CBA 1 - Viruses, Bacteria and Fungi

Viruses consist of:
- Nucleic acids (DNA/RNA)
- Capsids (Protein covering)
Viruses are acellular because they do not consist of cells.
Types of viruses:
- Naked virus: Contains capsid and nucleic acids.
- Enveloped virus: Contains capsid, nucleic acids and a membrane.
Viral Reproduction:
- Viruses attach to host cells and insert their nucleic acids.
- The host cell uses the viral nucleic acids to make new virus components.
- The components assemble into new viruses and are released.
Viral Nucleic Acid Incorporation:
- When viruses insert their nucleic acids into the host cell, the nucleic acids can be incorporated into the host's DNA and remain dormant.
Effects of Viruses on Host Cells:
- Disrupt normal cell function.
- Damage host DNA causing mutations/cancer.
- Burst the cell when they are released.
Host Specificity:
- Viruses are host-specific because they can only infect one type of cell in one species.
Bacteriophages:
- Viruses that only infect bacteria.
- Structure includes: capsid head, nucleic acids, collar, tail sheath, tail fiber, base plate and protein spikes.
Living vs. Non-Living Debate:
- Non-living aspect: Viruses do not respire or reproduce without a host cell.
- Living aspect: Viruses can reproduce inside a host cell.

Bacteria (prokaryotes) Characteristics:
- Unicellular
- No membrane-bound organelles
Types of Bacteria (Shapes):
- Coccus
- Bacillus
- Vibrio
- Spirillum

Function:
- Acids and enzymes are released into surroundings.
- Organic material is broken down into nutrients.
- Necessary nutrients are absorbed.
Structure:
- Mycelium: Network of filaments that composes the body of the fungus.
- Hyphae: Individual filaments of the mycelium.
- Fruiting body: Visible part that produces spores.
Cell Wall Composition:
- Chitin is the cell wall of fungi.
Rhizopus Growth Conditions:
- Warm
- Dark
- Damp
Structure of Rhizopus:
- Spores
- Sporangium
- Columella
- Sporangiophore
- Stolon
- Rhizoids