Question 1

Which of the following best describes the relationship between atomic structure and the chemical properties of an element?

Accepted Answer

The arrangement of electrons in the outermost shell determines the element's chemical reactivity.

Question 2

A researcher is studying a protein that loses its function when exposed to high temperatures. Which level of protein structure is most directly affected by this denaturation?

Accepted Answer

Tertiary structure

Question 3

Which of the following best explains why water is an excellent solvent for ionic compounds?

Accepted Answer

Water molecules are polar and can surround and separate ions due to their partial charges.

Question 4

A patient is diagnosed with a disorder that affects the sodium-potassium pump in nerve cells. Which of the following best describes the immediate consequence of this malfunction?

Accepted Answer

The cell will lose its ability to maintain an electrochemical gradient across the membrane.

Question 5

Which of the following is a correct comparison between saturated and unsaturated fatty acids?

Accepted Answer

Saturated fatty acids have no double bonds between carbon atoms, making them more likely to be solid at room temperature.

Question 6

Which of the following equations correctly represents the hydrolysis of a disaccharide such as sucrose?

Accepted Answer

$$ \mathrm{C_{12}H_{22}O_{11}} + \mathrm{H_2O} \rightarrow \mathrm{C_6H_{12}O_6} + \mathrm{C_6H_{12}O_6} $$

Question 7

Which of the following best distinguishes between covalent and ionic bonds?

Accepted Answer

Covalent bonds involve the sharing of electrons, while ionic bonds involve the transfer of electrons.

Question 8

A scientist is comparing the storage polysaccharides in plants and animals. Which of the following statements is correct?

Accepted Answer

Plants store energy as starch, while animals store energy as glycogen.

Question 9

Which of the following best explains why phospholipids form bilayers in aqueous environments?

Accepted Answer

Phospholipids have both hydrophilic heads and hydrophobic tails, causing them to arrange with heads facing water and tails facing inward.

Question 10

Which of the following is an example of active transport across a cell membrane?

Accepted Answer

Glucose moving into a cell via a sodium-glucose symporter using ATP.

Question 11

A mutation causes a protein to lose its quaternary structure but retain its tertiary structure. Which of the following is most likely to occur?

Accepted Answer

The protein will function as a monomer but lose any cooperative or regulatory functions provided by subunit interactions.

Question 12

Which of the following best describes the difference between simple diffusion and facilitated diffusion?

Accepted Answer

Facilitated diffusion requires a membrane protein, while simple diffusion does not.

Question 13

Which of the following is a correct description of a peptide bond?

Accepted Answer

A bond formed between the carboxyl group of one amino acid and the amino group of another, releasing water.

Question 14

Which of the following best explains why cellulose is not digestible by humans, while starch is?

Accepted Answer

Humans lack the enzyme to break the $$\beta-1$$,4 glycosidic bonds in cellulose, but can break the $$\alpha-1$$,4 bonds in starch.

Question 15

Which of the following best describes the role of cholesterol in animal cell membranes?

Accepted Answer

Cholesterol increases membrane fluidity at low temperatures and decreases it at high temperatures.

Question 16

A solution contains 0.1 M NaCl and 0.1 M glucose. Which of the following statements is correct regarding the osmotic pressure of this solution?

Accepted Answer

The osmotic pressure is equal to a 0.2 M glucose solution because NaCl dissociates into two particles.

Question 17

Which of the following is a correct statement about the four levels of protein structure?

Accepted Answer

Tertiary structure is stabilized by interactions between R groups of amino acids.

Question 18

Which of the following best describes the function of a sodium-potassium pump?

Accepted Answer

It uses ATP to move sodium ions out of the cell and potassium ions into the cell, creating an electrochemical gradient.

Question 19

Which of the following best explains why phospholipids are amphipathic molecules?

Accepted Answer

They have both a hydrophilic phosphate head and hydrophobic fatty acid tails.

Question 20

A cell is placed in a hypertonic solution. What will most likely happen to the cell?

Accepted Answer

The cell will lose water and shrink.

General Biology: Structure and Function of Biomolecules Study Notes

Guida di studio - Domande di pratica

Study guide - Flashcard