$$[H^+] = 1 \times 10$$^{-6}$$ M

Question 1

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

Accepted Answer

Phosphorus (P)

Question 2

Which class of biological macromolecules is NOT formed by polymerization of identical or similar monomeric subunits?

Accepted Answer

Lipids

Question 3

What type of chemical bond links the monomers in nucleic acids?

Accepted Answer

Phosphodiester bond

Question 4

Which of the following ions is essential for nerve impulse transmission and muscle contraction in humans?

Accepted Answer

K$$^+$$

Question 5

A protein is composed of a chain of amino acids linked by which type of bond?

Accepted Answer

Peptide (amide) bond

Question 6

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

Accepted Answer

Relatively high dielectric constant

Question 7

Which of the following best describes an amphipathic molecule?

Accepted Answer

A molecule with both hydrophilic and hydrophobic regions

Question 8

Which of the following is the correct formula for calculating pH?

Accepted Answer

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

Question 9

If the concentration of hydrogen ions in a solution is $$1 	imes 10$$^{-4}$$ M, what is the pH of the solution?

Accepted Answer

$$pH = 4$$

Question 10

Which of the following statements about acids and bases is TRUE according to the Brønsted-Lowry definition?

Accepted Answer

Acids are proton donors and bases are proton acceptors

Question 11

Which of the following best explains why the physiological pH range is important for biomolecular interactions?

Accepted Answer

It affects the overall surface charge of biomolecules

Question 12

Which macromolecule is primarily responsible for storing genetic information?

Accepted Answer

Nucleic acids

Question 13

Which of the following is a correct pairing of macromolecule and its monomer?

Accepted Answer

Polysaccharide – Monosaccharide

Question 14

Which of the following is a function of lipids in biological systems?

Accepted Answer

Forming cellular membranes

Question 15

A solution has a pH of 6. What is the hydrogen ion concentration $$[H^+] in $$this solution?

Accepted Answer

$$[H^+] = 1 	imes 10$$^{-6}$$ M

Question 16

Which of the following best describes the structure of a phospholipid bilayer?

Accepted Answer

A double layer of lipids with hydrophilic heads facing outward and hydrophobic tails facing inward

Question 17

Which property of water allows it to form hydrogen bonds with other molecules?

Accepted Answer

Its permanent dipole

Question 18

Which of the following is a correct statement about the effect of pH on proteins?

Accepted Answer

Changes in pH can alter the overall surface charge of proteins

Question 19

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

Accepted Answer

Formation of a phospholipid bilayer in cell membranes

Question 20

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

Accepted Answer

Ice has a lower density than liquid water due to its molecular lattice structure

Foundations of Biochemistry: Chemical Elements, Macromolecules, and Water

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