Daily Quiz 4

In a system at Gibbs-Donnan equilibrium, which statement correctly explains the movement of ions?

• Ions move to achieve equal concentration on both sides.

• Permeable ions distribute to balance the charge of impermeable ions.

• No net movement of ions occurs across the membrane.

• Ions move only due to active transport processes.

The Gibbs-Donnan equilibrium describes the distribution of ions in the presence of impermeable charged particles. What is a key consequence of this equilibrium in cells?

• Equal distribution of ions across the membrane.

• Increased intracellular concentration of permeable ions.

• Creation of an electrochemical gradient due to impermeable anions.

• Passive diffusion of impermeable ions.

The activity of the sodium-potassium pump is linked to various cellular processes. Which of the following processes relies on the gradient established by the sodium-potassium pump?

• Passive diffusion of glucose

• Secondary active transport of amino acids

• Simple diffusion of oxygen

• Passive transport of sodium ions

The sodium-potassium pump is essential for maintaining the resting membrane potential. How does it achieve this, and what is its significance in cell physiology?

• By exporting 2 K+ and importing 3 Na+, it maintains a negative charge inside the cell.

• By importing 3 Na+ and exporting 2 K+, it maintains an isotonic environment.

• By exporting 3 Na+ and importing 2 K+, it maintains a negative charge inside the cell.

• By exporting 2 Na+ and importing 3 K+, it maintains a positive charge inside the cell.

Which ion is predominantly found in the extracellular fluid and is essential for maintaining osmotic balance and fluid distribution?

• Potassium (K+)

• Sodium (Na+)

• Magnesium (Mg2+)

• Calcium (Ca2+)

Body fluid compartments are separated by membranes with specific permeability properties. Which statement correctly describes the distribution of body fluids?

• The intracellular fluid (ICF) contains the majority of the body’s water.

• The extracellular fluid (ECF) is mainly composed of interstitial fluid and intracellular fluid.

• Plasma constitutes the largest volume of extracellular fluid.

• The extracellular fluid has a higher concentration of potassium compared to the intracellular fluid.

Facilitated diffusion can reach saturation. What does this imply about its transport mechanism?

• It has an unlimited capacity for solute transport.

• It can become saturated when all carriers are occupied.

• It relies solely on the concentration gradient without limitation.

• It can transport any solute regardless of specific carrier availability.

Which of the following is true about facilitated diffusion and provides an accurate example?

• It is energy-dependent; an example is glucose uptake by GLUT-4.

• It moves molecules against their gradient; an example is calcium uptake in muscles.

• It requires carrier proteins; an example is glucose transport via GLUT-1.

• It does not involve proteins; an example is oxygen diffusion into cells.

Facilitated diffusion differs from simple diffusion in that it:

• Requires energy input to function.

• Moves molecules against their concentration gradient.

• Utilizes specific carrier proteins or channels.

• Involves the direct movement through the lipid bilayer.

Which process exemplifies passive transport, and what drives it?

• Facilitated diffusion of glucose driven by ATP.

• Osmosis of water driven by a solute concentration gradient.

• Active transport of ions driven by ion pumps.

• Endocytosis driven by cell energy expenditure.