Vocabulary Chapter 21 Sec. 21.1- Viruses
Virus- segments of nucleic acids contained in a protein coat.
-Not considered living organisms.
Capsid- the protein coat around a virus
Envelope- a membrane around the capsid
- help virus enter a cell
Glycoprotein- proteins with attached carbohydrate molecules
Bacteriophage- a virus that infects bacteria
Pathogen- Any agent that causes disease
Lytic Cycle- the cycle of viral infection, replication and cell destruction
- creates more viruses using cell structures
Provirus- The viral genes are inserted in the host chromosomes
- Creates more cells that the viral genes are integrated into the original chromosomes
Lysogenic Cycle- after infection from a provirus, cells divide resulting in two infected host cells
Emerging Virus- viruses that evolve in geographically isolated areas and are pathogenic to humans
Prion- particles composed of proteins and have no nucleic acids (do not have genes)
- causes proteins to fold in a deformed manner affecting their function
Viroid- a single strand of RNA that has no capsid
- important infectious agents in plants
Sec. 21.2- Bacteria
Pilus- short thick outcroppings on bacteria that enable them to attach to other cells
Bacillus- rod shaped cell
Coccus- round shaped cell
Spirillum- spiral cell shape
Capsule- a gel like layer outside the cell wall and membrane in many bacteria
Antibiotic - chemicals that interfere with life processes in bacteria
Endospore- dormant bacterial cell enclosed by a tough coat that is resistant to environmental stress
Conjugation- a process where two organisms exchange genetic material
Anaerobic- oxygen free
Aerobic- in the presence of oxygen
Toxin- chemical compounds, which are poisonous to eukaryotic cells