Viral Structure and Replication
1. Viral Structure
Hepadnaviruses
Enveloped
Virus Particle: Contains ds/ssDNA, unusual
Covering-Capsid: Protein coat surrounded by capsomers.
Envelope: (Not found in all viruses).
Central Core – Nucleic Acid Molecules: (DNA or RNA) Double/single strand DNA/RNA, every viron has it.
Matrix Proteins: Enzymes not found in all viruses.
HepB
- Break in skin/blood, STD
- Flu-like symptoms, jaundice
2 Shapes
- Helical
- Icosahedral
Non-Enveloped Viruses
Adenoviruses/Papillomaviruses/Polyomaviruses/Parvoviruses
Adeno
- Infect lymphoid
Antimicrobial Agents and Microbial Virulence Factors
Chapter 9: Sanitization and Disinfection
Disinfection in Public Places
Action of Antimicrobial Agents:
- Alteration of cell wall or cytoplasmic membrane
- Interference with protein and nucleic acid structures
Effectiveness of Antimicrobial Agents:
- High-Level: Kill all pathogens (besides prions)
- Intermediate-Level: Kill fungal spores, protozoan cysts, viruses, and pathogenic bacteria.
- Low-Level: Kill vegetative bacteria, fungi, protozoa, and some viruses.
Antimicrobial Agents: Heat, dry heat, refrigeration and
Read MoreOrganization and Function of the Central Nervous System
Central Nervous System (CNS)
Brain and Spinal Cord
Cephalization
- Evolutionary development of the anterior CNS
- Increased number of neurons in the head
- Highest level reached in the human brain
Embryonic Development
- Brain and spinal cord begin as a neural tube
- Three primary vesicles form at the anterior end:
- Prosencephalon (forebrain)
- Mesencephalon (midbrain)
- Rhombencephalon (hindbrain)
- Posterior end becomes the spinal cord
Embryonic Development: Five Secondary Brain Vesicles
- Forebrain (prosencephalon) divides into:
Microbiology Lab Techniques & Procedures
Pasteur’s Gooseneck Flask Experiment
Gram Stain
Mechanism:
Cellular Respiration and Photosynthesis: An Overview
Universal Energy Currency
ATP acts as a ‘Uniercersal Energy Currency’ as it transfers energy to biochemical reactions in all living organisms.
Hydrolysis of ATP
Energy release = hydrolysis of ATP > ADP + inorganic phosphate (Pi)
Exergonic reaction catalysed by ATPase = removal of terminal phosphate
Always coupled with an endergonic reaction where energy is transferred
Soluble molecule which can be transported within a cell but can’t leave it
Transfers energy > processes requiring energy: nervous
Read MoreMicrobial Mechanisms of Pathogenicity: Understanding Bacterial Virulence
Microbial Mechanisms of Pathogenicity
Introduction
Pathogenicity: The ability to cause disease.
Virulence: The extent of pathogenicity.
Four Virulence Factors
- Adhesion factors
- Extracellular enzymes
- Toxins
- Antiphagocytic factors
Number of Invading Microbes
ID50: Infectious Dose for 50% of the test population.
LD50: Lethal Dose (of a toxin) for 50% of the test population.
Example: Bacillus anthracis (Creates Endospores)
| Portal of Entry | ID50 |
|---|---|
| Skin | 10-50 endospores |
| Inhalation | 10,000-20,000 endospores |
| Ingestion | 250,000-1, |