Table of contents
- 1. Introduction to Biology2h 42m
- 2. Chemistry3h 40m
- 3. Water1h 26m
- 4. Biomolecules2h 23m
- 5. Cell Components2h 26m
- 6. The Membrane2h 31m
- 7. Energy and Metabolism2h 0m
- 8. Respiration2h 40m
- 9. Photosynthesis2h 49m
- 10. Cell Signaling59m
- 11. Cell Division2h 47m
- 12. Meiosis2h 0m
- 13. Mendelian Genetics4h 44m
- Introduction to Mendel's Experiments7m
- Genotype vs. Phenotype17m
- Punnett Squares13m
- Mendel's Experiments26m
- Mendel's Laws18m
- Monohybrid Crosses19m
- Test Crosses14m
- Dihybrid Crosses20m
- Punnett Square Probability26m
- Incomplete Dominance vs. Codominance20m
- Epistasis7m
- Non-Mendelian Genetics12m
- Pedigrees6m
- Autosomal Inheritance21m
- Sex-Linked Inheritance43m
- X-Inactivation9m
- 14. DNA Synthesis2h 27m
- 15. Gene Expression3h 20m
- 16. Regulation of Expression3h 31m
- Introduction to Regulation of Gene Expression13m
- Prokaryotic Gene Regulation via Operons27m
- The Lac Operon21m
- Glucose's Impact on Lac Operon25m
- The Trp Operon20m
- Review of the Lac Operon & Trp Operon11m
- Introduction to Eukaryotic Gene Regulation9m
- Eukaryotic Chromatin Modifications16m
- Eukaryotic Transcriptional Control22m
- Eukaryotic Post-Transcriptional Regulation28m
- Eukaryotic Post-Translational Regulation13m
- 17. Viruses37m
- 18. Biotechnology2h 58m
- 19. Genomics17m
- 20. Development1h 5m
- 21. Evolution3h 1m
- 22. Evolution of Populations3h 52m
- 23. Speciation1h 37m
- 24. History of Life on Earth2h 6m
- 25. Phylogeny2h 31m
- 26. Prokaryotes4h 59m
- 27. Protists1h 12m
- 28. Plants1h 22m
- 29. Fungi36m
- 30. Overview of Animals34m
- 31. Invertebrates1h 2m
- 32. Vertebrates50m
- 33. Plant Anatomy1h 3m
- 34. Vascular Plant Transport1h 2m
- 35. Soil37m
- 36. Plant Reproduction47m
- 37. Plant Sensation and Response1h 9m
- 38. Animal Form and Function1h 19m
- 39. Digestive System1h 10m
- 40. Circulatory System1h 57m
- 41. Immune System1h 12m
- 42. Osmoregulation and Excretion50m
- 43. Endocrine System1h 4m
- 44. Animal Reproduction1h 2m
- 45. Nervous System1h 55m
- 46. Sensory Systems46m
- 47. Muscle Systems23m
- 48. Ecology3h 11m
- Introduction to Ecology20m
- Biogeography14m
- Earth's Climate Patterns50m
- Introduction to Terrestrial Biomes10m
- Terrestrial Biomes: Near Equator13m
- Terrestrial Biomes: Temperate Regions10m
- Terrestrial Biomes: Northern Regions15m
- Introduction to Aquatic Biomes27m
- Freshwater Aquatic Biomes14m
- Marine Aquatic Biomes13m
- 49. Animal Behavior28m
- 50. Population Ecology3h 41m
- Introduction to Population Ecology28m
- Population Sampling Methods23m
- Life History12m
- Population Demography17m
- Factors Limiting Population Growth14m
- Introduction to Population Growth Models22m
- Linear Population Growth6m
- Exponential Population Growth29m
- Logistic Population Growth32m
- r/K Selection10m
- The Human Population22m
- 51. Community Ecology2h 46m
- Introduction to Community Ecology2m
- Introduction to Community Interactions9m
- Community Interactions: Competition (-/-)38m
- Community Interactions: Exploitation (+/-)23m
- Community Interactions: Mutualism (+/+) & Commensalism (+/0)9m
- Community Structure35m
- Community Dynamics26m
- Geographic Impact on Communities21m
- 52. Ecosystems2h 36m
- 53. Conservation Biology24m
10. Cell Signaling
Signal Amplification
Problem 9a`
Textbook Question
Steroid hormones, like most lipid-soluble signaling molecules, are processed directly. How does the absence of a signal transduction cascade in the processing of steroid hormones affect (a) signal amplification?

1
Understand the nature of steroid hormones: Steroid hormones are lipid-soluble, meaning they can easily pass through the cell membrane without the need for a receptor on the cell surface.
Recognize the direct action of steroid hormones: Once inside the cell, steroid hormones typically bind to specific intracellular receptors, forming a hormone-receptor complex that can directly influence gene expression in the nucleus.
Identify the absence of a signal transduction cascade: Unlike water-soluble hormones, which often require a series of steps (signal transduction cascade) to relay and amplify the signal, steroid hormones act directly without these intermediary steps.
Consider the impact on signal amplification: In signal transduction cascades, each step can amplify the signal, leading to a larger cellular response. The absence of such a cascade in steroid hormone action means there is less opportunity for amplification, resulting in a more direct but potentially less amplified response.
Reflect on the biological implications: The direct action of steroid hormones allows for precise regulation of gene expression, but the lack of amplification means that the response is more dependent on the concentration of the hormone itself rather than the amplification through a cascade.

This video solution was recommended by our tutors as helpful for the problem above
Video duration:
1mPlay a video:
Was this helpful?
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Steroid Hormones
Steroid hormones are lipid-soluble molecules derived from cholesterol. They can easily pass through cell membranes due to their hydrophobic nature. Once inside the cell, they typically bind to specific intracellular receptors, forming a hormone-receptor complex that directly influences gene expression by acting on DNA in the nucleus.
Recommended video:
Guided course
Plant Hormones and Senescence
Signal Transduction Cascade
A signal transduction cascade is a series of molecular events initiated by the binding of a signaling molecule to a receptor on the cell surface. This process often involves multiple steps, including the activation of proteins and second messengers, leading to a large-scale cellular response. It allows for signal amplification, where a small number of signaling molecules can produce a significant cellular response.
Recommended video:
Guided course
Phosphorylation Cascades
Signal Amplification
Signal amplification refers to the process by which a single signaling molecule can trigger a large cellular response. In typical signal transduction pathways, each step can activate multiple downstream molecules, exponentially increasing the signal's strength. In the absence of a cascade, as with steroid hormones, this amplification is limited, as the hormone directly influences gene expression without intermediate steps.
Recommended video:
Guided course
Signal Amplification
Related Videos
Related Practice