Question

How does potassium ions enter a cell?

Answer 1

Hint: Potassium is a type of mineral and electrolyte in the body. It assists in the conduction of nerve signals, contraction and movement of muscles, functioning of the heart in the form of electrolyte. Potassium ions in its mineral form helping the development and functioning of cells, tissues and organs.

Complete answer:
Potassium ions are the most abundant positive ions present inside the cell wall. These ions are also present in the blood.
Potassium ions can be transferred in and out of the cell through active and passive transport.
Passive movement: Three passive forces namely chemical, electrical and electrochemical gradient are responsible for the movement of potassium ions inside and outside of the cell. Potassium ions are present in higher concentration inside the cell which leads to the development of chemical gradient which pushes potassium ions outside the cell but as soon as they move out negatively charge proteins attract the positively charged potassium ions again inside the cell leading to the development of electrochemical gradient. Potassium ions continuously move inside and outside of the cell until equilibrium is achieved.
Active movement: This type of movement is through the sodium-potassium pump which is scattered in the cell membrane. There is a constant leakage of sodium ions inside the cell. Sodium potassium pump functions in maintaining electrical charges in and out of the cell. To achieve this pump removes three negatively charged sodium ions out of the cell and allows the entry of two positively charged potassium ions inside the cell.

Note:
Movement of potassium ions in and out of the cell is through the potassium channels present in the cell wall. Opening and closing of these channels depend on potential difference inside and outside of the cell. Negatively charged chloride ions and positively charged sodium are present outside the cell and positively charged potassium and negatively charged proteins are present inside the cell that accounts for the potential difference. Sodium potassium pump helps in active transfer of potassium ions.