Question 1

Which property of carbon is most responsible for the diversity of organic molecules found in living organisms?

Accepted Answer

Its tetravalency, allowing it to form four covalent bonds with other atoms

Question 2

Why are hydrocarbons generally insoluble in water?

Accepted Answer

They lack polar functional groups and cannot form hydrogen bonds with water

Question 3

Which of the following best explains why visible light does not break the covalent bonds in organic molecules?

Accepted Answer

Visible light has a longer wavelength and therefore less energy than the bond energy of C—C bonds

Question 4

A molecule with the formula $$C_6H_{12}O_6$ contains several asymmetric carbon atoms. How many stereoisomers are possible if it has 4 asymmetric carbons?

Accepted Answer

$$2^4 = 16$

Question 5

Which functional group is most likely to confer a negative charge to a biological molecule at neutral pH?

Accepted Answer

Carboxyl group

Question 6

Which property of water is primarily responsible for its ability to moderate temperature changes in living organisms?

Accepted Answer

High specific heat

Question 7

What is the main reason ions such as $$Na^+$$ and $$Cl^-$$ cannot freely cross the lipid bilayer of a cell membrane?

Accepted Answer

They are surrounded by a hydration shell and repelled by the hydrophobic interior

Question 8

Which of the following statements about the synthesis of biological macromolecules is correct?

Accepted Answer

Monomers must be activated by attachment to a carrier molecule before polymerization

Question 9

Which type of bond or interaction is primarily responsible for the secondary structure of proteins?

Accepted Answer

Hydrogen bonds

Question 10

A protein is denatured by heat but regains its function when cooled. What does this demonstrate about protein structure?

Accepted Answer

The information for folding is inherent in the amino acid sequence

Question 11

Which of the following best describes the amphipathic nature of membrane phospholipids?

Accepted Answer

They have both a polar head and two nonpolar hydrocarbon tails

Question 12

Which process is responsible for the movement of water across a cell membrane in response to solute concentration differences?

Accepted Answer

Osmosis

Question 13

Which of the following is NOT a property of water that is critical for life?

Accepted Answer

Low specific heat

Question 14

Which of the following statements about self-assembly in biological systems is correct?

Accepted Answer

The information for assembly is inherent in the structure of the molecules involved

Question 15

Which of the following interactions is the weakest but still important in stabilizing macromolecular structures?

Accepted Answer

Van der Waals interactions

Question 16

Which of the following best explains why biological membranes are selectively permeable?

Accepted Answer

Their hydrophobic interior prevents passage of most polar molecules and ions

Question 17

Which of the following is a real-world example of hierarchical assembly in cells?

Accepted Answer

Formation of a protein from amino acids, then assembly of ribosomes from proteins and rRNA

Question 18

Which of the following statements about polysaccharides is true?

Accepted Answer

Polysaccharides are typically structural or storage macromolecules

Question 19

Which of the following best describes the role of molecular chaperones in protein folding?

Accepted Answer

They assist in correct folding by preventing unproductive assembly pathways

Question 20

Which of the following is an example of a condensation reaction in biological systems?

Accepted Answer

The formation of a peptide bond between two amino acids with the release of water

The Chemistry of the Cell: Principles and Foundations

Study Guide - Practice Questions

Study Guide - Flashcards