Question 1

Which property of carbon most directly explains its ability to form large, complex, and diverse molecules essential for life?

Accepted Answer

Its four valence electrons allow it to form up to four covalent bonds with a variety of atoms.

Question 2

Which of the following best describes a structural isomer?

Accepted Answer

Molecules with the same molecular formula but different covalent arrangements of their atoms.

Question 3

A dehydration reaction is essential in the formation of which type of biological molecule?

Accepted Answer

Polymers from monomers

Question 4

Which functional group is most likely to act as an acid by donating a hydrogen ion ($H^+$) in aqueous solution?

Accepted Answer

Carboxyl group ($-COOH$)

Question 5

Which of the following statements about saturated and unsaturated fats is correct?

Accepted Answer

Saturated fats are typically found in animal products and are solid at room temperature.

Question 6

A patient is diagnosed with sickle-cell disease, which is caused by a single amino acid substitution in the hemoglobin protein. This is an example of how a change in which level of protein structure can affect function?

Accepted Answer

Primary structure

Question 7

Which of the following best explains why cellulose is difficult for most animals to digest?

Accepted Answer

Cellulose contains $\beta$-glycosidic linkages, and most animals lack enzymes to hydrolyze these bonds.

Question 8

Which of the following is a correct pairing of a nitrogenous base with its complementary base in DNA?

Accepted Answer

Adenine ($A$) pairs with thymine ($T$)

Question 9

A phospholipid differs from a fat (triglyceride) in which of the following ways?

Accepted Answer

A phospholipid has a phosphate group and two fatty acids attached to glycerol, while a fat has three fatty acids.

Question 10

Which of the following best describes the backbone of a polynucleotide strand in DNA?

Accepted Answer

A chain of alternating phosphate and pentose sugar groups

Question 11

Which of the following statements about protein denaturation is correct?

Accepted Answer

Denaturation disrupts the secondary, tertiary, or quaternary structure of a protein, often rendering it biologically inactive.

Question 12

Which of the following best explains why fats are a more efficient energy storage molecule than carbohydrates?

Accepted Answer

Fats store more than twice as much energy per gram as carbohydrates due to their reduced, hydrocarbon-rich structure.

Question 13

Which of the following is NOT a function of proteins in living organisms?

Accepted Answer

Storing genetic information

Question 14

Which of the following statements about the directionality of DNA strands is correct?

Accepted Answer

The two strands of DNA run in opposite directions, described as antiparallel.

Question 15

Which of the following best describes the process of hydrolysis in biological systems?

Accepted Answer

Hydrolysis breaks down polymers into monomers by adding a water molecule.

Question 16

Which of the following is a correct statement about enantiomers?

Accepted Answer

Enantiomers are mirror images of each other and cannot be superimposed.

Question 17

Which of the following best explains the amphipathic nature of phospholipids and their role in biological membranes?

Accepted Answer

Phospholipids have both hydrophilic heads and hydrophobic tails, allowing them to form bilayers that separate aqueous environments.

Question 18

Which of the following best describes the relationship between genomics and proteomics?

Accepted Answer

Genomics is the study of entire sets of genes, while proteomics is the study of entire sets of proteins expressed by a cell or organism.

Question 19

A scientist is comparing the DNA sequences of two species to determine their evolutionary relationship. Which property of DNA makes this possible?

Accepted Answer

The linear sequence of nucleotides in DNA is inherited and can be compared across species.

Chapter 3: Carbon and the Molecular Diversity of Life – Study Notes

Study Guide - Practice Questions

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