Biology Assignment: Sodium-Potassium Pump, Transport, and Diffusion

This assignment delves into the sodium-potassium pump, a critical component of cellular transport. It explains the process of active transport, facilitated by the Na+/K+ ATPase, which requires ATP to move sodium and potassium ions against their concentration gradients. The assignment references the kidneys and the renin-angiotensin-aldosterone system, highlighting how this pump is essential for maintaining electrolyte balance. It also touches upon neurotransmitter movement, involving vesicular membrane fusion and exocytosis. The assignment differentiates between diffusion and osmosis, emphasizing that only facilitated diffusion requires energy. Furthermore, the assignment includes references to relevant research papers, supporting the understanding of the sodium-potassium pump and its biological implications.

Movement of Sodium-Potassium pump:
The sodium-potassium pump by means of active transport will move through plasma
membrane with the help of carrier molecule referred to as Na+,K+ ATPase. This process
requires ATP as energy source to function and 3 sodium ions in one direction followed by 2
potassium ions move in opposite direction and this can be explained by following example.
In Kidneys, Sodium ion is conserved normally for exchange of K+ ion and this is excreted
into proximal convoluted tubule. This process is facilitated by Renin-Aldosterone-
Angiotensin system which is associated with Addison’s disease that occurs due to deficiency
of aldosterone production from adrenal cortex resulting in causing hypovolaemia condition
which means sodium loss is reported.
Alternatively, neurotransmitters movement across plasma membrane will involve the
vesicular membrane fusion in which vesicles are either round or oval and globules are
composed of neurotransmitter present along the plasma membrane and this entire procedure
is referred to exocytosis (Bonanno, 2012).
Diffusion:
Diffusion is passive amount of molecules from high concentration region to lower
concentration region . Only Facilitated type of diffusion process requires ATP as energy
source.
Osmosis:
Osmosis is a process of water diffusion through semipermeable membrane from dilute
solution to concentrated solution without energy source.
Active transport:
Active transport involves substance transfer through cell membrane which is against the
gradient of concentration i.e. from lower to higher concentration without energy source.
Na +/ K+
Sodium-Potassium pump is present in plasma membrane in which the sodium and potassium
ions will travel in opposite direction using ATP and are against the concentration gradient
(Lu & Hilgemann, 2017).

References
Bonanno JA., 2012. Molecular mechanisms underlying the corneal endothelial
pump. Experimental eye research, 95(1), 2–7. doi:10.1016/j.exer.2011.06.004
Lu, FM., & Hilgemann, DW, 2017. Na/K pump inactivation, subsarcolemmal Na
measurements, and cytoplasmic ion turnover kinetics contradict restricted Na spaces in
murine cardiac myocytes. The Journal of general physiology, 149(7), 727–749.
doi:10.1085/jgp.201711780