466 KiB
466 KiB
G11 Pre-AP Biology Non-living as:
- Not capable of surviving on its own.
- Acellular.
- No cytoplasm, ribosomes, or membrane bound organelles.
- Doesn't produce energy (no metabolism).
- No self reproduction.
- No homeostasis. Essentially structures with genetic material (nucleic acid) and protein coating (capsid). !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 capsids. Prions are proteins that cause cells to misfold.
Lytic cycle:
- 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 Lysogenic cycle:
- 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,
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 acts as a protein protective coating.
Nucleic acid which is either DNA or RNA.
Protein spikes/glycoprotein which allows them to enter different types of cells.
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