Question 1

Enzymes are

Accepted Answer

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

Question 2

The R groups of amino acids located on the surface of protein molecules in the interior of biological membranes would be

Accepted Answer

A)  hydrophobic. 
B)  hydrophilic. 
C)  polar. 
D)  able to form disulfide. 
E)  electrically charged. 
A)  hydrophobic. 
B)  hydrophilic. 
C)  polar. 
D)  able to form disulfide. 
E)  electrically charged.

Question 3

All amino acids have a hydrogen atom, an amino group, and a _______ group.

Accepted Answer

The answer of All amino acids have a hydrogen atom,...

Question 4

Which of the following statements related to protein structure is false?

Accepted Answer

A)  Chaperones may assist in folding proteins. 
B)  Most of the interactions that stabilize folded proteins are covalent. 
C)  $\alpha$-Helical and $\beta$-sheets are common secondary structures in proteins. 
D)  Proper folding is essential to the function of a protein. 
E)  Some proteins contain more than one polypeptide chain. 
A)  Chaperones may assist in folding proteins. 
B)  Most of the interactions that stabilize folded proteins are covalent. 
C)  $\alpha$-Helical and $\beta$-sheets are common secondary structures in proteins. 
D)  Proper folding is essential to the function of a protein. 
E)  Some proteins contain more than one polypeptide chain.

Question 5

Dietary guidelines encourage people to stay away from saturated fats. What is meant by the term "saturated fat"? Why is this type of fat of more concern than unsaturated fats in the diet? What is the structural difference between saturated and unsaturated fats?

Accepted Answer

Saturated fats contain only single bonds

Question 6

Starch and glycogen, which are both polysaccharides, differ in their functions in that starch is _______, whereas glycogen _______.

Accepted Answer

A)  the main component for plant structural support; is an energy source for animals 
B)  a structural material found in plants and animals; forms external skeletons in animals 
C)  the principle energy storage compound of plants; is the main energy storage of animals 
D)  a temporary compound used to store glucose; is a highly stable compound that stores complex lipids 
E)  is the main energy storage of animals; a temporary compound used to store glucose 
A)  the main component for plant structural support; is an energy source for animals 
B)  a structural material found in plants and animals; forms external skeletons in animals 
C)  the principle energy storage compound of plants; is the main energy storage of animals 
D)  a temporary compound used to store glucose; is a highly stable compound that stores complex lipids 
E)  is the main energy storage of animals; a temporary compound used to store glucose

Question 7

Unsaturated fatty acids do not pack together due to

Accepted Answer

A)  kinks in the hydrocarbon-chain ribozymes. 
B)  glycosidic linkage proteases. 
C)  peptide-bond chaperonins. 
D)  disulfide bridges. 
E)  van der Waals-force triglycerides. 
A)  kinks in the hydrocarbon-chain ribozymes. 
B)  glycosidic linkage proteases. 
C)  peptide-bond chaperonins. 
D)  disulfide bridges. 
E)  van der Waals-force triglycerides.

Question 8

Maltose and lactose are similar in that they both are

Accepted Answer

A)  simple sugars. 
B)  amino acids. 
C)  insoluble in water. 
D)  disaccharides. 
E)  hexoses. 
A)  simple sugars. 
B)  amino acids. 
C)  insoluble in water. 
D)  disaccharides. 
E)  hexoses.

Question 9

You have isolated an unidentified liquid from a sample of beans. 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 large biological molecules does the unknown liquid most likely belong?

Accepted Answer

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

Question 10

The fluidity and melting point of fatty acids are partially determined by the number of _______ bonds.

Accepted Answer

unsaturate

Question 11

During the formation of a peptide linkage, a(n) _______ is formed.

Accepted Answer

A)  molecule of water 
B)  disulfide bridge 
C)  hydrophobic bond 
D)  hydrophilic bond 
E)  ionic bond 
A)  molecule of water 
B)  disulfide bridge 
C)  hydrophobic bond 
D)  hydrophilic bond 
E)  ionic bond

Question 12

There are a number of functional groups in biological molecules. Which of the following statements about their presence in different classes of molecules is most accurate?

Accepted Answer

A)  Hydroxyl groups are only present in carbohydrates. 
B)  Aldehyde groups are common in proteins. 
C)  Amino groups may be found in modified carbohydrates as well as in proteins. 
D)  Carboxyl groups are found only in small molecules. 
E)  Sulfhydryl groups are common in fats. 
A)  Hydroxyl groups are only present in carbohydrates. 
B)  Aldehyde groups are common in proteins. 
C)  Amino groups may be found in modified carbohydrates as well as in proteins. 
D)  Carboxyl groups are found only in small molecules. 
E)  Sulfhydryl groups are common in fats.

Question 13

Amino acids can be classified by the

Accepted Answer

A)  number of monosaccharides they contain. 
B)  number of carbon-carbon double bonds in their fatty acids. 
C)  number of peptide bonds they can form. 
D)  number of disulfide bridges they can form. 
E)  characteristics of their side chains, or "R" groups. 
A)  number of monosaccharides they contain. 
B)  number of carbon-carbon double bonds in their fatty acids. 
C)  number of peptide bonds they can form. 
D)  number of disulfide bridges they can form. 
E)  characteristics of their side chains, or "R" groups.

Question 14

Lipids are

Accepted Answer

A)  insoluble in water. 
B)  important for energy storage. 
C)  hydrophobic. 
D)  important constituents of biological membranes. 
E)  All of the above 
A)  insoluble in water. 
B)  important for energy storage. 
C)  hydrophobic. 
D)  important constituents of biological membranes. 
E)  All of the above

Question 15

Where would the leucine side chain most likely be found in a protein dissolved in water?

Accepted Answer

A)  In the interior of the protein in contact with nonpolar side chains 
B)  In the interior of the protein in contact with polar side chains 
C)  On the exterior of the protein 
D)  In the interior of the protein in contact with water 
E)  Either on the interior or exterior of the protein 
A)  In the interior of the protein in contact with nonpolar side chains 
B)  In the interior of the protein in contact with polar side chains 
C)  On the exterior of the protein 
D)  In the interior of the protein in contact with water 
E)  Either on the interior or exterior of the protein

Question 16

Cholesterol is soluble in ether, an organic solvent, but it is not soluble in water. Based on this information, to which class of biological macromolecules does cholesterol belong?

Accepted Answer

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

Question 17

The quaternary structure of a protein

Accepted Answer

A)  consists of four subunits-hence the name quaternary. 
B)  is unrelated to the function of the protein. 
C)  may be either alpha or beta. 
D)  depends on covalent bonding among the subunits. 
E)  depends on the primary structures of the subunits. 
A)  consists of four subunits-hence the name quaternary. 
B)  is unrelated to the function of the protein. 
C)  may be either alpha or beta. 
D)  depends on covalent bonding among the subunits. 
E)  depends on the primary structures of the subunits.

Question 18

Why does a starchy food, like bread, become hard and stale when it dries out?

Accepted Answer

A)  Cellulose molecules aggregate in the absence of water. 
B)  In the absence of water, unbranched starch forms hydrogen bonds between polysaccharides, which then aggregate. 
C)  The release of carbon dioxide causes the bread to harden. 
D)  Water and heat cause the polysaccharide chains to bind together. 
E)  Mold growth interferes with $\alpha$ linkages, causing the bread to harden. 
A)  Cellulose molecules aggregate in the absence of water. 
B)  In the absence of water, unbranched starch forms hydrogen bonds between polysaccharides, which then aggregate. 
C)  The release of carbon dioxide causes the bread to harden. 
D)  Water and heat cause the polysaccharide chains to bind together. 
E)  Mold growth interferes with $\alpha$ linkages, causing the bread to harden.

Question 19

The monomers that make up polymeric carbohydrates like starch are called

Accepted Answer

A)  nucleotides. 
B)  trisaccharides. 
C)  monosaccharides. 
D)  nucleosides. 
E)  fatty acids. 
A)  nucleotides. 
B)  trisaccharides. 
C)  monosaccharides. 
D)  nucleosides. 
E)  fatty acids.

Question 20

The side chain of leucine is a hydrocarbon. In a folded protein, where would you expect to find leucine?

Accepted Answer

A)  In the interior of a cytoplasmic enzyme 
B)  On the exterior of a protein embedded in a membrane 
C)  On the exterior of a cytoplasmic enzyme 
D)  Both a and b 
E)  Both a and c 
A)  In the interior of a cytoplasmic enzyme 
B)  On the exterior of a protein embedded in a membrane 
C)  On the exterior of a cytoplasmic enzyme 
D)  Both a and b 
E)  Both a and c

Exam 3: Proteins, Carbohydrates, and Lipids

Enzymes are

The R groups of amino acids located on the surface of protein molecules in the interior of biological membranes would be

All amino acids have a hydrogen atom, an amino group, and a _______ group.

Which of the following statements related to protein structure is false?

Dietary guidelines encourage people to stay away from saturated fats. What is meant by the term "saturated fat"? Why is this type of fat of more concern than unsaturated fats in the diet? What is the structural difference between saturated and unsaturated fats?

Starch and glycogen, which are both polysaccharides, differ in their functions in that starch is _______, whereas glycogen _______.

Unsaturated fatty acids do not pack together due to

Maltose and lactose are similar in that they both are

You have isolated an unidentified liquid from a sample of beans. 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 large biological molecules does the unknown liquid most likely belong?

The fluidity and melting point of fatty acids are partially determined by the number of _______ bonds.

During the formation of a peptide linkage, a(n) _______ is formed.

There are a number of functional groups in biological molecules. Which of the following statements about their presence in different classes of molecules is most accurate?

Amino acids can be classified by the

Lipids are

Where would the leucine side chain most likely be found in a protein dissolved in water?

Cholesterol is soluble in ether, an organic solvent, but it is not soluble in water. Based on this information, to which class of biological macromolecules does cholesterol belong?

The quaternary structure of a protein

Why does a starchy food, like bread, become hard and stale when it dries out?

The monomers that make up polymeric carbohydrates like starch are called

The side chain of leucine is a hydrocarbon. In a folded protein, where would you expect to find leucine?

Studying Life

Small Molecules and the Chemistry of Life

Nucleic Acids and the Origin of Life

Cells: the Working Units of Life

Cell Membranes

Cell Signaling and Communication

Energy, Enzymes, and Metabolism

Pathways That Harvest Chemical Energy

Photosynthesis: Energy From Sunlight

The Cell Cycle and Cell Division

Inheritance, Genes, and Chromosomes

Dna and Its Role in Heredity

From Dna to Protein: Gene Expression

Gene Mutation and Molecular Medicine

Regulation of Gene Expression

Genomes

Recombinent Dna and Biotechnology

Differential Gene Expression in Development

Development and Evolutionary Change

Evidence and Mechanisms of Evolution

Reconstructing and Using Phylogenies

Species and Their Formation

Evolution of Genes and Genomes

The History of Life on Earth

Bacteria and Archaea: the Prokaryotic Domains

The Origin and Diversification of Eukaryotes

Plants Without Seeds: From Water to Land

The Evolution of Seed Plants

Fungi: Recyclers, Pathogens, Parasites, and Plant Partners

Animal Origins and the Evolution of Body Plans

Protostome Animals

Deuterostome Animals

The Plant Body

Transport in Plants

Plant Nutrition

Regulation of Plant Growth

Reproduction in Flowering Plants

Plant Responses to Environmental Challenges

Physiology, Homeostasis, and Temperature Regulation

Animal Hormones

Immunology: Animal Defense Systems

Animal Reproduction

Animal Development

Neurons and Nervous Systems

Sensory Systems

The Mammalian Nervous System: Structure and Higher Function

Musculoskeletal Systems

Gas Exchange in Animals

Circulatory Systems

Nutrition, Digestion, and Absorption

Salt and Water Balance and Nitrogen

Animal Behavior

Ecology and the Distribution of Life

Population Ecology

Species Interaction and Coevolution

Community Ecology

Ecosystems and Global Ecology

Conservation Biology

Filters

Starch and glycogen, which are both polysaccharides, differ in their functions in that starch is _, whereas glycogen _.