Chapter 13, Problem 1P

Interpretation Introduction

Interpretation:

The simple diffusion and facilitated diffusion needs to be compared.

Concept introduction:

Diffusion is the process in which particles moves from higher concentration region to lower concentration region. Diffusion is classified by the presence and absence of the facilitator molecule they are simple diffusion and facilitated diffusion.

Answer to Problem 1P

Simple diffusion is a passive process whereas facilitated diffusion is an active process that uses energy. Simple diffusion occurs without any intermediate molecule like channel protein or carrier molecules and facilitated diffusion occur across cells membrane through specific trans-membrane proteins. Molecules pass only in one direction of concentration region in simple diffusion. Whereas molecule in facilitated diffusion passes in both direction opposite to each other in the concentration region.

Explanation of Solution

Passive transport methods can be classified into two types via simple and facilitated diffusion. It is the process of transporting molecules across the cell membrane. Both the types are different from each other, as follows:

Simple Diffusion:

Simple diffusion is a type of diffusion where the particle moves from higher to lower concentration region.

Simple diffusion can transfer smaller and nonpolar particle like oxygen, carbon dioxide phospholipid bilayer.

Rate of diffusion is proportional to concentration gradient, permability of membrane molecule, temperature, molecular size.

Speed of simple diffusion is lower than facilitated diffusion.

Facilitated Diffusion:

Facilitated diffusion is a type of diffusion in which particles were transferred across biological membranes in assistance with a carrier molecule.

Large and polar ions can be transferred through transmembrane carrier protein in facilitated diffusion.

Rate of diffusion depends on the kinetics of carrier molecules and the rate of diffusion is high at a lower concentration.

Speed of facilitated diffusion is faster comparative to simple diffusion.

Conclusion

Both the diffusion methods are passive transport method that carries molecules across the membrane. Diffusion occurs through concentration gradient but in a different manner. Like, molecules move down in simple diffusion and molecules move in unfacilitated diffusion. Simple diffusion allows direct transportation of molecules whereas facilitated diffusion transports molecules through transmembrane proteins.