Exam 1: Lecture 2

Question 1

How do we develop immunity?

Answer 1

1. virus enters the body
2. virus enters cell
3. virus will do what it does and replicate inside cell
4. virus product released, APC will bind it
5. APC will displace virus to activate helper T-cell
6. T helper cells causes B cell to make antibodies, which will block virus from infecting cells and mark for destruction
7. Cytotoxic T cells id and destroy virus-infected cells
8. Long-lived T/B cells chill in body for months or years and provide immunity

Question 2

How long have microbes been around?

Answer 2

1st organism 3.5 B yrs ago (prokaryotes)
2.5 B yrs ago Eukaryotes came along (1 B yr after ^)
1 B yrs ago got multi-celled organisms (1.5 B yr after ^)
500M yrs ago development of brain (0.5 B yr after ^)
475M yrs ago life moves to land
250M yrs ago we get mammals
150K-200k yrs ago humans showed up

Question 3

If you imagine Earth began as a single day…..

Answer 3

Microbes appeared at 5 am
Dinosaurs appeared at 10pm
….. humans appeared seconds before midnight

Question 4

Archaea

Answer 4

• When 1st discovered 1977, thought to be bacteria
• exists in extreme (original thought) and less extreme places
• Humans have low lvls of archaea, don’t know importance
• Statins and Metronidazole eliminate them

Question 5

3 kingdoms

Answer 5

1. Bacteria
2. Archaea
3. Eukaryotes

Question 6

What is considered Prokaryota?

Answer 6

Bacteria

Archaea

Question 7

What is considered Eukaryota?

Answer 7

Plantae
Fungi
Animalia
Protista

Question 8

Plantae info from tree of life

Answer 8

• contain chlorophyll, necessary for photosynthesis

- cell walls made of cellulose, fixed in one place

Question 9

Fungi Info from tree of life

Answer 9

• usually motionless, absorb nutrients

- inc mushrooms, molds, and yeasts

Question 10

Animalia info from tree of life

Answer 10

• most complex organisms on earth

- divided into vertebrates and invertebrates

Question 11

Protista info from tree of life

Answer 11

• single celled organisms that have nucleus
• usually live in water
• made up of protozoa, unicellular algae, slime molds
• ex include algae, paramecium, amoeba

Question 12

Bacteria inform tree of life

Answer 12

• single celled organisms that don’t have nucleus

- more forms of bacteria than any other organism on earth

Question 13

Archaea info from tree of life

Answer 13

• bacteria with internal membranes

Question 14

6 groups of pathogens

Answer 14

1. Bacteria
2. Viruses
3. Fungi
4. Protozoa
5. Parasites
6. Prion proteins

Question 15

Order of Dec - Inc complexity

Answer 15

Viruses - Bacteria - Fungi - Parasites

Question 16

Goal of viruses

Answer 16

Viruses exist to make more viruses

Question 17

Virus structure

Answer 17

1. core of RNA or DNA enclosed in capsid, or protein coat
2. Glycoprotein envelope surrounds the capsid
3. surface proteins inserted into envelope, help attach to host cell

Question 18

How virus invades cell?

Answer 18

1. Virus enters a cell
2. Substances in the cell begin to strip the virus’s outer coat of protein
3. The nucleic acid in the center of the virus is released
4. Nucleic acid gets into the cells chemical manufacturing system
5. Cell “ignores” its own chemical needs and switches to making new viruses
6. Cell is sometimes destroyed in process. Many new viruses are released to infect other cells

Question 19

Viral Shedding

Answer 19

expulsion and release of virus progeny following successful reproduction during a host-cell infection

Question 20

Bacteriophage viruses

Answer 20

• Virus has head or “capsid” in which DNA is packed under very high pressure
• when attach to bacterium, uses pressure to inject DNA
• DNA integrates into DNA of host
• bacteriophage choose between two different life styles…dormant/latent or burst/lyse (kills bacterium)

Question 21

Bacteria info

Answer 21

1. single celled microbes
2. no nucleus or membrane bound organelles
3. Genetic info is contained in single loop of DNA
4. Some bacteria have extra circle of genetic material
   (plasmid) . it contents genes that give bacterium advantage over other bacteria. ie antibiotic resistance

Question 22

Typical fungi spore size

Answer 22

1-40 micrometers in length

Question 23

Which kingdom of microbes do fungi belong to?

Answer 23

usually saprophytes (consume dead organisms)

Question 24

Example of human fungal pathogen

Answer 24

Candida albicans

it will raise pH of surrounding environment, causing alkalization

causes a white tongue

Question 25

Prion Theory

Answer 25

1. Nerve cell makes normal PrP proteins 2. Prion version of PrP invades, forcing normal PrP to refold into a prion form 3. Unlike normal PrP, prions aren't naturally destroyed by the cell. They accumulate, eventually killing it. 4. Prions move to other cells, cycle begins again

Question 26

Mad cow and other wasting disease of the brain are caused by....

Answer 26

prions, not bacteria or viruses

Question 27

Creutzfeldt-Jakob disease causes

Answer 27

1. caused by abnormal proteins called prions that are not killed by standard methods for sterilizing surgical equipment 2. prions build up in cells, brain slowly shrinks and tissue fills with holes until it looks like a sponge

Question 28

Creutzfeldt-Jakob disease consequences

Answer 28

Those affected lose ability to think and move properly and suffer from memory loss always fatal, about 1yr from onset

Question 29

4 Developments that have taken us from a 2-generation society to a four

Answer 29

1. vaccination 2. Hygienic Medical Practice 3. Chlorination 4. Antibiotics

Question 30

Vaccine info

Answer 30

only have 34 vaccines for 400 known pathogens

Question 31

Examples of Hygienic Medical Practice

Answer 31

Handwashing Moving from antiseptic to aseptic Ruber gloves, masks, gloves

Question 32

What is water Chlorination

Answer 32

process of adding chlorine or hypochlorite to water used to kill certain bacteria and other microbes in tap water used to prevent spread of waterborne diseases such as cholera, dysentary, typhoid

Question 33

Antibiotics & Alexander Fleming

Answer 33

Discovered penicillin in 1928 shared Nobel Prize w/ Howard Florey and Ernst Boris Chain in 1945

Question 34

Koch's postulates purpose

Answer 34

criteria designed to establish a causative relationship between a microbe and a disease

Question 35

Koch's postulates

Answer 35

1. Microorganism must be found in abundance in all organisms suffering from the disease, but should not be found in healthy organisms 2. Microorganism must be isolated form a diseased organism and grown in pure culture 3. Cultured microorganism should cause disease when introduced into a healthy organism 4. Microorganism must be preisolated form the inoculated, diseased experimental host and identified as being identical to the original specific causative agent

Question 36

Becoming a healthy human is...

Answer 36

impossible without microbes important for homeostasis

Question 37

Endemic

Answer 37

constant presence (regularly found among particular people or in a certain area)

Question 38

Epidemic

Answer 38

Localized outbreak

Question 39

Pandemic

Answer 39

Widespread regional or global epidemic

Question 40

Infectivity

Answer 40

frequency with which an infection is transmitted when there is contact between the agent and a susceptible individual ex, how many of those HIV positive will develop AIDS

Question 41

Disease Index

Answer 41

Number of persons who develop the disease divided by the total number infected

Question 42

Virulence

Answer 42

number of fatal or severe cases per total number of cases

Question 43

Incidence

Answer 43

number of new cases of a disease within a specified period described as a rate in which the number of cases is on top, and number of people in population under surveillance is on bottom ex. observe how many cases in 100ppl over 3 weeks

Question 44

Prevalence

Answer 44

described as a rate to indicate total number of cases existing in a population at risk at a point in time. .