Lecture 35 - Microbes And Viruses

Front 1

what did people assume about bacteria?

Back 1

bacteria always thrives in warm, rich media (not true!)

Front 2

Experiement protocol for bacteria dna:

Back 2

1. collect sample, lyse cells, purify dna
2. PCR
3. insert genes into individual plasmids
4. add plasmid to cells, let cells grow
5. purfy genes from all the cells
6. sequence the genes, compare to the known sequence

Front 3

what is the most abundant bacteria in the planet?

Back 3

plankton

Front 4

what is the number one factor of decrease in mortality rate?

Back 4

sanitation, munical improvement, not antibiotics

Front 5

how to antobiotics work?

Back 5

antibiotic poison bacterial enzymes involved in the cell wall synthesis* unique prokaryotic metabolic pathway

Front 6

what 2 things contribute to antibiotic resistance?

Back 6

1. antibiotics are 99% effective, but the 1% mutated bacteria that survives and copies
2. superbugs exist and they are immune to everything

Front 7

what are three molecular mechanisms that are responsible for the spread of antibiotic resistant strains of bacteria?

Back 7

1 mutation
2 lateral gene transfer
3 meiotic recombination

Front 8

what is gram staining?

Back 8

a generic way to differentiate between two large groups of cells. this is the first step in identifying bacteria

Front 9

does gram positive or gram negative retain more stain?

Back 9

gram positive

Front 10

what do gram positive bacteria have a lot of?

Back 10

peptidoglycan

Front 11

what do the gram negative cells have?

Back 11

little peptidoglycan and an outer membrane

Front 12

phototrophs (cyanobacteria)

Back 12

light energy to produce ATP by photophosphorylation and fix CO2 by the Calvin cycle. phototrophs work like plants

Front 13

organotrophs

Back 13

oxidize organic molecules with high potential energy to produce ATP by cellular respiration or fermentationi

Front 14

Lithotrophs

Back 14

oxidize inorganic molecules much as ammonia or methane to produce ATP by cell. respiration. some fix CO2 others use methanol or CO as a carbon source

Front 15

what is the purpose of nitrogen fixation

Back 15

nitrogen is used to synthesize proteins and nuclei

Front 16

what IS nitrogen fixation?

Back 16

the reduction of molecular nitrogen to form amino groups, ammonia and nitrates used by euks. bacteria/proks are what actually fix the nitrogen

Front 17

cannibalism

Back 17

the evolutionary origin of eukaryotic organelles

Front 18

general endosymbiosis theory

Back 18

phaocyte engolfs its prey and host cells gets abundance of ATP

Front 19

origination of mitochondria

Back 19

phagocytosis of bacteria with aerobic cellular respiration (duh, think of its function now)

Front 20

chloroplasts

Back 20

rose from phagocytosis of cyanobacteria(photosynthesis bacteria, again think of the function today)

Front 21

what are viruses also known as?

Back 21

particles, agents, OBLIGATE PARASITES

Front 22

viruses have _

Back 22

genome (DNA or RNA) and they evolve

Front 23

what does a virus do?

Back 23

enter host cell and take over its biosynthetic machinaery

Front 24

caspid

Back 24

shell of proteins

Front 25

in addition to caspid, some viruses have_

Back 25

membrane like nevelope (stolen from host cell)

Front 26

does HIV have the extra membrane?

Back 26

yes

Front 27

LYTIC REPLICATION

Back 27

*steps to create a new generation of viruses
1. introduce gene into DNA
2. make mRNA
3. transcirbe mRNA to make viral proteins
4. proteins are processed ti make new particles
5. particles exit to exterior
6. death of host cell

Front 28

LYSOGENIC REPLICATION

Back 28

*results in virus genes being incorporated into the host genome
1. virus enters host
2. integrates into genome
3. copies into chromosome
4. cell divided with the additional gene

Front 29

what type of cells do HIV particle target?

Back 29

Human T-cells of the immune system

Front 30

what are viruses also known as?

Back 30

particles, agents, OBLIGATE PARASITES

Front 31

viruses have _

Back 31

genome (DNA or RNA) and they evolve

Front 32

what is the mechanism for a virus to en

Back 32

come back..

Front 33

what does a virus do?

Back 33

enter host cell and take over its biosynthetic machinaery

Front 34

caspid

Back 34

shell of proteins

Front 35

in addition to caspid, some viruses have_

Back 35

membrane like nevelope (stolen from host cell)

Front 36

does HIV have the extra membrane?

Back 36

yes

Front 37

LYTIC REPLICATION

Back 37

*steps to create a new generation of viruses
1. introduce gene into DNA
2. make mRNA
3. transcirbe mRNA to make viral proteins
4. proteins are processed ti make new particles
5. particles exit to exterior
6. death of host cell

Front 38

LYSOGENIC REPLICATION

Back 38

*results in virus genes being incorporated into the host genome
1. virus enters host
2. integrates into genome
3. copies into chromosome
4. cell divided with the additional gene

Front 39

what type of cells do HIV particle target?

Back 39

Human T-cells of the immune system

Front 40

What is the "doorknob" protein that HIV use to enter host cells?

Back 40

CD4

Front 41

Explain the experiment procedure how scientists figured out CD4 is the doorknob protein

Back 41

1. identical t-cells in culture
2. add different anti-bodies for different proteins (the correct anti-body will block the correct protein and those cells will be uninfected)
3. add constant number of HIV
4. observe which culture of cells survive

Front 42

How does a virus bind to a host cell?

Back 42

1. glycoprotein on HIV envelope binds to the CD4 protein on the host cell membrane
2. co-receptor on the host cell membrane must bind as well

Front 43

What are the specific host cell co-receptors?

Back 43

CCR5 on lymphocytes
CXCR4 on macrophages

Front 44

what is a retrovirus?

Back 44

ssRNA viruses that produce reverse transcriptase

Front 45

review: what is reverse transcriptase?

Back 45

a DNA polymerase that makes cDNA from an RNA template

Front 46

3 steps in production of *envelope proteins

Back 46

1. viral mRNAs translated by ribosomes and attached to rough ER
2. protein travels through the golgi apparatus and gain carbohydrates
3. resulting glycoproteins leave through the membrane

Front 47

3 steps in *core protein

Back 47

1. viral mRNA is translated by ribosomes in the cytoplasm
2. protease cuts the polypeptides into functional proteins
3. the resulting pieces curl/roll up and are assembled near plasma membrane

Front 48

lysis

Back 48

when viruses bud or burst out of a cell

Front 49

what "buds"?

Back 49

enveloped viruses

Front 50

What is the "doorknob" protein that HIV use to enter host cells?

Back 50

CD4

Front 51

Explain the experiment procedure how scientists figured out CD4 is the doorknob protein

Back 51

1. identical t-cells in culture
2. add different anti-bodies for different proteins (the correct anti-body will block the correct protein and those cells will be uninfected)
3. add constant number of HIV
4. observe which culture of cells survive

Front 52

How does a virus bind to a host cell?

Back 52

1. glycoprotein on HIV envelope binds to the CD4 protein on the host cell membrane
2. co-receptor on the host cell membrane must bind as well

Front 53

What are the specific host cell co-receptors?

Back 53

CCR5 on lymphocytes
CXCR4 on macrophages

Front 54

what is a retrovirus?

Back 54

ssRNA viruses that produce reverse transcriptase

Front 55

review: what is reverse transcriptase?

Back 55

a DNA polymerase that makes cDNA from an RNA template

Front 56

3 steps in production of *envelope proteins

Back 56

1. viral mRNAs translated by ribosomes and attached to rough ER
2. protein travels through the golgi apparatus and gain carbohydrates
3. resulting glycoproteins leave through the membrane

Front 57

3 steps in *core protein

Back 57

1. viral mRNA is translated by ribosomes in the cytoplasm
2. protease cuts the polypeptides into functional proteins
3. the resulting pieces curl/roll up and are assembled near plasma membrane

Front 58

lysis

Back 58

when viruses bud or burst out of a cell

Front 59

what "buds"?

Back 59

enveloped viruses

Front 60

what "bursts" out of a host cell?

Back 60

non-enveloped viruses

Front 61

what are two targets in an anti HIV therapy cocktail?

Back 61

inhibitors against 1. HIV reverse transcriptase and 2. HIV protease

Front 62

5 steps how vaccination works

Back 62

1. viral antigens are introduced into the body
2. antigens bind to receptors on certain immune system cells
3. the attachment of the two stimulate other immune system cells to produce antibodies to the virus
4. later the antibodies will cover the virus if it appears again
5. other immune system cells destroy the virus with the antibodies all around it