466 KiB
466 KiB
G11 Pre-AP Biology
- Non-living
- Not capable of surviving on its own
- Acellular (Not made of cells)
- No cytoplasm, ribosomes, or membrane bound organelles.
- Doesn't produce energy.
- Essentially structures with genetic material (nucleic acid) and protein coating (capsid)
- Shapes: !Pasted image 20260911203414.png
- Bacteriophages are complex viruses which attach to bacteria.
- Replicates doesn't reproduce
- Instructs host cell to make copies of virus DNA
- Viroids are viruses without capsoids
- Prions are proteins that cause cells to misfold
Lytic and Lysogenic Cycles
- Lytic:
- Cycle:
- Virus attaches to host cell (either enters or inserts)
- Tricks host cell to making copies of viral DNA/viral parts
- Host cell assembles new viruses
- Host cell releases new virus (some hosts will lysis)
- Make viruses and then releases them
- Takes pieces of membrane with it
!Pasted image 20260911112321.png
- Cycle:
- Lysogenic:
- Cycle:
- Virus attaches to host cell
- Injects DNA
- Viral DNA integrates with host cells DNA (other viruses just enter nucleus)
- Host cell invokes mitosis (binary fission)
- Thus more host cells with viral DNA
- Virus stays dormant
- Provirus: Viral DNA attaches to DNA
- Leads into lytic cycle
- Specific to bacteriophages,
- Cycle:
Classification
- Size and shape
- Type of nucleic acid
- Presence/absence of outer envelope
Diagram
- Tail fiber shapes allow bacteriophages to infect different types of bacteria.
- Protein spike shapes allow it to enter different cells.
- Capsid
- Protective coating
- Nucleic Acid
- DNA or RNA
- Protein Spikes/Glycoprotein
- Allows them to attach and enter different cells
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- Allows them to attach and enter different cells
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