Question 1

Which property of water is primarily responsible for its ability to act as an efficient solvent for ionic and polar substances?

Accepted Answer

Its bent molecular geometry and overall polarity

Question 2

A scientist adds a nonpolar molecule to water and observes that it does not dissolve. What is the main reason for this observation?

Accepted Answer

Nonpolar molecules are hydrophobic and do not interact favorably with water's partial charges

Question 3

Which of the following best explains why ice floats on liquid water?

Accepted Answer

Hydrogen bonds in ice create an open crystal structure, making it less dense than liquid water

Question 4

A solution has a pH of 5. What is the concentration of hydrogen ions $$[H^+] in $$this solution?

Accepted Answer

$$1 	imes 10$$^{-5}$$ M

Question 5

Which functional group is most likely to act as a base by accepting a proton in aqueous solution?

Accepted Answer

Amino group

Question 6

Which of the following statements about protein structure is correct?

Accepted Answer

Secondary structure is formed by hydrogen bonds between the carbonyl group of one amino acid and the amino group of another

Question 7

A mutation changes a single amino acid in the primary structure of hemoglobin, resulting in sickle cell disease. What does this illustrate about protein structure?

Accepted Answer

A change in primary structure can radically alter protein function

Question 8

Which type of interaction is responsible for stabilizing the tertiary structure of a protein by forming disulfide bonds?

Accepted Answer

Covalent bonding between sulfhydryl groups

Question 9

What is the main function of molecular chaperones in cells?

Accepted Answer

They facilitate proper folding of proteins

Question 10

Which of the following best describes the peptide bond formed during protein synthesis?

Accepted Answer

A covalent bond between the carboxyl group of one amino acid and the amino group of another

Question 11

A protein is exposed to high heat and loses its three-dimensional structure. What is the most likely consequence?

Accepted Answer

The protein will become denatured and lose its function

Question 12

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

Accepted Answer

Storing genetic information

Question 13

Which property of water allows it to move upward against gravity in the xylem of plants?

Accepted Answer

Cohesion and adhesion due to hydrogen bonding

Question 14

Which of the following best explains why sweating cools the body?

Accepted Answer

Water has a high heat of vaporization, so it absorbs a large amount of energy when it evaporates

Question 15

Which of the following amino acid side chains is most likely to be found on the surface of a protein in an aqueous environment?

Accepted Answer

A charged or polar side chain

Question 16

A buffer solution contains a weak acid $$HA$$ and its conjugate base $$A^-. If a $$small amount of strong acid is added, what will happen to the pH?

Accepted Answer

The pH will remain relatively constant

Question 17

Which of the following statements about carbon is true and explains its central role in organic molecules?

Accepted Answer

Carbon forms four covalent bonds, allowing for a limitless array of molecular shapes

Question 18

Which level of protein structure is directly responsible for the formation of a functional enzyme's active site?

Accepted Answer

Tertiary structure

Question 19

Which of the following best describes the effect of prion proteins on normal proteins?

Accepted Answer

Prion proteins induce normal proteins to change their shape to the infectious form

Question 20

Which process increases entropy and is energetically favorable in the breakdown of biological polymers?

Accepted Answer

Hydrolysis

Water, Carbon, and Protein Structure: The Chemical Basis of Life

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