Download Objective Set 7

Unit 3
Viruses and
Eukaryotic Microbes
Unit 3-page 1
FOM Chapter 14 – The Viruses and Virus-Like
Agents
Preview: In Chapter 14, we will consider several features of the viruses, including
their structure and shapes. We will see how viruses are classified, how they
produce more of themselves, and how some viruses can cause human tumors
and possibly cancers.
CBS – 60 Minutes
The Ebola Hot Zone
Lara Logan traveled to Liberia (11/09/2014) to report on American healthcare workers
on the frontline of the Ebola outbreak.
https://www.youtube.com/watch?v=mrADU-L65GI
Homework extra credit assignment
■ Viruses Are Not Part of the Tree of Life
 They are not cells (acellular)
 Are they living?
Characteristic of Life
Prokaryotes &
Eukaryotes
Complex structural organization
Yes
Homeostasis/metabolism
Yes
Growth and development
Yes
Response to environment
Yes
Reproduction
Yes
Adaptation
Yes
Transfer and transformation of energy
Yes
Unit 3-page 2
Viruses
KEY CONCEPT 14.2
Viruses Have a Simple Structural Organization
 Viruses Are Tiny Infectious Agents
Eukaryotic cells
Prokaryotic cells
Viruses
Size
 Diseases caused by viruses =
 Many cause zoonotic diseases (zoonosis)
Animal
(bat)
Other
animal
(bat)
Human
 Virus Structure
(A) Nonenveloped form
(B) Enveloped form
Fig. 14.6
Unit 3-page 3
 Viruses Are Grouped by Their Shapes
Fig. 14.7
■ Viruses Have a Host Range and Tissue Specificity
 Host range
 Cell/Tissue specificity
 What is a virus?
Unit 3-page 4
KEY CONCEPT 14.3
Viruses Can Be Classified by Their Genome
Classes of Human (Animal) Viruses—by nucleic acid type
(modified from Figure 14.8)
Class
Nucleic Acid
Disease Examples
dsDNA
ssDNA
dsRNA
ssRNA
(+ sense)
ssRNA
(– sense)
ssRNA
(+ sense)
(+rtase)
dsDNA
(+rtase)
ds = double-stranded; ss = single-stranded; rtase = reverse transcriptase
Unit 3-page 5
Key Concepts 14.2 – 14.3
SUMMARY
What are viruses and how are they classified?
KC 14.2 Are viruses alive?
KC 14.2 Virus structure is
acellular but they have a
genome
KC 14.3 Viruses are
catalogued by their nucleic
acid type
KC 14.2 Viruses have a
host range and cell/tissue
tropism
Viruses are small, obligate infectious agents
Viruses are infectious agents with a genome and capsid,
and they are separated into different groups
based on their genome
Unit 3-page 6
Tulip-O-Mania!
Viruses are not all pathogens.
KEY CONCEPT 14.4
Viral Replication Follows a Set of Common Steps
2.
Latent infection
1.
Productive infection
3.
5.
4.
Unit 3-page 7
■ The Replication of Bacteriophages Can Follow One of Two Cycles
Bacteriophage (phage) structure
 Significance of phages
Lytic pathway
(productive infection)
Numerous
phages
Phage
Lysogenic pathway
Lytic pathway
(latent infection)
(productive infection)
Phage
DNA
Phage
prophage
Unit 3-page 8
Numerous
phages
 Animal Virus Replication Often Results in a Productive Infection
 dsDNA viruses
 Herpesviruses
Virus
1.
Host cell
Cytoplasm
Cell nucleus
2a.
Productive
infection
cycle
5.
2b.
3.
4.
Unit 3-page 9

Other Viruses Also Involve a Productive Infection
Virus Class
Genome
Example
■ Some Viruses Produce a Latent Infection
Productive
infection
HSV-1
HIV
Latent infection
Unit 3-page 10
■ Virus Infections Trigger Disease
 Cell death
 Cell dysfunction
■ Antiviral Drugs Can Interfere with Replication
Productive
infection
HSV-1
HIV
Latent infection
Unit 3-page 11
 Antibiotics Are Not Useful Against Viral Infections and Disease
Characteristic
Antibiotic
Source
Mode of action
Uses
Resistance
Unit 3-page 12
Antiviral
Key Concept 14.4
SUMMARY
How do viruses replicate?
KC 14.4 Viruses replicate in
a five-step process
KC 14.4 Bacteriophages
infect bacterial cells
through a lytic cycle or
lysogenic cycle
KC 14.4 All viruses
undergo a productive
infection
KC 14.4 Antiviral drugs
(synthetic and natural)
interfere with viral
replication
KC 14.4 Some viruses can
undergo a latent infection
before a productive
infection develops
KC 14.4 Antibiotics do not
affect virus replication
Virus replication requires host cells
Viruses replicate by taking over
a host cell and using the cell’s
machinery to build more viruses
Unit 3-page 13
CBS Evening News
Killing Cancer
In this broadcast on 03/29/2015, brain cancer patients in a Duke University
clinical trial are followed during their treatment with a polio virus engineered to
kill cancer cells.
https://www.youtube.com/watch?v=acrlYaAqAKU
KEY CONCEPT 14.6
Some Viruses Are Associated with Human Tumors and Cancers
 Cancer Is an Uncontrolled Growth of Cells
Unit 3-page 14
Fig. 14.7
 Viruses Are Associated with Human Tumors and Cancers
Oncogenic (DNA Tumor) Virus
Human Tumor/Cancer
■ Oncogenic Viruses Transform Infected Cells

Oncogene
Host cell
cytoplasm
Oncogene
Tumor
development
Cell
nucleus
Unit 3-page 15
Key Concept 14.6
SUMMARY
How do some viruses trigger tumor formation and
cancer development?
KC 14.6 Many
environmental, genetic,
and biological factors can
cause tumor formation
KC 14.6 There are a variety
of DNA tumor viruses
associated with human
tumors or cancer
KC 14.6 Oncogenic viruses
directly or indirectly cause
infected host cells to
divide in an uncontrolled
manner
Virus infection carries the information
for uncontrolled cell growth
Oncogenic (DNA tumor) viruses
carry oncogenes that can disrupt
the control of cell reproduction
Unit 3-page 16
Study Set 3a
Student Test Prep
Chapter 14 – The Viruses and Virus-Like Agents
 Vocabulary [A stronger vocabulary often means a better grade]
bacteriophage (phage)
benign tumor
burst size
cancer
capsid
cell/tissue tropism
envelope
genome
host
host range
icosahedron
lysogenic cycle
lytic cycle
malignant tumor
oncogene
oncogenic virus
prophage
provirus
reverse transcriptase
spike
tail fiber
zoonotic disease (zoonosis)
 Objective Questions [Answer these in your own words]
After understanding the classroom material and textbook reading, you should be able to:
1. Explain how viruses differ from living microbes.
2. Describe the structure, shapes, and spread of viruses. [FOM 10/e: pp. 454-458]
3. Construct a list for the seven classes of animal viruses, based on nucleic acid type; give a
disease example caused by class I, IV, V, and VI. [FOM 10/e: pp. 460-462]
4. Describe the process of a productive infection. [FOM10/e: pp. 465-469]
5. Judge the significance of latent infections to disease development. [FOM 10/e: p. 469-470]
6. Explain how viruses cause disease.
7. Identify the types of antiviral drugs available to fight viral infections and explain how these
drugs work.
8. Identify how antibiotics are different from antiviral drugs.
9. List the oncogenic viruses and explain the two ways these viruses trigger tumors. [FOM 10/e:
pp. 477-478]
 Chapter Self-Test [Refer to the end of Chapter 14 in FOM 10e, pp. 487-489]
STEP A: REVIEW OF FACTS AND TERMS
 Multiple Choice: Questions 2-4, 7, 8, 10, and 11.
 Identification: 16-19.
STEP B: CONCEPT REVIEW
 26, 27, 28, 30, 31, 33, 34, and 35.
STEP C: APPLICATIONS AND PROBLEMS: None
STEP D: QUESTIONS FOR THOUGHT AND DISCUSSION: Questions 42 and 46.
Unit 3-page 17
MicroPuzzler 08
The Viruses and Virus-Like Agents
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The term for a disease spread from animals to humans
Refers to the cell/tissues infected by a virus
An uncontrolled growth or mass of body cells
A noncancerous tumor is this
A retrovirus (abbr.)
Made up of malignant cells
A segment of DNA that can cause uncontrolled cell
growth
An attachment structure on bacterial viruses
A permanent alteration in a DNA sequence
The genetic information of a virus or other organism
The attachment structures on an animal virus
The herpesviruses and smallpox virus have this type
of nucleic acid
A virus that infects bacterial cells
The viral DNA inserted into a human chromosome
Includes the viral genetic information and protein coat
The type of infection that actively produces new virus
particles
This filamentous virus has  ssRNA
The bacterial viruses and smallpox virus have this
shape
8.
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Refers to a virus that can form tumors
This viral shape has many sides
HIV contains a reverse _____ enzyme
The host _____ identifies what organisms a virus can
infect
The _____ infection is represented by a dormant
provirus
One way by which “new” viruses appear
A spreading tumor is said to be this
A shape for some viruses
A spreading tumor is said to do this
The protein coat of a virus
The lipid covering of some viruses
HIV and polio viruses have this type of genetic
material
Unit 3-page 18
FOM Chapter 17 and 18 – Eukaryotic
Microorganisms: The Fungi and the Parasites
Preview: We will examine a few eukaryotic microbes and human diseases,
specifically the fungal agent of valley fever and the protist causing malaria.
What do you think is the world’s deadliest creature and endangers
human life?
A pathogen-infected mosquito!
https://www.youtube.com/watch?v=Jt5u1lX9yZI
KEY CONCEPT 17.1
The Kingdom Fungi Includes the Molds and Yeasts
 Fungi Share a Combination of Characteristics
Unit 3-page 19
 Reproduction in Fungi Involves Spore Formation

Molds

Yeasts

Toxins and hallucinogens
From MicroFocus 17.4: “The Work of the Devil,” explain what
role fungal ergot played in early American history.
Unit 3-page 20
KEY CONCEPT 17.5
Many Fungal Pathogens Cause Lower Respiratory Tract
Diseases
■ Fungal Diseases
 Valley Fever (Coccidioidomycosis)
 Potentially severe lung infection
‒ Coccidioides immitis
Fig. 17.25


Fluconazole
Amphotericin B (IV administration for rapidly progressive disease)
Unit 3-page 21
KEY CONCEPT 18.1
Protists Exhibit Great Structural and Functional Diversity
 Most Protists are Unicellular and Nutritionally Diverse

Some protist pathogens require two different hosts
Definitive
host
Intermediate
host
Unit 3-page 22
KEY CONCEPT 18.3
Many Protistan Diseases of the Blood and the Nervous System
Can Be Life Threatening
 Malaria
 Deadly blood infection
‒ Plasmodium species
Mosquito
infected with
parasite
Gametes enter
mosquito
Parasites infect
liver
Parasites enter
red blood cells
(RBCs)

Artemisinin

Life cycle review
Unit 3-page 23
Parasites in
bloodstream
Key Concepts 17.1, 17.5, 18.1, 18.3
SUMMARY
What are some fungal and parasitic human diseases
and how are they transmitted?
KC 17.1 Molds grow by the
extension of hyphae into a
mycelium; yeasts grow as
single cells
KC 18.1 Protists are
diverse and some parasites
require two hosts
(definitive and
intermediate)
KC 17.1 Fungi reproduce
by making sexual and
asexual spores
KC 18.3 The Plasmodium
parasite causing malaria is
carried by mosquitoes
KC 17.5 Mycoses of the
lower respiratory tract
include valley fever
(coccidioidomycosis)
Valley fever and malaria
Valley fever is caused by a fungus transmitted by airborne spores
while malaria is a protist disease transmitted by mosquitoes
Unit 3-page 24
Study Set 3b
Student Test Prep
Chapters 17, 18 – Eukaryotic Microorganisms: The Fungi and Parasites
 Vocabulary [A stronger vocabulary often means a better grade]
amphotericin B
arthrospore
artemisinin
budding
carcinogen
chitin

definitive host
endospore (ref. valet fever)
fluconazole
hypha
intermediate host
mold
mycelium (pl. mycelia)
mycosis (pl. mycoses)
saprobe
spherule
spore
yeast
Objective Questions [answer these in your own words]
After understanding the classroom material and textbook reading, you should be able to:
1. Identify the characteristics of the fungi (molds and yeasts). [FOM 10/e: pp. 554-555]
2. Explain how molds and yeasts reproduce. [FOM 10/e: pp. 557-558]
3. Describe the infectious disease cycle for valley fever. [FOM 10/e: p. 577, 578]
4. Identify the characteristics of the protists and the need for two different hosts.
5. Describe the infectious cycle of Plasmodium, the causative agent of malaria. [FOM 10/e: pp.
601-603]
 Chapter Self-Test
STEP A:
STEP B:
STEP C:
STEP D:
REVIEW OF FACTS AND TERMS: None.
CONCEPT REVIEW: None.
APPLICATIONS AND PROBLEMS: None
QUESTIONS FOR THOUGHT AND DISCUSSION: None.
Unit 3-page 25
MicroPuzzler 09
Eukaryotic Microorganisms: The Fungi and Protists
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This disease affects between 300 million and 500
million people globally
The filament of a mold
A respiratory disease caused by the parasitic cycle
of a fungus (2 words)
A fungal reproductive structure
The reproduction mechanism for yeasts
A fungal toxin that may produce hallucinogenic
symptoms
A type of protist
The _____ host is where a parasite undergoes
sexual reproduction
The parasitic genus causing malaria
Released from a fungal spherule
Down
1. A single-celled fungus
2. Produced in the lung of a valley fever patient
3. A filamentous fungus
5. The agent breathed in by a human exposed to the
valley fever pathogen
8. The _____ host is where a parasite undergoes
asexual reproduction
10. The genetic material in a fungal cell
11. The vector for the malarial parasite
12. A group of fungal filaments
13. A possible fungal carcinogen
16. The carbohydrate forming the cell wall of a fungus
17. The term for a fungal disease
18. A fungus living off dead or decaying material
Unit 3-page 26
This unit has
gone viral!
UNIT EXAM
3
Unit 3-page 27