Question 1

Which property of carbon most directly enables it to form large, complex, and diverse molecules essential for life?

Accepted Answer

Its four valence electrons allowing it to form four covalent bonds

Question 2

Which of the following is NOT considered a macromolecule in living organisms?

Accepted Answer

Nucleic acids

Question 3

A dehydration reaction is crucial in the synthesis of polymers. What is the net chemical change during a dehydration reaction?

Accepted Answer

A water molecule is removed to form a covalent bond between monomers

Question 4

Which functional group is found in all amino acids and is responsible for their acidic properties?

Accepted Answer

Carboxyl group ($$-COOH)$$

Question 5

Cellulose and starch are both polymers of glucose. What structural difference accounts for their distinct properties?

Accepted Answer

Cellulose has $$\beta-1$$,4 glycosidic linkages, while starch has $$\alpha-1$$,4 glycosidic linkages

Question 6

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

Accepted Answer

Saturated fatty acids have the maximum number of hydrogen atoms

Question 7

A patient is diagnosed with sickle-cell disease. Which molecular change is responsible for this condition?

Accepted Answer

A single amino acid substitution in the primary structure of hemoglobin

Question 8

Which of the following best describes the structure of a phospholipid in a cell membrane?

Accepted Answer

A hydrophilic head and two hydrophobic tails

Question 9

Which type of chemical bond joins nucleotides together in a polynucleotide chain?

Accepted Answer

Phosphodiester bond

Question 10

A scientist is studying the evolutionary relationship between two species using molecular biology. Which molecule would provide the most direct evidence for evolutionary kinship?

Accepted Answer

The sequence of nucleotides in DNA

Question 11

Which of the following is a correct description of complementary base pairing in DNA?

Accepted Answer

Adenine pairs with thymine, guanine pairs with cytosine

Question 12

Which process is responsible for breaking down polymers into monomers in the digestive tract?

Accepted Answer

Hydrolysis

Question 13

Which of the following best explains why lipids are hydrophobic?

Accepted Answer

They are composed mostly of hydrocarbons, which form nonpolar covalent bonds

Question 14

Which of the following is a function of ATP in the cell?

Accepted Answer

It acts as the primary energy-transferring molecule

Question 15

Which level of protein structure is directly determined by the sequence of amino acids?

Accepted Answer

Primary structure

Question 16

A protein loses its three-dimensional structure and becomes biologically inactive after exposure to high temperature. What is this process called?

Accepted Answer

Denaturation

Question 17

Which of the following is true about the antiparallel arrangement of DNA strands?

Accepted Answer

The two strands run in opposite 5' to 3' directions

Question 18

Which of the following is a structural polysaccharide found in the exoskeleton of arthropods and the cell walls of fungi?

Accepted Answer

Chitin

Question 19

Which of the following best describes the difference between DNA and RNA?

Accepted Answer

DNA contains deoxyribose sugar, while RNA contains ribose sugar

Question 20

Which of the following is a correct sequence of events in the flow of genetic information in a cell?

Accepted Answer

DNA → RNA → protein

Carbon and the Molecular Diversity of Life: Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard