Question 1

Which property of water is most directly responsible for the ability of some insects to walk on its surface?

Accepted Answer

High surface tension

Question 2

Why are carbon-carbon (C–C) bonds particularly suitable for forming the backbone of biological macromolecules?

Accepted Answer

They have high bond energy, making them stable under most cellular conditions.

Question 3

Which of the following functional groups is negatively charged at physiological pH and commonly found in nucleic acids?

Accepted Answer

Phosphate group

Question 4

A cell membrane is described as 'selectively permeable.' Which of the following molecules would most easily cross a pure phospholipid bilayer?

Accepted Answer

Oxygen ($$\mathrm{O_2$})$$

Question 5

Which of the following statements best explains why water is an efficient solvent for polar and ionic substances?

Accepted Answer

Water's polarity allows it to form hydrogen bonds and hydration shells around solutes.

Question 6

During the biosynthesis of a protein, which process is responsible for joining amino acids together?

Accepted Answer

Polymerization via condensation reactions

Question 7

Which property of water helps moderate Earth's climate by absorbing heat with only a slight change in its own temperature?

Accepted Answer

High specific heat

Question 8

A mutation causes a cell to lose the ability to form phospholipid bilayers. Which cellular function would be most directly affected?

Accepted Answer

Selective transport of molecules in and out of the cell

Question 9

Which of the following best describes the principle of self-assembly in biological systems?

Accepted Answer

The information for folding and assembly is inherent in the polymer's sequence.

Question 10

Which of the following is a correct sequence for the biosynthesis of a macromolecule from its basic building blocks?

Accepted Answer

Monomer → Macromolecule → Supramolecular assembly

Question 11

Which of the following best explains why ionic bonds are much weaker in aqueous solutions than covalent bonds?

Accepted Answer

Water forms hydration shells around ions, reducing the electrostatic attraction between them.

Question 12

Which functional group is found in all amino acids and is positively charged at physiological pH?

Accepted Answer

Amino group

Question 13

A scientist is studying a new polymer that forms spontaneously into a helical structure in water. Which principle does this observation best illustrate?

Accepted Answer

Strict self-assembly

Question 14

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

Accepted Answer

Low heat of vaporization

Question 15

Which of the following best describes the role of dehydration synthesis in macromolecule formation?

Accepted Answer

It joins monomers together by removing a molecule of water.

Question 16

Which of the following statements about carbon is FALSE?

Accepted Answer

Carbon has three valence electrons.

Question 17

Which of the following best explains why water expands as it freezes?

Accepted Answer

Hydrogen bonds form a crystalline lattice that spaces molecules farther apart.

Question 18

Which of the following is a real-life example of the importance of selectively permeable membranes?

Accepted Answer

The ability of red blood cells to maintain ion gradients across their plasma membrane

Question 19

Which of the following best describes the process of hydrolysis in macromolecule degradation?

Accepted Answer

Water is added to break a bond between monomers.

Question 20

Which of the following is a correct statement about the relationship between bond energy and stability in biological molecules?

Accepted Answer

Higher bond energy means the bond is more stable and less likely to break.

Chapter 2: The Chemistry of the Cell – Structured Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard