Question 1

Which of the following best explains why water is an effective solvent for ionic compounds such as NaCl?

Accepted Answer

Water molecules have partial charges that interact with the positive and negative ions, forming hydration spheres.

Question 2

Which of the following statements about phospholipids in biological membranes is correct?

Accepted Answer

Phospholipids have both hydrophilic and hydrophobic regions, resulting in a bilayer that is selectively permeable.

Question 3

Which type of chemical bond is primarily responsible for the stability of double-stranded DNA?

Accepted Answer

Hydrogen bonds between complementary base pairs

Question 4

A molecule with the formula $$\mathrm{C$$_{16}$$H_{32}O_2$} is $$most likely which type of biomolecule?

Accepted Answer

Lipid (fatty acid)

Question 5

Which of the following best describes the difference between covalent and ionic bonds in biomolecules?

Accepted Answer

Covalent bonds involve the sharing of electrons, while ionic bonds involve the transfer of electrons.

Question 6

Which of the following functional groups is hydrophilic and negatively charged at neutral pH?

Accepted Answer

Carboxyl group ($$-\mathrm{COOH})$$

Question 7

A scientist is studying a cell line that can grow indefinitely in culture. Which type of cell is most likely being studied?

Accepted Answer

HeLa cell

Question 8

Which of the following is a consequence of the amphipathic nature of membrane lipids?

Accepted Answer

Membranes form bilayers with hydrophobic tails facing inward and hydrophilic heads facing outward.

Question 9

Which of the following best describes the role of van der Waals interactions in biomolecules?

Accepted Answer

They are weak, transient forces that contribute to the folding and stability of macromolecules.

Question 10

Which of the following statements about water is correct?

Accepted Answer

Water is a polar molecule with partial negative charge on oxygen and partial positive charges on hydrogens.

Question 11

Which of the following is true regarding the formation of polymers from monomers?

Accepted Answer

Polymers are formed by stepwise reactions called polymerization, joining monomers together.

Question 12

Which of the following best explains why hydrocarbons are hydrophobic?

Accepted Answer

Hydrocarbons have nonpolar covalent bonds and do not interact favorably with water.

Question 13

Which of the following is a correct statement about stereoisomers in biomolecules?

Accepted Answer

Stereoisomers are molecules with the same chemical formula but different spatial arrangements, often due to the presence of a chiral carbon.

Question 14

Which of the following bonds is most likely to be broken when NaCl dissolves in water?

Accepted Answer

Ionic bonds between Na$$^+$$ and Cl$$^-$$ ions

Question 15

Which of the following is NOT a major element found in biomolecules?

Accepted Answer

Sodium

Question 16

Which of the following best describes the role of hydrogen bonds in water?

Accepted Answer

Hydrogen bonds allow water molecules to interact, giving water its high boiling point and surface tension.

Question 17

Which of the following is a correct application of the concept of selective permeability in biological membranes?

Accepted Answer

Small nonpolar molecules can pass through the membrane easily, while large polar molecules cannot.

Question 18

Which of the following is a real-world example of the importance of covalent bonds in biomolecules?

Accepted Answer

The formation of peptide bonds between amino acids in proteins

Question 19

Which of the following best explains the importance of functional groups in biomolecules?

Accepted Answer

Functional groups determine the chemical reactivity and properties of biomolecules.

Question 20

Which of the following is a correct statement about the stability of bonds in biological molecules?

Accepted Answer

Triple bonds are generally more stable than double or single bonds due to greater electron sharing.

Fundamental Concepts in Cell Biology: Structure, Chemistry, and Biomolecular Interactions

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