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

1. Overview of Cell Biology

Overview of Tissue Structures

Cell Biology

1. Overview of Cell Biology

Overview of Tissue Structures

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Multiple Choice

In skeletal muscle tissue, what are the light bands (I bands) primarily composed of?

Actin filaments

Elastin fibers

Myosin filaments

Collagen fibers

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Understand the structure of skeletal muscle tissue: Skeletal muscle is composed of repeating units called sarcomeres, which are the functional units of muscle contraction. Sarcomeres are made up of alternating light (I bands) and dark (A bands) regions.

Recall the composition of the I band: The I band is the light region of the sarcomere and is located on either side of the Z line. It contains thin filaments but no thick filaments.

Identify the primary protein in thin filaments: Thin filaments are primarily composed of actin, a globular protein that forms long filaments. Actin interacts with myosin during muscle contraction.

Eliminate incorrect options: Elastin fibers and collagen fibers are structural proteins found in connective tissues, not in the sarcomere. Myosin filaments are part of the thick filaments found in the A band, not the I band.

Conclude that the light bands (I bands) are primarily composed of actin filaments, as they are the main component of the thin filaments in this region.