Pages 476 495 A Rhinovirus The Flu What is a Virus Nonliving particles that cant reproduce nucleic acids DNA or RNA enclosed in a protein coat Smaller than the smallest bacterium ID: 692410
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Slide1
Chapter 18 Viruses and Bacteria
Pages 476 - 495Slide2
A Rhinovirus Slide3
The FluSlide4Slide5
What is a Virus??
Non-living particles that can’t reproduce
nucleic
acids
(DNA or RNA)
enclosed
in a protein coat
Smaller than the smallest bacterium
Do
replicate on their
own
Must have a hostSlide6
Viruses
Don’t
carry out
respiration, develop or grow
~~Influenza, smallpox, HIV, Herpes I and Herpes II
Can mutate to become more dangerous
Bacteriophages infect bacterial cells
All living organisms can contract viruses
Some are species specific – HIV only affects humans
Have to have a host to replicate
Found soil, air waterSlide7
Structure of Bacteriophage that Infects BacteriaSlide8
Bacteriophage Slide9
Bacteria Phages Amplified with Electron MicroscopeSlide10
Virus Amplified by Electron MicroscopeSlide11
Viruses Replicate (NOT real reproduce)Slide12
Viral Replication Cycles
Lytic Cycle
Lysogenic CycleSlide13
Lytic Cycle
A virus takes over a
h
ost’s genetic material
The cell bursts (
Lysis
) and viruses spread
Uses its structures and energy to replicate many viruses Slide14
Lytic CycleSlide15
Lysogenic Cycle
** The virus’s nucleic acid (DNA/RNA) is integrated into the host cell’s chromosome
**
Th
e virus lay “dormant” as the cell reproduces itself
**
The
cell is then called a provirusSlide16
Lysogenic Cycle
After the virus has inserted its genetic material (Step 1)Slide17Slide18
Replication Activity
Compared to a FactorySlide19
Types of VirusesSlide20
Tobacco Mosaic virus causes leaves to turn yellow and can’t be sold at marketSlide21
Proviruses
(Undergo the lysogenic cycle)
Herpes Zoster (chicken pox), Herpes
simplex
I (cold Sores),
herpes simplex II
(Genital Herpes),
and
hepatitis B (affects liver)Slide22
Retrovirus
RNA viruses—RNA being their only
HIV
that causes the disease
AIDSSlide23
Retrovirus HIV
Infects
white blood
cells (remember B and T Cells!!!)
Released
into the blood stream by
exocytosis
and infect other white blood cells.Slide24
HIVSlide25
Cancer and Viruses
Viruses linked to cancer
disrupt
mitosis
HPV is the most common
Human
Papilloma Virus causes genital warts and accounts for about 76% of cervical cancersSlide26
BacteriaSlide27
Bacteria - Prokaryotes
Archaebacteria
– The extremist; Oldest;
salt-loving; heat-loving
Eubacteria
Some are photosynthetic - photosynthesis
Some undergo chemosynthesis – break down surrounding organic compounds for food
Some are heterotrophs – “eat” their own foodSlide28
Bacteria Reproduction
Binary Fission Conjugation
Type of Reproduction Asexual Sexual
--------------------------------------------------------------------------------------------
How it Happens One bacterium one bacterium
makes a copy of transfers
its chromosomes chromosomes to
and splits into two another bacterium through
pili
-----------------------------------------------------------------------------------------------
Description of Cells Genetically Genetically different
Produced identicalSlide29
Bacteria
Flagellum
Ribosome
Cytoplasm
Chromosome
capsule
Cell Wall
Cell
Membrane
PiliSlide30
Bacteria Adaptations
Endospore
forms around bacteria during harsh conditions
Cells grow and reproduce
Can produce toxins
Botulism (food poisoning), anthrax (lives in soil)
Can mutate quickly to environmental change and become more dangerousSlide31
Harmful
Some make you sick and can
bcome
antibiotic resistant
Strep throat
Food poisoning
Some Pneumonias
Lyme disease
Tuberculosis
CavitiesSlide32
Helpful to Humans
Nitrogen fixation (plant root convert nitrogen gas into usable nitrogen for the plant)
Return nutrients to soil
Produce oxygen
Production of cheese, yogurt and pickles
E. coli
in the intestines
Used in farming, medicine and food industry