Deck 3: The Chemical Basis of Life II: Organic Molecules

Question 1

Which of the following is an important feature of carbon and that makes life possible?

A) Carbon can form a maximum of 8 covalent bonds.
B) Carbon can form a maximum of 6 covalent bonds.
C) Carbon can form a maximum of 4 covalent bonds.
D) Carbon can form a maximum of 2 covalent bonds.
E) None of the choices are possible for carbon.

Answer 1

Carbon can form a maximum of 4 covalent bonds.

Question 2

Which of the following are important features of carbon and the diversity of organic molecules?

A) Carbon can form up to 4 covalent bonds with other elements.
B) Carbon bonds may occur in multiple different configurations such as linear, ringlike, and highly branched.
C) Carbon can form both polar and nonpolar covalent bonds with various elements.
D) Carbon bonds are stable at the range of temperatures associated with life.
E) All the choices are correct.

Answer 2

All the choices are correct.

Question 3

Which of the following molecules is nonpolar?

A) C₂H₅COOH
B) C₂H₆
C) R-NH₂
D) C₃H₇OH
E) C₅H₁₀O₅

Answer 3

C₂H₆

Question 4

Two molecules with identical molecular formulas but that have different structures are called

A) polymers.
B) isomers.
C) carboyhydrates.
D) hydrocarbons.
E) ring structures.

Question 5

Which of the following has identical molecular formulas but different structures and characteristics?

A) isomers
B) sterioisomers
C) enantiomers
D) isomers, but not sterioisomers
E) isomers, sterioisomers, and enantiomers

Question 6

Organic molecules with identical molecular formulas and that are structurally mirror images of each other are most specifically referred to as

A) polymers.
B) mimics.
C) enantiomers.
D) hydrocarbon rings.
E) saturated fatty acids.

Question 7

Which functional group forms covalent bonds and contributes to tertiary structure of proteins?

A) NH₂
B) COOH
C) PO₄
D) SH
E) OH

Question 8

Which of the following macromolecules are polymers?

A) lipids
B) carboyhydrates
C) nucleic acids
D) proteins
E) All of the choices are correct.

Question 9

All are true about a dehydration reaction EXCEPT which of the following?

A) Results in removal of a water molecule.
B) Essential for the breakdown of complex molecules to simple ones.
C) Essential to the formation of polymers.
D) Essential for the formation of glycogen from glucose monomers.
E) Essential for the formation of triglycerides (fat) from glycerol and fatty acids.

Question 10

A monomer is to a polymer, as glucose is to

A) lipids.
B) carboyhydrates.
C) nucleic acids.
D) proteins.
E) None of the choices are correct.

Question 11

Which of these is NOT a lipid?

A) phospholipid
B) cholesterol
C) steroids
D) glycogen
E) wax and oils

Question 12

Which of the following is NOT a property of fat or of fatty acids?

A) They are soluble in water.
B) The source of variation in fat molecules is the fatty acid composition.
C) Fatty acids can vary in number and location of C-C double bonds.
D) Fatty acids may vary in length.
E) Fats can be liquid or solid at room temperature, depending on fatty acid composition.

Question 13

Which is TRUE about amphipathic molecules when placed in an aqueous solution?

A) The interior portion is composed of hydrophilic hydrocarbon chains.
B) The outside portion is composed of hydrophilic head groups.
C) The interior portion is composed of hydrophobic hydrocarbon chains.
D) The interior portion of the micelle is composed of hydrophilic hydrocarbon chains and the outside portion of hydrophilic head groups.
E) The interior portion is composed of hydrophobic hydrocarbon chains and the outside portion of hydrophilic head groups.

Question 14

This class of macromolecules serves as important energy stores and is a major component of plasma membranes.

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

Question 15

Which of the molecules below is NOT a subunit for building macromolecules?

A) glucose
B) amino acids
C) steroid
D) fatty acid
E) nucleotides

Question 16

What is the main difference between a fat (triglyceride) and a phospholipid?

A) A fat has 4 fatty acids attached to glycerol, whereas a phospholipid has 3.
B) A fat has 3 fatty acids attached to glycerol, whereas a phospholipid has 4.
C) A phospholipid has 2 fatty acids attached to glycerol, whereas a fat has 3.
D) A phospholipid has 3 fatty acids attached to glycerol, whereas a fat has 2.
E) None of the above are True.

Question 17

With regard to protein structure, which level determines all others?

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

Question 18

What level of protein structure, characterized by coils and folds, results from hydrogen bonding between carboxyl and amino groups of the polypeptide chain?

A) primary
B) secondary
C) tertiary
D) quaternary
E) both secondary and quaternary

Question 19

Which portion of an amino acid is unique among the different amino acids?

A) carboxyl
B) amino
C) hydrocarbon
D) the side chain or R-group
E) peptide bonding

Question 20

Which macromolecule has the highest diversity of functions?

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

Question 21

The tertiary structure of a protein is dependent on

A) the side chain composition of each amino acid within the protein.
B) hydrogen bonding between the carboxyl and amino groups within the polypeptide chain.
C) the interactions of multiple polypeptide chains that make up a functional protein.
D) the way in which the peptide bond forms.
E) the degree through which the dehydration reaction occurs.

Question 22

Which is true of the nucleotide base composition within the DNA double helix?

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

Question 23

If a specimen contains 30% adenine in its DNA then how much cytosine will there be?

A) 40%
B) 30%
C) 20%
D) 10%
E) Cannot be determined.

Question 24

An amino acid is to a protein as a ________ is to a nucleic acid.

A) glucose
B) glycerol
C) nucleotide
D) fatty acid
E) cellulose

Question 25

Which is true of the base pairing seen between two DNA strands?

A) Adenine bonds with guanine.
B) Guanine bonds with thymine
C) Thymine bonds with cytosine
D) Cytosine bonds with guanine
E) Guanine bonds with thymine.

Question 26

Friedrich Wö hler refuted the scientific concept of vitalism during the early 1800s by proving that organic molecules could be synthesized outside a living organism.

Question 27

Macromolecules such as lipids and carbohydrates are produced from simple subunits through condensation reactions.

Question 28

Lipids and carbohydrates have similar functions insofar as they can represent a form of energy store in animals.

Question 29

When a food label reads polyunsaturated fats, this refers to fatty acids composed of multiple double bonded carbons.

Question 30

The four nucleotide bases found in DNA are identical to those in RNA.