Download Ch. 18

Ch. 18 Viruses and Bacteria
Name:
18.1 What is a Virus?
1. Virus–
2. Host Cell –
A. Viral Structure
1. A virus has an inner core of ________________________
2. Capsid –
B. Attachment to a host cell
1. Before a virus can replicate, it must __________________ to a host cell
2. Viral shapes:
1. Polyhedral virus
(warts)
2. Tobacco mosaic
virus
3. AIDS virus
4. Bacteriophage (T4)
– virus that infects a
bacterium ( E. coli)
C. Attachment is a specific process
1. Each virus has a specifically shaped attachment protein and can only attach to
_______________________________________l. Ex: T4 phage and E. coli
D. Viral Replication Cycles
1. . Lytic cycle –
2. Lysogenic cycle –
Lysogenic Cycle
Lytic Cycle
3. Provirus a. Diseases: Herpes simplex I – cold sores, Herpes simplex II – genital herpes,
Hepatitis B, Chicken pox
E. Retroviruses –
1. Reverse transcriptase –
G. HIV: An infection of white blood cells – an infected individual may not notice symptoms
because the provirus _________________________________, allow them to still function.
H. Viruses and Cancer – Ex: hepatitis B and liver cells
I. Plant Viruses – spread by cutting with infected tool. Ex: Tobacco mosaic virus
18.2. Kingdoms Archaebacteria and Eubacteria
A. Diversity of Prokaryotes
1. ___________________ - live in extreme environments
a. Methane producing bacteria live in _____________
______________________________________________________
b. Salt-loving bacteria live in the some __________
___________________
c. ________________________________________________________ live in deep
ocean vents where water is above 100o C
2. ___________________: the heterotrophs are decomposers
and parasites
3. ___________________ bacteria contain chlorophyll and
live in ponds and streams.
Ex: Cyanobacteria
4. ___________________ ___________________ - break down and release the energy of
inorganic compound containing S and N
B. What is a Bacterium? – unicellular, prokaryote
1. Shapes:
a).
b).
c).
2. Patterns:
a).
c).
c).
3. Reproduction:
Binary fission
a). ___________________
___________________ – a process of cell division in
which 1 bacteria splits into two identical copies.
(reproduces exponentially up to 1 every 20 minutues)
b). ___________________ – a form of
sexual reproduction in which genetic information is
exchanged via pili (p 506) .
C. Adaptations in bacteria
1. ___________________ _________________ –
require oxygen for respiration
2. ___________________ _________________ – are killed in oxygen
Ex: botulism
D. Survival
1. ___________________ – tough coat containing
genetic information that resists harsh environments
a). Ex: ___________________ spores can
contaminate food by producing deadly “toxins”
E. The Importance of Bacteria
1. ___________________ ___________________ –
part of the Nitrogen cycle that converts N2 to ammonia NH3
2. Foods and medicines
a). ___________________ – cheese, pickles, vinegar …
b). ___________________ – Insulin, HGH, penicillin (mold)
3. ___________________ – a possibly deadly poison