Q: Which equation best represents the selective permeability of the cell membrane, considering the movement of ions across the membrane?

The Nernst equation: $$E = \frac{RT}{zF} \ln \frac{[\text{ion outside}]}{[\text{ion inside}]}$$

Question 1

Which of the following statements best distinguishes prokaryotic cells from eukaryotic cells?

Accepted Answer

Prokaryotic cells lack a nucleus and membrane-bound organelles, while eukaryotic cells possess both.

Question 2

A bacterium is observed to have a thick peptidoglycan layer and stains purple after a Gram stain. Which of the following is most likely true about this bacterium?

Accepted Answer

It is Gram-positive and contains teichoic acids in its cell wall.

Question 3

Which structure allows bacteria to transfer genetic material directly from one cell to another, and what is this process called?

Accepted Answer

Pili; conjugation

Question 4

A patient is infected with a Gram-negative bacterium. Which component of the bacterial cell wall is most likely responsible for symptoms such as fever and shock?

Accepted Answer

Lipid A portion of lipopolysaccharide (LPS)

Question 5

Which of the following best describes the function of the bacterial glycocalyx capsule?

Accepted Answer

It prevents bacteria from being recognized by the host immune system.

Question 6

Which equation best represents the selective permeability of the cell membrane, considering the movement of ions across the membrane?

Accepted Answer

The Nernst equation: $$E = \frac{RT}{zF} \ln \frac{[	ext{ion outside}]}{[	ext{ion inside}]}$$

Question 7

Which of the following is a defensive structure produced by some bacteria that allows them to survive extreme conditions such as heat and radiation?

Accepted Answer

Endospore

Question 8

A scientist is studying a microorganism with a cell wall composed of specialized polysaccharides and proteins, but no peptidoglycan. Which type of organism is she most likely studying?

Accepted Answer

Archaeon

Question 9

Which of the following statements about ribosomes is correct?

Accepted Answer

Prokaryotic cells have 70s ribosomes, while eukaryotic cells have 80s ribosomes.

Question 10

Which of the following best explains why antibiotics targeting peptidoglycan are effective against bacteria but not against archaea?

Accepted Answer

Archaea do not have peptidoglycan in their cell walls, so antibiotics targeting peptidoglycan do not affect them.

Question 11

Which of the following structures is most important for the formation of biofilms in both bacteria and archaea?

Accepted Answer

Glycocalyces

Question 12

A bacterium moves toward a chemical attractant by alternating between 'runs' and 'tumbles.' Which structure is responsible for this movement, and what is the mechanism?

Accepted Answer

Flagella; rotation of the filament

Question 13

Which of the following is a function of the bacterial cytoskeleton?

Accepted Answer

Maintaining cell shape and assisting in cell division

Question 14

Which process involves the chemical modification of a substance as it is transported across the bacterial cell membrane?

Accepted Answer

Group translocation

Question 15

A researcher observes a microorganism with circular DNA, 70s ribosomes, and a fibrous cytoskeleton. However, its ribosomal proteins and genetic code are more similar to eukaryotes. What is the most likely identity of this organism?

Accepted Answer

Archaeon

Question 16

Which of the following best describes the fluid mosaic model of the cell membrane?

Accepted Answer

A dynamic structure with proteins and lipids moving laterally within a phospholipid bilayer.

Question 17

Which of the following equations best describes the osmotic pressure exerted by solutes across a bacterial cell wall?

Accepted Answer

Osmotic pressure equation: $$\Pi = iMRT$$

Question 18

Which of the following is NOT a function of bacterial cell walls?

Accepted Answer

Synthesizing proteins for the cell

Question 19

Which of the following is true regarding the external structures of archaea?

Accepted Answer

Archaea have flagella with a basal body, hook, and filament, but these differ from bacterial flagella.

Question 20

A bacterium is found to lack a cell wall but still possesses ribosomes. Which of the following is most likely true?

Accepted Answer

It is a prokaryote with other typical prokaryotic features.

Cell Structure and Function in Prokaryotes and Archaea

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