds they possess.
E)both in the way that their atoms are arranged and in the number of double bonds they possess.

Question 29

Plants store their excess carbohydrates in the form of

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

Question 30

Condensation reactions typically produce

A)monomers.
B)salts.
C)polymers.
D)simple sugars.
E)amino acids.

Question 31

Monosaccharides may be characterized by all EXCEPT which of the following?

A)a ketone group
B)carbon, hydrogen, and oxygen in a 1:2:1 ratio
C)a backbone of five to six carbon atoms
D)one aldehyde group
E)the presence of glycerol and fatty acids

Question 32

The combination of glucose and galactose forms

A)fructose.
B)maltose.
C)lactose.
D)sucrose.
E)a polysaccharide.

Question 33

The most plentiful sugar in nature is

A)glucose.
B)sucrose.
C)fructose.
D)maltose.
E)lactose.

Question 34

_____ refers to activities by which cells acquire and use energy.

A)Condensation
B)Hydrolysis
C)Synthesis
D)Metabolism
E)Dehydration

Question 35

Sugars are characterized by all EXCEPT which one of the following functional groups?

A)hydroxyl
B)carbonyl
C)ketone
D)aldehyde
E)methyl

Question 36

Which is a monomer?

A)chitin
B)cellulose
C)amylose
D)sucrose
E)glucose

Question 37

Glucose and sugars in DNA and RNA

A)have the same number of carbon atoms.
B)have the same structural formulas.
C)are the two components of sucrose.
D)are monosaccharides.
E)are both components of RNA.

Question 38

Which of the following is composed of a 1:2:1 ratio of carbon to hydrogen to oxygen?

A)carbohydrate
B)protein
C)lipid
D)nucleic acid
E)steroid

Question 39

Fructose and glucose are

A)able to combine to form sucrose.
B)structurally different.
C)monosaccharides.
D)simple sugars.
E)all of these.

Question 40

Fructose and glucose are

A)isotopes.
B)monosaccharides.
C)disaccharides.
D)six-carbon sugars.
E)both monosaccharides and six-carbon sugars.

Question 41

When glucose is in short supply, plants will quickly hydrolyze

A)glycogen.
B)starch.
C)cellulose.
D)sucrose.
E)fructose.

Question 42

Which of these components of a tossed salad will pass through the human digestive tract with the least digestion?

A)sugar (in the dressing)
B)oil (in the dressing)
C)starch (in the croutons)
D)cellulose (in the lettuce leaves)
E)protein (in the bacon bits)

Question 43

The figure below has a majority of which of the following:

A)carbohydrates
B)nucleotides
C)proteins
D)phospholipids
E)amino acids

Question 44

Chitin is a polysaccharide with __________ atoms attached to the glucose backbone.

A)magnesium
B)phosphorus
C)potassium
D)nitrogen
E)sulfur

Question 45

Which of the following is NOT true of polysaccharides?

A)composed of many linked monosaccharides
B)may be straight and unbranched or highly branched
C)most likely made of glucose molecules if they are one of the natural polysaccharides
D)may be insoluble because of their large size and structure
E)are formed by cleavage reactions

Question 46

Which is a monosaccharide?

A)glucose
B)chitin
C)amylose
D)starch
E)glycogen

Question 47

In the figure below, the object on which the bee is standing, has a majority of which of the following:

A)carbohydrates
B)nucleotides
C)proteins
D)lipids
E)amino acids

Question 48

Steroids

A)have no fatty-acid component.
B)consist of four rings.
C)may have different numbers, types, and positions of functional groups attached to them.
D)are a specialized type of lipid.
E)are all of these.

Question 49

Cellulose is

A)a polysaccharide found in cell walls.
B)a component of cell membranes.
C)an oligosaccharide.
D)formed by hydrolysis of monosaccharides.
E)a component of invertebrate exoskeletons.

Question 50

Which of the following are lipids?

A)sterols
B)triglycerides
C)oils
D)waxes
E)all of these

Question 51

Which of the following does not belong?

A)phospholipids
B)polysaccharides
C)unsaturated fats
D)steroids
E)saturated fats

Question 52

The dotted areas in the figure below indicate where __________ reactions will occur to produce __________ and __________.

A)condensation; covalent bonds; hydroxyl ions
B)electron transfer; covalent bonds; water molecules
C)condensation; covalent bonds; water molecules
D)cleavage; covalent bonds; hydrogen ions
E)condensation; ionic bonds; hydrogen ions

Question 53

Which of the following includes all the others?

A)sucrose
B)glucose
C)cellulose
D)glycogen
E)carbohydrate

Question 54

Like other animals, penguins of the north can keep warm because of layers and patches of __________ in their bodies.

A)adipose tissue
B)proteins
C)carbohydrates
D)sterols
E)phospholipids

Question 55

Which of the following does NOT describe some aspect of polysaccharides?

A)energy storage
B)straight or branched chain
C)glucose subunits
D)contain only carbon, hydrogen, and oxygen atoms
E)produced by condensation reactions

Question 56

Which carbohydrate is used to strengthen the shell of crabs?

A)glucose
B)lactose
C)glycogen
D)amylose
E)chitin

Question 57

Oils are

A)liquid at room temperatures.
B)unsaturated fats.
C)found only in animals.
D)complex carbohydrates.
E)both liquid at room temperature and unsaturated fats.

Question 58

Cholesterol

A)has a rigid backbone of four carbon rings.
B)is the most common sterol in animal tissue.
C)is a lipid without a fatty-acid component.
D)is needed to produce sexual development and maturity.
E)is all of these.

Question 59

Glycogen is a polysaccharide used for energy storage by

A)animals.
B)plants.
C)protistans.
D)bacteria.
E)fungi.

Question 60

Triglycerides are

A)carbohydrates.
B)nucleotides.
C)proteins.
D)neutral fats.
E)amino acids.

Question 61

Cholesterol can be remodeled into

A)bile salts.
B)sex hormones.
C)steroids.
D)vitamin D.
E)all of these.

Question 62

__________ are the main components of cell membranes.

A)Triglycerides
B)Phospholipids
C)Unsaturated fats
D)Steroids
E)Fatty acids

Question 63

Cholesterol is

A)synthesized in the large intestine.
B)remodeled into vitamin A.
C)used in the construction of cell membranes.
D)a component of plant cell walls.
E)all of these.

Question 64

The secondary structure of proteins may take the form of

A)twists.
B)bends.
C)loops.
D)folds.
E)all of these.

Question 65

Proteins may function as

A)structural units.
B)hormones.
C)storage molecules.
D)transport molecules.
E)all of these.

Question 66

Amino acids are linked by what kind of bonds to form the primary structure of a protein?

A)disulfide
B)hydrogen
C)ionic
D)peptide
E)none of these

Question 67

A single protein strand folded into a stable, functional domain represents

A)primary structure.
B)secondary structure.
C)tertiary structure.
D)quaternary structure.
E)most macromolecules.

Question 68

Lipids

A)yield less energy per gram than do carbohydrates.
B)include cartilage and chitin.
C)include fats consisting of one fatty-acid molecule and three glycerol molecules.
D)are composed of monosaccharides.
E)are none of these.

Question 69

The interaction of several polypeptide chains in a hemoglobin molecule is its __________ structure.

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

Question 70

The sixth amino acid in normal hemoglobin is glutamate, but it is replaced by __________ in sickle-cell anemia.

A)histidine
B)proline
C)leucine
D)valine
E)threonine

Question 71

The figure below illustrates one possible __________ structure of __________.

A)primary; proteins
B)primary; carbohydrates
C)primary; lipids
D)secondary; proteins
E)tertiary; proteins

Question 72

The region of the amino acid molecule that determines the specific amino acid is the

A)amine group.
B)carboxyl group.
C)backbone.
D)hydroxyl group.
E)"R" group.

Question 73

All steroids have

A)the same number of double bonds.
B)one or more fatty acids.
C)four rings of carbon to which other atoms are attached.
D)the same functional groups.
E)the same number and positions of double bonds.

Question 74

Amino acids in a polypeptide are part of

A)the primary structure.
B)carbohydrates.
C)lipids.
D)nucleic acids.
E)most macromolecules.

Question 75

Primary protein structure is formed by

A)hydrophobic interactions.
B)hydrogen bonds.
C)bonds between amino acids.
D)covalent linkages between carbon and oxygen.
E)all of these.

Question 76

Polyunsaturated fats

A)have fewer hydrogen atoms than do saturated fats.
B)are more characteristic of animal fats than plant fats.
C)have no double bonds.
D)are solid at room temperature.
E)are none of these.

Question 77

Amino acids are the building blocks for

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

Question 78

_____ are long-chain fatty acids attached to long-chain alcohols.

A)Triglycerides
B)Phospholipids
C)Sterols
D)Waxes
E)Most neutral fats

Question 79

The sequence of amino acids is the __________ structure of proteins.

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

Question 80

What kind of bond exists between two amino acids in a protein?

A)peptide
B)ionic
C)hydrogen
D)amino
E)sulfhydroxyl