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MICROBES! Bacteria, MICROBES! Bacteria, Viruses, Protists, and Viruses, Protists, and
FungiFungi
Chapters 21-23March 2011
Chapter 20 Chapter 20 VocabularyVocabulary
1. Virus
2. Pathogen
3. Glycoproteins
4. Lytic cycle
5. Provirus
6. Lysogenic
7. Prions
8. Viroids
9. Pili
10.Bacillus/Coccus/Spirillum
11. Capsule
12. Antibiotics
13.Endospores
14. Conjugation
15. Aerobic/Anaerobic
1. Virus
•so small they can be seen only with the aid of a powerful electron microscope.
•simplest viruses contain only a few genes, whereas the most complex may have more than a hundred genes
•Most viruses infect only a very specific kind of cell.
viruses that infect bacteria are called bacteriophages.
Latin for poison!
2. Pathogen
Disease causing agents! Bacteria viruses fungi and protists!
3. Glycoproteins
Receptor molecules on the outside of the virus.
Proteins and carbohydrates attached.
Used for recognition on the cell membrane or cell wall.
4. Lytic cycle
In a lytic infection, a virus enters a bacterial cell, makes copies of itself, and causes the cell to burst, or lyse.
Bacteriophage T4 is an example of a bacteriophage that causes such an infection.
The host cell lyses, releasing hundreds of virus particles that go on to infect other cells.
5. Provirus
The virus that has become part of the DNA of the host cell. also called a prophage.
6. Lysogenic
In a lysogenic infection a host cell is not immediately taken over. The viral DNA is then copied along with the host DNA without
damaging the host. Viral DNA multiplies as the host cells multiply. In this way, each generation of daughter cells derived from the
original host cell is infected. Bacteriophage DNA that becomes embedded in the bacterial host’s
DNA is called a prophage. Influences from the environment—radiation, heat, etc—trigger the
prophage to become active.
7. Prions
Miss folded proteins
Cause disease
No nucleic acid involved!
Mad Cow disease is an example prions, short for “protein infectious particles.”
Prions are misfolded proteins in the brain that cause a chain reaction of misfolding in other normal proteins they contact, eventually clogging the brain tissue and causing disease
Many animals, including humans, can become infected with prions
8. Viroids
Small RNA segments
Cause disease in plants
Possibly can infect animals
9. Pili Attachment structures
Also used for reproduction
10.Bacillus
rods
10. Coccus
Round
10. Spirillum
spiral bacteria
often cause bad diseases!
11. Capsule
Some bacteria have a slimy layer of polysaccharides and polypeptides, allowing them to attach to objects and providing protection.
12. Antibiotics Antibiotics
interfere with bacterial cell functions!
13.Endospores
Outer protective covering.
Makes the bacteria more pathogenic!
Bacterial endospores are highly resistant to hostile physical and chemical
conditions.
14. Conjugation
Transfer of genetic material from one bacteria to another.
New genetic recombination's occur
15. Aerobic/Anaerobic
Aerobic: Require oxygen
Anaerobic: Require No Oxygen!