Question 1

Which property of carbon makes it uniquely suited to form the backbone of biological macromolecules?

Accepted Answer

Its valence of 4, allowing it to form stable covalent bonds with up to four other atoms.

Question 2

Which of the following best explains why water is an excellent solvent for biological molecules?

Accepted Answer

Water is a polar molecule, allowing it to surround and interact with ions and other polar molecules.

Question 3

A new anti-cancer drug is large and contains many polar functional groups, making it unable to cross the cell membrane. Which strategy would most likely increase its cellular uptake?

Accepted Answer

Attach the drug to a carrier molecule that is recognized by a membrane transporter.

Question 4

Which of the following statements about the lipid bilayer of cell membranes is correct?

Accepted Answer

The bilayer is amphipathic, with hydrophilic heads facing outward and hydrophobic tails facing inward.

Question 5

Which of the following best describes a condensation reaction in the synthesis of macromolecules?

Accepted Answer

A reaction in which two monomers are joined together with the removal of a water molecule.

Question 6

Which of the following functional groups is neutral but polar?

Accepted Answer

Hydroxyl

Question 7

A protein is denatured by heat and then allowed to cool slowly. What is the most likely outcome?

Accepted Answer

The protein will spontaneously refold into its native, functional conformation.

Question 8

Which of the following molecules would be most permeable through a pure phospholipid bilayer?

Accepted Answer

O$$_2$$

Question 9

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

Accepted Answer

Hydrogen bonds

Question 10

How many possible stereoisomers exist for a molecule with 3 asymmetric carbons?

Accepted Answer

$$2^3 = 8$

Question 11

Which of the following best explains why double and triple bonds are more stable than single bonds?

Accepted Answer

They involve more shared electron pairs, resulting in higher bond energies.

Question 12

Which of the following is a correct statement about hydrogen bonds in water?

Accepted Answer

They are responsible for water's high heat of vaporization.

Question 13

Which of the following best describes an amphipathic molecule?

Accepted Answer

A molecule with both hydrophilic and hydrophobic regions.

Question 14

Which of the following is a real-world example of the importance of water's surface tension?

Accepted Answer

The ability of insects to walk on water.

Question 15

Which of the following statements about the permeability of the plasma membrane is correct?

Accepted Answer

Small nonpolar molecules can diffuse freely across the membrane.

Question 16

Which of the following interactions is the weakest?

Accepted Answer

Van der Waals interaction

Question 17

Which process is responsible for breaking down polymers into monomers in biological systems?

Accepted Answer

Hydrolysis

Question 18

Which of the following is a function of chaperone proteins in cells?

Accepted Answer

They assist in the proper folding of other proteins.

Question 19

Which of the following best explains why hydrocarbons are insoluble in water?

Accepted Answer

They are nonpolar and cannot form hydrogen bonds with water.

Question 20

Which of the following is a correct statement about the directionality of macromolecule synthesis?

Accepted Answer

Macromolecules are synthesized in a specific direction, such as 5' to 3' for nucleic acids.

The Chemistry of the Cell: Structure, Bonds, Water, and Macromolecules

Guida di studio - Domande di pratica

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