Question 1

Which of the following elements is NOT considered one of the four most abundant elements in living systems?

Accepted Answer

Sulfur (S)

Question 2

Which class of biological macromolecule is NOT formed by polymerization of identical or similar monomeric units?

Accepted Answer

Lipids

Question 3

What type of bond links the monomers in nucleic acids?

Accepted Answer

Phosphodiester bond

Question 4

Which property of water is MOST responsible for its ability to dissolve ionic compounds?

Accepted Answer

Relatively high dielectric constant

Question 5

A solution has a hydrogen ion concentration of $$1 	imes 10$$^{-6}$$ M. What is its pH?

Accepted Answer

$$pH = 6$$

Question 6

Which of the following is a correct statement about amphipathic molecules in water?

Accepted Answer

They can form micelles, monolayers, or bilayers depending on concentration and structure.

Question 7

Which of the following ions is NOT typically essential for life?

Accepted Answer

Pb$$^{2+}$$

Question 8

Which linkage is found between monosaccharide units in polysaccharides?

Accepted Answer

Glycosidic (ether) bond

Question 9

Which of the following best describes the role of lipids in biological membranes?

Accepted Answer

They form the structural basis of the membrane, creating compartments within cells.

Question 10

Which statement about acids and bases according to the Brønsted-Lowry definition is correct?

Accepted Answer

Acids are proton donors and bases are proton acceptors.

Question 11

Which of the following is a consequence of water’s molecular lattice structure in the solid state?

Accepted Answer

Ice is less dense than liquid water.

Question 12

A protein’s overall surface charge changes as the pH of its environment changes. This is primarily due to:

Accepted Answer

Ionization of amino acid side chains.

Question 13

Which of the following is a correct physiological pH range for most biological reactions?

Accepted Answer

$$6.5 \leq pH \leq 8.0$$

Question 14

Which of the following is a monomeric unit of proteins?

Accepted Answer

Amino acid

Question 15

Which of the following is a function of cholesterol in biological membranes?

Accepted Answer

It modulates membrane fluidity.

Question 16

Which of the following best explains why water has a high heat capacity?

Accepted Answer

Extensive hydrogen bonding between water molecules.

Question 17

Which of the following is the correct formula for calculating pH from hydrogen ion concentration?

Accepted Answer

$$pH = -\log [H^+]$$

Question 18

Which of the following is a real-world example of an amphipathic molecule forming a bilayer?

Accepted Answer

Phospholipids in cell membranes

Question 19

Which of the following is a correct statement about the relationship between pH and molecular charge?

Accepted Answer

As pH changes, the ionization state of biomolecules changes, altering their surface charge.

Question 20

Which of the following is a correct description of the role of sodium ions (Na$$^+) in $$biological systems?

Accepted Answer

They help maintain osmotic balance and are essential for nerve impulse transmission.

Foundations of Biochemistry: Chemical Elements, Macromolecules, Water, and pH

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