Question

Which of the following statements is true? Inside the cell the quantity of positively charged ions is greater than the quantity of negatively charged ions. Inside the cell the quantity of positively charged ions is less than the quantity of negatively charged ions. Inside the cell the quantity of positively charged ions is almost exactly equal to the quantity of negatively charged ions?

1) Inside the cell the quantity of positively charged ions is greater than the quantity of negatively charged ions.
2) Inside the cell the quantity of positively charged ions is less than the quantity of negatively charged ions.
3) Inside the cell the quantity of positively charged ions is almost exactly equal to the quantity of negatively charged ions.

Answer 1

The quantity of positively charged ions is almost exactly equal to the quantity of negatively charged ions inside a cell, ensuring that the cell maintains a neutral charge. This balance is maintained by the sodium-potassium pump which actively transports ions across the cell membrane.

Step-by-step explanation:

The true statement about the charge balance inside a cell is that the quantity of positively charged ions is almost exactly equal to the quantity of negatively charged ions. Inside cells, a balance between cations (positively charged ions) and anions (negatively charged ions) is maintained to keep the cell neutral in charge. This is crucial for various cellular functions, including maintaining the resting membrane potential and propagating electrical signals.

The sodium-potassium pump plays a significant role in this balance. It uses ATP to pump two K+ ions into the cell while removing three Na+ ions per ATP consumed. Since more cations are expelled from the cell than taken in, the inside of the cell maintains a negative charge relative to the extracellular fluid. Large anions, such as phosphate ions and negatively charged proteins, contribute to this negative charge within the cell.

Despite the movement of ions, most body fluids remain neutral in charge due to the balance of cations and anions. The net charge on the inside and outside of the cell is zero, although specific ion concentrations may differ significantly. The sodium-potassium pumps ensure that high levels of potassium remain inside the cell while sodium is pumped out, helping to maintain this charge neutrality.

Answer 2

Among the given options, the true statement is 2) "Inside the cell, the quantity of positively charged ions is less than the quantity of negatively charged ions."

Step-by-step explanation:

The question at hand is addressing the balance of ions inside a cell and it's related to the concept of membrane potential and ion concentration gradients in biological systems. Specifically, we are looking to determine the relative quantities of positively and negatively charged ions within a cell.

It is important to note that most body fluids are neutral in charge, indicating that the number of positively charged ions, or cations, is balanced by the number of negatively charged ions, or anions. Mechanisms like the sodium-potassium pump actively maintain this balance by expelling more sodium ions (Na+) from the cell than potassium ions (K+) taken into the cell, consuming ATP in the process.

Considering these points, the quantity of positively charged ions inside the cell is less than the quantity of negatively charged ions. This creates a negatively charged environment relative to the outside of the cell, contributing to the resting membrane potential. The specific question asked falls under the context of cellular ion balance and its relevance to the overall charge neutrality of cells in relation to their environment.

Hence, the correct answer is Option 2.