Question 1

Which of the following best describes the primary structure of a protein?

Accepted Answer

The sequence of amino acids in a polypeptide, stabilized by peptide bonds.

Question 2

A mutation causes a single amino acid change in the hemoglobin protein, resulting in sickle cell anemia. This illustrates the importance of which level of protein structure?

Accepted Answer

Primary structure

Question 3

Which type of bond is responsible for stabilizing the secondary structure of proteins?

Accepted Answer

Hydrogen bonds between groups along the peptide-bonded backbone

Question 4

Which of the following statements about phospholipids is correct?

Accepted Answer

Phospholipids are amphipathic, containing both hydrophilic heads and hydrophobic tails.

Question 5

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

Accepted Answer

Hydrogen bonds in ice create a lattice structure that is less dense than liquid water.

Question 6

A scientist adds cholesterol to a cell membrane. What effect will this have on the membrane's properties?

Accepted Answer

It will decrease the membrane's permeability by increasing the density of the hydrophobic section.

Question 7

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

Accepted Answer

They facilitate the movement of substances across the membrane via channels and carriers.

Question 8

Which process describes the movement of water across a selectively permeable membrane from a region of low solute concentration to high solute concentration?

Accepted Answer

Osmosis

Question 9

Which of the following statements about carbohydrates is true?

Accepted Answer

Monosaccharides can vary in the location of the carbonyl group, number of carbon atoms, and spatial arrangement of atoms.

Question 10

Which of the following best describes the role of molecular chaperones in cells?

Accepted Answer

They facilitate proper protein folding and block inappropriate interactions between unfolded proteins.

Question 11

Which of the following is a correct statement about the flow of genetic information in cells according to the central dogma?

Accepted Answer

DNA codes for RNA, which codes for protein.

Question 12

Which of the following is NOT a function of lipids in biological systems?

Accepted Answer

Serving as enzymes to catalyze chemical reactions.

Question 13

Which of the following best describes a dehydration (condensation) reaction?

Accepted Answer

A reaction in which a monomer is added to a polymer and water is released.

Question 14

Which of the following is true about the permeability of the phospholipid bilayer?

Accepted Answer

Small nonpolar molecules move across the membrane quickly.

Question 15

Which of the following is a correct statement about the pH scale?

Accepted Answer

A solution with pH less than 7 is acidic.

Question 16

Which of the following is a real-world example of active transport in cells?

Accepted Answer

Sodium-potassium pump moving sodium and potassium ions against their concentration gradients using ATP.

Question 17

Which equation correctly represents the formation of a peptide bond between two amino acids?

Accepted Answer

$$\mathrm{Amino\ acid}_1 + \mathrm{Amino\ acid}_2 \rightarrow \mathrm{Dipeptide} + H_2O$$

Question 18

Which of the following is a property of water that is critical for life on Earth?

Accepted Answer

Water expands as it freezes, making ice less dense than liquid water.

Question 19

Which of the following best explains why saturated fats are solid at room temperature?

Accepted Answer

Their hydrocarbon chains are straight and pack tightly together.

General Biology: Structure and Function of Biomolecules, Cell Theory, and Chemical Basis of Life

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