Viral Immunity and Pathogenesis: Host Defense Mechanisms and Infection Outcomes
Host Defense Mechanisms Against Viruses
Innate, Intrinsic, and Adaptive Immunity
- Innate Immunity: Non-specific, immediate response. Uses Pattern Recognition Receptors (PRRs) to detect Pathogen-Associated Molecular Patterns (PAMPs).
- Intrinsic Immunity: Always present in cells (pre-existing defenses).
- Examples: TRIM proteins, MxA, Tetherin, autophagy, apoptosis.
- Adaptive Immunity: Specific, develops after infection.
- Two arms: T cells (cell-mediated) and B cells (antibody-mediated/humoral).
Pathogen-Associated
Read MoreComparative Adaptations for Respiratory Gas Exchange
The Process of Gas Exchange
Gas exchange is the vital physiological process by which oxygen ($ ext{O}_2$) from the environment is taken into the body and carbon dioxide ($ ext{CO}_2$), a waste product of cellular respiration, is removed. In animals, this process typically occurs across specialized respiratory surfaces, such as:
- Lungs (mammals, birds, reptiles)
- Gills (fish, some amphibians)
- Skin (some amphibians, invertebrates)
Oxygen diffuses across thin, moist membranes into the bloodstream or directly
Read MoreMolecular Genetics: Key Concepts and Mutation Effects
Molecular Genetics Fundamentals
Cellular Transformation and Key Enzymes
Transformation studies demonstrate the ability to transition from non-disease-causing to disease-causing states, often involving the uptake of genetic material.
Enzyme Definitions
- Enzyme that degrades DNA: DNase
- Enzyme that degrades protein: Protease
- Enzyme that degrades RNA: RNase
Cell Types and Ploidy
- Somatic Cells: Non-reproductive cells (diploid).
- Gametes: Reproductive cells (haploid), containing half the amount of DNA as somatic
Plant Nutrition Mechanisms: Photosynthesis and Nutrient Uptake
Core Functions of Organic Molecules
Plants require organic molecules for two primary functions:
- To obtain the energy required for vital functions.
- To increase size, develop, and form new organs.
Autotrophic Organisms
In addition to plants, other organisms are autotrophs, including many protists, Monera, and algae.
Phases of Plant Nutrition
Plant nutrition involves two main parts:
- Organic Synthesis (Photosynthesis): The process by which light energy is transformed into chemical energy, converting inorganic
How Chinook Salmon Gills Achieve 90% Oxygen Extraction
Chinook Salmon Respiration: Challenges and Adaptations
The Chinook salmon (Oncorhynchus tshawytscha), a member of the class Actinopterygii (ray-finned bony fishes), is an anadromous species native to the cold rivers and coastal waters of the North Pacific Ocean. This species begins life in freshwater streams, migrates to marine environments for adult life, and later returns to freshwater to spawn. Living in an aquatic environment poses considerable physiological challenges for gas exchange, primarily
Read MoreFundamentals of Ecology: Ecosystems and Environmental Factors
Ecological Pyramids: Structure and Representation
The ecological pyramid is a form of representation used to show how various characteristics of trophic levels, such as production or biomass, change when moving from one level to another.
Each trophic level is represented by a rectangle. The rectangle forming the base of the pyramid represents the producers (manufacturers), whose resources are available to other trophic levels. The length of the base of each rectangle is proportional to the measured
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