Introduction: Understanding Simple and Facilitated Diffusion
Cell membranes act as selective barriers, regulating the movement of substances in and out of cells. Two key transport mechanisms that facilitate this movement are simple diffusion and facilitated diffusion. Simple Diffusion is a passive process where molecules move directly across the lipid bilayer due to a concentration gradient. Facilitated Diffusion, on the other hand, requires specific transmembrane proteins to assist in transporting larger or charged molecules across the membrane.
In this article, we will explore the Differences Between Simple Diffusion and Facilitated Diffusion in detail.
Difference Between Simple Diffusion and Facilitated Diffusion
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FAQs on Difference Between Simple Diffusion and Facilitated Diffusion: Definition and Process
1. What is the difference between simple diffusion and facilitated diffusion?
Simple diffusion occurs directly through the cell membrane without assistance, whereas facilitated diffusion requires transport proteins to move molecules across the membrane.
2. Does facilitated diffusion require energy (ATP)?
No, facilitated diffusion is a passive process and does not require ATP. It relies on concentration gradients to move molecules.
3. What type of molecules move through simple diffusion?
Small, non-polar molecules like oxygen (O₂) and carbon dioxide (CO₂) move through simple diffusion.
4. What type of molecules move through facilitated diffusion?
Large, polar, or charged molecules such as glucose, amino acids, and ions (Na⁺, K⁺) require facilitated diffusion to cross the membrane.
5. How does facilitated diffusion work?
Facilitated diffusion uses channel and carrier proteins to help molecules cross the cell membrane without requiring energy.
6. What is an example of simple diffusion in the human body?
Gas exchange in the lungs, where oxygen moves into the blood and carbon dioxide exits, is an example of simple diffusion.
7. What is an example of facilitated diffusion in the human body?
Glucose uptake into cells via GLUT transporters is an example of facilitated diffusion.
8. What factors affect the rate of simple diffusion?
The concentration gradient, temperature, molecular size, and membrane permeability affect the rate of simple diffusion.
9. What factors affect the rate of facilitated diffusion?
The availability of transport proteins, concentration gradient, and molecule size influence the rate of facilitated diffusion.
10. Why can’t glucose pass through the membrane via simple diffusion?
Glucose is a large, polar molecule, so it requires carrier proteins to cross the hydrophobic lipid bilayer.
