Question

Discuss TWO essential biological functions that prokaryotic organisms and eukaryotic organisms are able to perform using each type of transport. Are there ways in which the cell membrane of a prokaryotic organism or cell functions differently from a eukaryotic organism using either of these methods of transport? You may need to look around into passive and active transport uses in prokaryotic and eukaryotic cell membranes for this response.

Answer 1

Answer: Transport Across the cell membrane depends upon number of proteins termed as Uniporters, Symporters and Antiporters.

Uniporters can be considered similar to water filled channels in Gram Negative bacteria. In which the uniporter is a single or collection of different proteins that allow the movement of molecules across the membrane. The movement may be selective based on molecule size and hence small channels may prevent the entry of large molecules. Movement of molecules in or out without any energy input is termed as passive transport.

An antiporter is a membrane protein that can transport two molecules at same time across the membrane in which it is embedded. One molecules may be transported in one direction while the other may simultaneously transported in opposite direction. This type of transport require energy and hence it is an active transport.

The third type of transport protein is termed a symport. This type of protein can simultaneously transport two molecules across a membrane in the same direction. This type of transport requires energy and hence it is an active transport.

Removal of unwanted metabolic waste out of the cell in bacteria is a type of passive transport.

Active Transport Examples- Endocytosis, Exocytosis, Phagocytosis, pinocytosis, Sodium Potasium Pump.

Passive Transport Examples- Osmosis, diffusion and facilitated diffusion.