Question

"The model above shows a cell moving a substance into the cell using a protein to facilitate the transport. Which substance is most

likely being transported through the membrane with this method?
A) Glucose
B) Oxygen gas
C) Nitrogen gas
D) Carbon dioxide gas"

Answer 1

The cell uses facilitated diffusion with the help of transport proteins to move certain substances across its membrane. Oxygen and carbon dioxide can move through simple diffusion without assistance, so the substance requiring facilitated transport is likely neither of these gases.

Step-by-step explanation:

The cell model indicated the movement of substances across the cell membrane with the help of transport proteins. This process is known as facilitated diffusion. In biology, it's understood that small, nonpolar molecules like oxygen (O2) and carbon dioxide (CO2) can move through the lipid bilayer via simple diffusion, a form of passive transport which does not require the assistance of proteins.

However, larger or polar substances require transport proteins to move across the membrane down their concentration gradient. If the substance moving into the cell requires a protein to facilitate its transport, it is likely not oxygen or carbon dioxide, as these gases can diffuse across the cell membrane without such assistance due to their small size and nonpolar nature.