Question

Which method of transport in the plasma membrane does not require carrier molecules
A. Simple diffusion
B. Facilitated diffusion
C. Active transport
D. Na+ - K+ pump mechanism

Answer 1

Hint: In passive transport, there is no energy wasted. Passive transport happens through diffusion and osmosis. Simple diffusion is said to an activity of particles from the area of their high engagement to the area of their lower engagement. Electrochemical potential regulates in the case of indicted particles such as ions.

Complete step by step answer: There are various method of transport in the plasma membrane let us consider all methods of transport one by one-
A. Simple diffusion is the procedure by which solutes are shifted along with an engagement gradient in a solution or across a semipermeable membrane. The Simple diffusion process is reached by the actions of hydrogen bonds shaping between water molecules and solutes.
B. Facilitated diffusion is also known as facilitated transport as well as passive-mediated transport. It is the process of spontaneous passive transport that is as opposed to active transport. This of molecules or ions across a biological membrane via specific transmembrane integral proteins. Being a passive, facilitated transport does not directly compel chemical energy from ATP hydrolysis in the transport stride itself; rather, molecules along with ions move down their concentration gradient indicating its diffusive nature.
C. In cellular biology,  the term active transport is said to the trend of molecules across a cell membrane from an area of lower concentration to an area of higher concentration. This is against the concentration gradient. Active transport also needs cellular energy to achieve this action.
D. The Na+ K+ pump is an electro-genic transmembrane. It is the ATPase first discovered in the year 1957 as well as situated in the outer plasma membrane of the cells; on the cytosolic side. The Na+ K+ ATPase pumps 3Na+ out of the cell along with 2K+ which into the cell, for every single ATP depleted.
So, the right answer is option A “Simple Diffusion”

Note: Facilitated diffusion occurs with the support of special facilitator proteins or permeates. Active transport needs special carriers as well as gated channels. The sodium-potassium exchange pump operates across many animal membranes.