MIBO 3500 Exam 3 Scott UGA

Archaeal phylogeny

Difficult to culter & PCR

Genomes are recombinogenic

classifications are frequently under revision

Archaeal Cell Wall does not have peptidoglycan but has

pseudopeptidogylcan

The archaea Cell wall stains

gram positive or negative

the archaeal cell wall has NAG and no NAM but

N-Acetyltasamunyronic acid

T/F the archaeal cell wall is NOT susceptible to cell wall antibiotics

True

Archaeal lipids in bacteria have

L-glycerlol and ether links

Archaeal lipids in eukaryotes have

D-glycerol and ester links

Archaeal Genomes similarities to bacteria include:

Circular genome

gene size and density

presence of operons

Archaeal Genomes similarities to eukaryotes include:

presence of introns

presence of histone homologs

Parasitic Archaea: the parasitic cannot synthesize:

Lipids, amino acids, and nucleotides

Archaeal Contribution to ecosystems: AOA

AOA is Ammonia Oxidizing Archaea which oxidizes ammonia to nitrite

Archaeal Contribution to ecosystems: methanogens

releases methane from soil and digestive habits

Definition of Eukaryotes

Structure is defined by the presence of the nucleus and other membrane-enclosed organelles

Opisthokonts

Presence of unpaired flagellum at some point In the live cycle

Share several key gene insertions and deletions

EF1α

a translaiton elongaiton factor

Choanoflagellates

microbes that diverged from animals

collared cells closely resemble what kind fo cells of colonial sponges

choanocyte cells

What do sponges use to circulate water and digest food particles

choanocytes

Fungi do absorptive nutrition, what is It

secreter enzymes and then absorb the broken down nutrients

What is hyphae

multinucleate cell filaments which extend and form branches generating a mycelium

fungi cell walls contain

chitin

fungi membranes contain

ergosterol

Canidad albicans can be spread

sexual contact

Canidad albicans can involve what

skin or mucous membranes

Canidad albicans treatment

Monistat and Itraconazole mouth rinse

What does the Canidad albicans treatment do?

prevents fungal cell membrane formation. the cell contents leak out

EF1α

deals with fungi

Studied Tabacco Mosaic Disease and observed agent was NOT removed by filters

Ivanovsky

Studied the Tabacco Mosaic Disease but made the conceptual leaf that agent must be small it tases through filters

Beijerinck

Studied Food and Mouth Disease of Livestock and noticed agent NOT removed by filter

Loeffler and Frosch

Studied sarcomas in chickens. Cancer transmitted by virus

Rous

Exceptions for viruses causing harm

virus that kill pathogens or gene therapy

Virus properties

Nature of their nucleic acid (DNA or RNA)

Symmetry of their protein shell

Presence or absence of lipid membrane

nucleic acid comparison

T/F viruses have additional layers

True

T/F viruses cant exist extracpllaurly

False- they can

T/F Viruses can reproduce independent of living cells nor carry our cell division

False- they cannot

T/R Viruses have >1 molecule of DNA or RNA enclosed In their protein coat

True

What is the virion size range

10-400 nm in diameter

What do virions contain which is composed of nucleic acid and a protein coat

nucleocapsid

Structure of viruses they have what

envelopes and spikes

envelopes are:

plasma membrane components derived from their host

spikes are:

proteins used for attachment to host

What do capsids do?

Protect viral genetic material and aids in its transfer between host cells

Capsids are made of protein subunits called

protomers

Protomers aggregate to form

capsomers

Capsids can be what shapes?

helical, icosahedral or complex

Shaped like hollow tubes with protein walls. May be bent or twisted

Helical Capsids

Influenza has what shape capsid

helical

Polyherdral with 20 identical triangular faces. Structure exhibits rotational symmetry

icosahedral

Adenovirus has what shape capsid

icosahedral

Some viruses do not dit in the category of helical icosahedral so they are called

complex

Multipart structures are called

tailed viruses

Virus Genome type: DNA

double stranded DNA

Single stranded +/sense

Virus Genome type: RNA

single stranded RNA +/sense

single stranded RNA -/antisense

double stranded RNA

Virus Replication Step 1

Host recognition and attachment

Virus Replication Step 2

Genome entry

Virus Replication Step 3

Assembly of virions

Virus Replication Step 4

exit and transmission

For bacteriophages contact and attachment are mediated by

cell surface receptors

bacteriophages inject only

their genome into a cell

does the phage capsid remain inside or our and where does it attach

outside and to the cell surface

Bacteriophage quickly replicated, killing the host cell

Lytic Cycle

Bacteriophage is quiescent

Lysogenic cycle

during the lysogenic cycle what does the bacteriophage integrate into the cell chromosome as

prophage

what causes the decision between the two cycles?

environmental cues

events that threaten host cell survival trigger a what

lytic burst

Lytic Cycle Step 1:

Attachment to a bacterial host

Lytic Cycle Step 2:

phage injects DNA

Lytic Cycle Step 3:

phage destroys bacterial DNA and takes over active machinery to replicate more phage

Lytic Cycle Step 4:

phage assembles more virus

Lytic Cycle Step 5:

phage causes bacterial lysis to release phage

make enzyme that breaks down cell wall and host cell bursts to release progeny phage

lysis

lysogenic cycle step 1

daughter cell with prophage

lysogenic cycle step 2

certains facotors determine whether the lysogenic cycle will be entered

lysogenic cycle step 3

phage DNA integrates into the bacterial chromosome becoming a prophage

lysogenic cycle step 4

bacterium reproduces copying the prophase and transmitting it to daughter cells

Restriction enzymes

DNA can protect itself from destruction by what bacterial mechanism

Instead of cytosine, T4 DNA has

HMC

T/F prokaryotic cells have a more complex structure

False/ eukaryotes do

Animal viruses bind specific receptor proteins on their host cell, what do receptors determine

the viral tropism

Does animal virus entry happen by endocytosis or exocytosis

endocytosis

Where do the animal viruses enter and what do the lipids do?

Through the membrane and they surround capsid to fuse envelope

Can utilize some or all of the host replication machinery

DNA viruses

use a viral RNA-dependent RNA polymerase to generate DNA template

RNA viruses

Use a viral transcriptase to copy their genomic sequence into DNA for inception in the host chromosome

Retroviruses

All animal viruses make proteins with

host ribosomes

Where does this occur in the cell?

cytoplasm or nucleus

How does animal viruses release?

Lysis, exocytosis and budding

What are the three families of herpes

Alpha

Beta

Gamma

How is herpes distinguished?

by the type of cell they exhibit latency in

Absence of virion production where the DNA remains in host cell is called

latency

Herpes characteristics, what type of capsid

Isosahedral

T/F herpes has enveloped and spikes

True

Herpes has layers of proteins called

Tegument

T/F Herpes has dsDNA

True

HSV Type 1 and 2 has what characteristics

cold and genital sores

What is HSV 1 &2's Alpha Family Hallmark characteristic

Established latency in neuron

HSV Type 1 & 2 Cycle: Attachment

virions "surf" host cell surfaces

HSV Type 1 & 2 Cycle: Attachment

Attach to the shore Heparan Sulfate

HSV Type 1 & 2 Cycle: Entry

Virisons enter the host through fusion or endocytosis