Deck 3: The Organic Molecules of Life

Question 1

A polypeptide forms a pleated sheet or a helix as its primary structure.

Answer 1

False
Explanation: The secondary folding of a polypeptide produces two shapes depending on the number and type of amino acids present in the chain. They can either have a spiral shape helix) or a folded shape pleated sheet).

Question 2

Scientists created an enzyme that will break down any type of carbohydrate. If given to humans, they could use which of the following as a new food source?

A) glucose
B) glycerol
C) cellulose
D) cholesterol
E) protein Cellulose is a polysaccharide with bond linkages that are undigestable by humans. The digestive enzymes of animals are unable to hydrolyze cellulose.

Answer 2

C

Question 3

Refer to the figure. Which of the following is true regarding the labeled plasma membrane?

A) Parts X and Z are hydrophobic.
B) Parts W and Z are hydrophilic.
C) Parts X and Y are hydrophilic.
D) Parts W and Y are hydrophobic.
E) Parts W and X are hydrophilic. The hydrophilic polar head portion of a phospholipid is found on the outside margins closest to water exposure. The hydrophobic nonpolar tail portions are found on the inside of the membrane as far from water as possible.

Answer 3

B

Question 4

A gene in DNA is the code for assembling a sequence of

A) amino acids.
B) glucose molecules.
C) fatty acids used in a fat.
D) sugars.
E) functional groups. A gene is a series of nucleotides that codes for a specific sequence of amino acids to be assembled into a polypeptide.

Question 5

Select the incorrect association.

A) glucose - monosaccharide
B) cellulose - building block for cell walls in plants
C) sucrose - table sugar
D) fructose - a polysaccharide
E) starch - a long chain of glucose Fructose is a monosaccharide. Polysaccharides include materials such as cellulose, starch, and glycogen.

Question 6

Select the incorrect association.

A) carbohydrates-provide the body with energy
B) lipids-serve to insulate, protect, and store energy
C) proteins-have three forms: monosaccharides, disaccharides, and polysaccharides
D) nucleic acids-include DNA and RNA, which control our genetic inheritance
E) carbohydrates-include glucose, sucrose, and starch Monosaccharides, disaccharides, and polysaccharides are all categories of carbohydrates, not forms of proteins.

Question 7

When starch is digested, an -OH group and an -H group from a water molecule is used in hydrolysis to split the monosaccharide subunits.

Question 8

Wood and cotton cloth are composed of

A) chitin.
B) cellulose.
C) glycogen.
D) cholesterol.
E) lipid. Plant cell walls contain cellulose and therefore it will be found in any plants or plant products.

Question 9

Which word does not belong with the others?

A) muscle
B) antibodies
C) sucrose
D) enzymes
E) hair Sucrose is a type of disaccharide carbohydrate. Muscle, antibodies, hair, and enzymes are all substances made of protein.

Question 10

Testosterone is a lipid-based hormone; insulin is a ________-based hormone.

A) saccharide
B) protein
C) steroid
D) carbohydrate
E) nucleic acid Insulin is a regulatory protein comprised of long chains of amino acids.

Question 11

Hydrolysis of sucrose, a disaccharide, results in

A) two monomers.
B) the release of functional groups.
C) three monosaccharides.
D) two glycerol units.
E) two nucleotides. Sucrose is a disaccharide that when broken down by hydrolysis reactions results in two monosaccharide units.

Question 12

A triglyceride is formed when three fatty acids join a glycerol by a

A) hydrolysis reaction.
B) dehydration reaction.
C) polymeric reaction.
D) digestive reaction.
E) evaporation reaction. When glycerol and three fatty acids join to form a fat, three water molecules also form as a product. This is known as a dehydration synthesis reaction.

Question 13

In sickle-cell disease, malformation of red blood cells is caused by only one mistake for one amino acid in the genetic code for hemoglobin.

Question 14

Which word does not belong with the others?

A) fats
B) steroids
C) glycogen
D) phospholipids
E) lipids Glycogen is a polysaccharide, but the other choices are all types of lipids.

Question 15

Which of the following is not a dehydration synthesis reaction?

A) amino acids forming proteins
B) glycogen forming glucose molecules
C) nucleotides forming DNA
D) glucose units forming starch
E) fatty acids and glycerol forming a fat

Question 16

Which of the following correctly lists the parts of a nucleotide of RNA?

A) nitrogen-containing base, deoxyribose, phosphate
B) sulfur-containing base, ribose, phosphate
C) nitrogen-containing base, ribose, phosphate
D) nitrogen-containing base, ribose, sulfur
E) amino acid, glycerol, nitrogen-containing base A nucleotide of any nucleic acid consists of a phosphate, sugar, and nitrogenous base.

Question 17

Which of the following is in correct order from smallest to largest?

A) peptide - amino acid - polypeptide
B) amino acid - polypeptide - peptide
C) amino acid - peptide - polypeptide
D) protein - glycerol - amino acid
E) disaccharide - polysaccharide - monosaccharide A peptide is two or more amino acids covalently bonded together, whereas a polypeptide is a chain of many amino acids joined together. When a polypeptide folds into a specific shape, it is then identified as a protein.

Question 18

Deoxyribose is a sugar found in

A) glucose.
B) enzymes.
C) DNA.
D) glycogen.
E) protein. The sugar deoxyribose is one portion of a nucleotide monomer that helps to create the biological molecule DNA.

Question 19

Which of the following is not associated with proteins?

A) Proteins are made up of amino acids bonded together.
B) Denaturation destroys proteins' shape and function.
C) Proteins are used to produce DNA.
D) Proteins are found in skin, nails, and claws.
E) Proteins are used to produce many types of hormones. DNA is made from nucleotide monomers. DNA is used to code for the specific amino acids to be sequenced to produce a protein.

Question 20

Atherosclerosis is associated with

A) fats with no double bonds.
B) fats with double bonds.
C) phospholipids.
D) polyunsaturated fats.
E) long protein chains. Saturated fats have no double bonds between the carbon atoms. They are linked to the promotion of a buildup of fat material known as plaque in a person's blood vessels in a disease known as atherosclerosis.

Question 21

Which formula is a hydrocarbon?

A) CO?₂
B) CH₄
C) NaCl
D) CaCl₂
E) H₂O Hydrocarbons are chains of carbon atoms that are joined to hydrogen atoms. Methane, CH₄, is the only representative in the choices provided.

Question 22

How are lipids different from other categories of biological molecules?

A) They are not seen in all living things.
B) They do not have carbon.
C) They are much more complex.
D) They will not combine with water.
E) They are not organic. Lipids are very diverse and have varied structures. None of the lipid types consist of repeated subunits as the other biological molecules. Lipids are hydrophobic molecules that do not readily mix with water.

Question 23

The four main categories of organic macromolecules are

A) monosaccharides, disaccharides, trisaccharides, and polysaccharides.
B) proteins, DNA, waxes, and sugars.
C) carbohydrates, lipids, proteins, and nucleic acids.
D) RNA, DNA, steroids, and fats.
E) lipids, starches, DNA, and protein.

Question 24

In the diagram below, the monomer that serves as the subunit to creating this organic molecule category is called

A) nucleotide.
B) phosphate.
C) sugar.
D) base.
E) glucose.

Question 25

The principle role for sugars in living things is to

A) form cell membranes.
B) serve as a form of long-term energy storage.
C) create our genetic code.
D) create cellular energy.
E) produce hormones. Carbohydrate sugars are used as an immediate energy source in living things.

Question 26

Which of the following levels of a protein are susceptible to denaturation?

A) primary and secondary structures
B) secondary and tertiary structures
C) tertiary and quaternary structures
D) primary and tertiary structures
E) primary and quaternary structures Denaturation by such things as pH and temperature cause the bonds which allow for tertiary and quaternary structures to be disrupted. When their folding is altered, the function of the protein is disrupted.

Question 27

Which of the following is not an organic molecule?

A) CaCO₃
B) C?₆H₁₂O₆
C) C₂₅₆H₃₈₁N₆₅O₇₉S₆
D) C₁₈H₃₄O₂
E) CH₄

Question 28

Which one of the following is a function of proteins?

A) energy storage
B) enzymatic activity
C) genetic coding
D) energy source
E) insulation

Question 29

Plants store their sugar in the form of

A) protein.
B) glycogen.
C) cellulose.
D) starch.
E) glucose. Plants store their glucose in the form of starch, a form that can then be drawn on as a reserve when needed.

Question 30

Humans store excess polysaccharides in the form of

A) lactose.
B) starch.
C) glycogen.
D) glucose.
E) cellulose. Glycogen is a type of polysaccharide used to store sugar in animals.

Question 31

When you eat a salad, which one of the following components will pass through the body with the least amount of digestion?

A) dressing
B) croutons
C) lettuce
D) egg
E) bacon bits The lettuce is comprised of the structural carbohydrate called cellulose. Humans lack the enzymes needed to break the bonds apart between monomers and are thus not able to digest this material.

Question 32

In a dehydration reaction, ________. In order for this to occur water is ________.

A) monomers are joined to become a polymer; removed
B) polymers are broken up to form monomers; added
C) monomers are broken up to form polymers; added
D) polymers are joined to form monomers; removed
E) polymers are broken up to form monomers; removed To synthesize any type of biological molecule, an -H atom and an -OH group are removed. It is called a dehydration reaction because the equivalent of water is removed as the reaction occurs.

Question 33

The figure below represents the formation of a ________ molecule by the process of ________.

A) glycogen; hydrolysis
B) DNA; dehydration synthesis
C) protein; hydrolysis
D) fat; dehydration synthesis
E) polysaccharide; hydrolysis The removal of water allows the carboxyl units of three fatty acids to bond to the OH^- groups of glycerol producing a fat molecule.

Question 34

Amino acids are needed to build ________, just as ________ are needed to create DNA.

A) protein; nucleotides
B) fatty acid; hydroxides
C) polysaccharides; carboxyl
D) RNA; glucose monomers
E) fats; sugars Amino groups are part of amino acid monomers which are the building blocks of proteins. Similarly, phosphate groups are a component of nucleotides which are the monomer building blocks to DNA molecules.

Question 35

Which of the following elements would be found in a carbohydrate?

A) C, H
B) C, H, O
C) C, H, O, P
D) C, H, O, N
E) C, H, Cl, O Carbohydrates are organic molecules comprised of the elements carbon, hydrogen, and oxygen.

Question 36

When a person orders a hamburger with lettuce, tomato, and mayonnaise, which of the following would be a false statement about the nutritional intake?

A) Amino acids can be obtained from the hamburger patty.
B) Glycogen will be obtained from the bun.
C) Fat will be consumed from the mayonnaise.
D) Cellulose will be consumed from the lettuce.
E) Carbohydrates will be obtained from the tomato. The bun is comprised of starch molecules. Glycogen would not be found in this food as it is a type of polysaccharide used to store sugars in animals.

Question 37

The following figure represents which process?

A) dehydration synthesis
B) denaturation
C) polyunsaturation
D) hydrolysis
E) combustion

Question 38

A starch molecule is to glucose as

A) a protein is to a polypeptide.
B) DNA is to an amino acid.
C) a lipid is to nucleic acid.
D) a protein is to an amino acid.
E) fatty acid is to a fat. Starch is a polymer and glucose is a monomer. This is the same case when comparing a protein to an amino acid.

Question 39

Glycogen is a ________ made of many ________.

A) simple sugar; amino acids
B) peptide; amino acids
C) polymer; glucose molecules
D) protein; fatty acids
E) nucleic acid; nucleotides Glycogen is a type of polysaccharide. It is a polymer comprised of repeated glucose units.

Question 40

Which of the following levels of protein folding would include shapes identified as helix and pleated sheet?

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

Question 41

Which of the following is least likely to be affected when a protein is denatured?

A) primary structure
B) secondary structure
C) tertiary structure
D) quaternary structure
E) the folded shape of the protein

Question 42

Which functional group is present in amino acids?

A) PO₄
B) -OH
C) -NH₂
D) -C=OH
E) -C-H -NH2, the monomer building block to protein production, is the functional group that is part of all amino acids.

Question 43

Of the following, which is a feature that proteins and polysaccharides share?

A) They are made of repeated monomer units.
B) They are both made from fatty acids.
C) They both contain glucose.
D) They are both long chains of repeated nucleotide units.
E) They both contain nitrogen. Proteins and carbohydrates both consist of repeated monomers.

Question 44

In which of the following is the correct monomer matched with its polymer?

A) fatty acid - DNA
B) monosaccharide - lipid
C) glycerol - carbohydrate
D) amino acid - protein
E) nucleotide - carbohydrate

Question 45

Which one of the following is not a potential danger of anabolic steroids?

A) can result in liver problems
B) can enhance the body's production of normal sex hormones
C) can cause mood swings and depression
D) can reduce sex drive
E) can result in heart problems Besides the destruction of heart and kidney function, anabolic steroids upset the normal hormonal balances in the body. As the levels of synthetic hormone are detected, the body suppresses the natural production of its sex hormones.

Question 46

What is the function of a peptide bond?

A) joins a sodium atom to a chloride atom
B) helps hold one water molecule to an adjacent one
C) links oxygen to hydrogen atoms
D) joins an amino acid to an adjacent amino acid
E) joins nucleotide bases to one another A peptide bond is a type of covalent bond that joins two amino acids together. This occurs by a dehydration reaction between the carboxyl group of one and the amino group of another.

Question 47

The term "functional" is used in the phrase "functional group" because it describes a group of atoms that

A) are organic.
B) make the entire molecule hydrophobic.
C) prevent interaction with other molecules.
D) react a certain way with other molecules.
E) make the entire molecule hydrophilic. Functional groups are specific combinations of bonded atoms that always have the same chemical properties, thus always reacting in the same way.

Question 48

The basic building block or subunit of many biological molecules is called an)

A) quaternary structure.
B) polymer.
C) monomer.
D) isomer.
E) chain. A monomer subunit is the building block to create long organic molecule chains called polymers.

Question 49

Which of the following is an organic molecule?

A) NaOH
B) HCl
C) CO₂
D) C₆H₁₂O₆
E) H₂O Organic molecules are those that contain both carbon and hydrogen and may contain a variety of other elements.

Question 50

The primary structure of a protein refers to the

A) interactions among two or more polypeptides.
B) alpha helix or pleated sheets.
C) side groups of the amino acids.
D) number and sequence of amino acids.
E) DNA nucleotide sequence that coded for it. The primary structure is comprised of the sequence of amino acids that have been joined together through peptide bonding.

Question 51

If a material mixes readily with water, it is identified as

A) dehydrated.
B) hydrophobic.
C) saturated.
D) hydrophilic.
E) salty. Hydrophilic means "water loving," which makes the material capable of dissolving in water.

Question 52

Which of the following would describe a polypeptide?

A) fatty acids joined to glycerol by hydrolysis reactions
B) glucose molecules joined by dehydration synthesis reactions
C) nucleotides broken by hydrolysis reactions
D) amino acids joined by dehydration synthesis reactions
E) a repeated sequence of carbon and hydrogen atoms

Question 53

What makes saturated triglycerides considerably less healthy than unsaturated ones?

A) They taste better than other fats.
B) They possess no double bonds between carbon atoms, which makes them more tightly packed together.
C) Individuals tend to consume more saturated fats than unsaturated fats.
D) Unsaturated fats are found in processed foods more frequently.
E) They are digested more quickly by the body. Saturated fats have no double bonds between the carbon atoms. This arrangement makes saturated fat molecules pack together more tightly and, consequently, more difficult to digest. If the fat molecule is not digested adequately, there is the danger of these lipids accumulating in blood vessels in the form of plaque. It is a leading cause of the cardiovascular disease known as atherosclerosis.

Question 54

A molecule is said to be organic if it contains

A) double bonds.
B) hydrogen bonds.
C) carbon and hydrogen atoms.
D) carbon and oxygen atoms.
E) two or more atoms.

Question 55

What functional group makes a carbohydrate polar?

A) -OH
B) -NH₂
C) -SH
D) -R
E) -C-H The -OH is a polar functional group because it is soluble in water hydrophilic).

Question 56

A nucleotide is made of which of the following chemical components?

A) a nitrogen-containing base, an amino acid, and a five-carbon sugar
B) a nitrogen-containing base, an amino acid, and a phosphate group
C) a nitrogen-containing base, a phosphate group, and a sugar
D) a nitrogen-containing base, a fatty acid, and an amino acid
E) a long chain of glucose units A nucleotide is comprised of a phosphate, 5 carbon sugar, and nitrogenous base.

Question 57

Which of the following is an organic molecule?

A) CO₂
B) H₂CO₃
C) Na₂CO₃
D) MnCO₃
E) CaCO₃ Organic molecules are those that contain both carbon and hydrogen and may contain a variety of other elements.

Question 58

A fatty acid that has at least two double bonds is called

A) steroid.
B) cholesterol.
C) unsaturated.
D) abonded.
E) organic.

Question 59

What category of biological molecules are steroids included in?

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

Question 60

How does DNA differ from RNA?

A) DNA is in plants; RNA is found in animals.
B) DNA is comprised of a double-strand; RNA is a single-strand.
C) DNA is made from amino acids; RNA is made from nucleotides.
D) DNA is used by all living things; RNA is used only in plants.
E) DNA is seen in animals; RNA is seen in all living things. DNA is a double strand of joined nucleotides, while RNA is a single strand of nucleotides. Both are found in all living things.

Question 61

DNA functions to ________, while RNA's function is to________.

A) store the information to make a new organism; contain the information to make a new cell.
B) store information to produce gametes; contain the information to make a protein.
C) store information to produce proteins; contain the information to make a DNA.
D) store the information to make RNA; contain the information to make a protein.
E) store information to produce a new protein; contain the information to make mRNA. DNA serves as the template to create RNA, which is then used to produce the proteins needed by the cell to function.

Question 62

Which functional group acts as an acid when placed in solution?

A) -OH
B) -NH₂
C) -SH
D) -COOH
E) -PO₄ The carboxyl group is found in amino acids and will donate a hydrogen ion to a solution resulting in the functional groups becoming -COO^- and increasing the acidity of the solution.

Question 63

Which nitrogen-containing base is found in RNA but not in DNA?

A) guanine
B) thymine
C) cytosine
D) adenine
E) uracil Uracil is found in RNA but is not found in DNA, while guanine, adenine, and cytosine are found in both.

Question 64

DNA and RNA differ in that

A) DNA is single-stranded and contains the sugar deoxyribose and the nitrogen-containing base thymine; RNA is double-stranded and contains sugar ribose and the nitrogen-containing base uracil.
B) DNA is double-stranded and contains the sugar deoxyribose and the nitrogen-containing base thymine; RNA is single-stranded and contains sugar ribose and the nitrogen-containing base uracil.
C) DNA is single-stranded and contains the sugar ribose and the nitrogen-containing base thymine; RNA is single-stranded and contains sugar deoxyribose and the nitrogen-containing base uracil.
D) DNA is single-stranded and contains the sugar deoxyribose and the nitrogen-containing base uracil; RNA is double-stranded and contains sugar ribose and the nitrogen-containing base thymine.
E) DNA is double-stranded and contains the sugar ribose and the nitrogen-containing base thymine; RNA is single-stranded and contains sugar deoxyribose and the nitrogen-containing base uracil. The structural differences between DNA and RNA allows the cell to distinguish between the two types of nucleic acids.

Question 65

Which of the following is not an organic molecule?

A) C₁₂H₉SO₃H
B) C₉H₁₃NO₃
C) C₁₀H₁₃N₅O₄
D) H₂NCH₂CN
E) COCl₂ Organic molecules are those that contain both carbon and hydrogen and may contain a variety of other elements.

Question 66

Which nitrogen-containing base is found in DNA but not in RNA?

A) guanine
B) thymine
C) cytosine
D) adenine
E) uracil Thymine is found in DNA but is not found in RNA, while guanine, adenine, and cytosine are found in both.

Question 67

ATP is a molecule used for energy transport inside the cell. The components of ATP are a nitrogen-containing base, a pentose sugar, and three phosphate groups. Given this structure, ATP is an)

A) amino acid.
B) carbohydrate.
C) lipid.
D) nucleic acid.
E) protein. ATP is a modified adenine that has three phosphate groups, but in other aspects ATP is the same as adenine.

Question 68

In addition to carbon, an organic molecule must contain

A) nitrogen.
B) oxygen.
C) hydrogen.
D) sulfur.
E) phosphorous. Organic molecules are those that contain both carbon and hydrogen.