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 is an example of how:

Accepted Answer

Changes in primary structure can affect the function of the entire protein.

Question 3

Which type of bond is primarily 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 TRUE?

Accepted Answer

Phospholipids are amphipathic, containing both hydrophilic and hydrophobic regions.

Question 5

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

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 cells?

Accepted Answer

All of the above.

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 CORRECT?

Accepted Answer

Carbohydrates are important for energy storage and cell structure.

Question 10

Which of the following is the correct formula for a carbohydrate with n carbon atoms?

Accepted Answer

$$\mathrm{C}_n\mathrm{H}_{2n}\mathrm{O}_n$$

Question 11

Which of the following best describes the difference between saturated and unsaturated fatty acids?

Accepted Answer

Saturated fatty acids contain only single bonds between carbon atoms, while unsaturated fatty acids contain one or more double bonds.

Question 12

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

Accepted Answer

Catalyzing chemical reactions

Question 13

Which of the following statements about the fluid mosaic model of cell membranes is TRUE?

Accepted Answer

Phospholipids and proteins can move laterally within the membrane.

Question 14

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

Accepted Answer

Cohesion and adhesion due to hydrogen bonding

Question 15

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

Accepted Answer

A reaction in which two monomers are joined together and a molecule of water is released.

Question 16

Which of the following is TRUE regarding the movement of molecules across a phospholipid bilayer?

Accepted Answer

Small nonpolar molecules move across the bilayer quickly.

Question 17

Which of the following is a correct statement about facilitated diffusion?

Accepted Answer

It involves proteins that help substances move down their concentration gradient.

Question 18

Which of the following is a property of enzymes that allows them to speed up chemical reactions?

Accepted Answer

Enzymes provide a specific chemical environment that stabilizes the transition state.

Question 19

Which of the following is TRUE about the pH scale?

Accepted Answer

A solution with pH 7 is neutral.

General Biology Study Notes: Biomolecules, Cell Theory, and Chemical Foundations

Guida di studio - Domande di pratica

Study guide - Flashcard