Table of contents

1. Overview of Cell Biology2h 49m
2. Chemical Components of Cells1h 14m
3. Energy1h 33m
4. DNA, Chromosomes, and Genomes2h 31m
5. DNA to RNA to Protein2h 31m
6. Proteins1h 36m
7. Gene Expression1h 42m
8. Membrane Structure1h 4m
- The Lipid Bilayer
  38m
- Membrane Proteins
  25m
9. Transport Across Membranes1h 52m
10. Anerobic Respiration1h 5m
11. Aerobic Respiration1h 11m
12. Photosynthesis52m
13. Intracellular Protein Transport2h 18m
14. Cell Signaling1h 28m
15. Cytoskeleton and Cell Movement1h 39m
16. Cell Division3h 5m
17. Meiosis and Sexual Reproduction50m
18. Cell Junctions and Tissues48m
19. Stem Cells13m
- Stem Cells
  13m
20. Cancer44m
21. The Immune System1h 6m
22. Techniques in Cell Biology1h 41m

9. Transport Across Membranes

Principles of Transmembrane Transport

Cell Biology

9. Transport Across Membranes

Principles of Transmembrane Transport

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Multiple Choice

Facilitated diffusion differs from simple diffusion because why?

Facilitated diffusion requires energy to move substances across the membrane

Facilitated diffusion requires a protein to move substances across the membrane

Simple diffusion requires energy to move substances across a membrane

. Simple diffusion requires a protein to move substances across the membrane

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Verified step by step guidance

Understand the concept of diffusion: Diffusion is the movement of molecules from an area of higher concentration to an area of lower concentration. It is a passive process, meaning it does not require energy.

Differentiate between simple diffusion and facilitated diffusion: Simple diffusion occurs directly across the phospholipid bilayer without the need for any additional components. Facilitated diffusion, however, requires the assistance of specific proteins to transport substances across the cell membrane.

Identify the role of proteins in facilitated diffusion: In facilitated diffusion, transport proteins such as channel proteins or carrier proteins help move substances across the cell membrane. These proteins provide a pathway for certain molecules that cannot easily pass through the lipid bilayer.

Clarify the energy requirement: Both simple diffusion and facilitated diffusion are passive processes, meaning they do not require energy input from the cell. This is a key distinction from active transport, which does require energy.

Conclude with the correct statement: Facilitated diffusion differs from simple diffusion because it requires a protein to move substances across the membrane, whereas simple diffusion does not require such proteins.