Prokaryote vs. Eukaryote

• 1st division

I)Prokaryotes

A) bacteria and archea

B) characteristics

1)1-10μm

2) lack a true nucleus

a)keep DNA in nucleoids

3) no membrane bound organelles

4) many are anaerobic

a)do not require O2

5) unicellular

II) Eukaryotes

A) protists, plants, fungi, animals

B) Characteristics 1) 100-1000 μm 2) Presence of a nucleus

3) Presence of membrane bound organelles

a)ex. mitochondria to give energy

4) most are aerobic a) require O2 for

cellular respiration 5) most are multicellular

Summary chart

• Prokaryotes

– 1-10 μm

– Lack a true nucleus

– No membrane bound

organelles

– Many are anaerobic

– Unicellular

• Eukaryotes

– 100-1000 μm

– Presence of a nucleus

– Has membrane bound

organelles

– Most are aerobic

– Mostly pluricellular

III) Viruses

A)Debate over whether viruses are “alive”

1) Non-living arguments

a) Cannot live independently (require a host or remain dormant)

b) Not Cellular

2) Living arguments

a) Contain genetic material (RNA and DNA)

b) Reproduce

B)Classifying viruses

1)Classification based on capsid

a) protein coat that surrounds the genetic material of a virus

i)Spherical

ii)Cylindrical

iii)Crystalline

2) Classification based on diseases they cause

a)Viruses that affect humans are divided into 21 groups based on the differences in their genome and replication methods

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C) how viruses replicate (no cellular division)

1) the lytic cycle a)kills host cell

b)process – Virus binds to host (attachment)

– Injects the genetic material into the host cell (entry)

– The host replicates the viral genetic material (replication)

– New viral particles are assembled (assembly)

– The host cell breaks (lysis) and releases new viral particles (release)

The Lytic Cycle

• 1. Attachment

• 2. Entry

• 3. Replication

• 4. Assembly

• 5.a) Lysis

b) Release

2) the lysogenic cycle

a)As the viral RNA becomes part of the cells chromosomes, the onset of disease can be postponed until the virus goes into its lytic cycle

b)Process

– Attachment

– Entry

– Viral DNA becomes part of the host cell’s chromosomes (provirus formation)

The Lysogenic Cycle

1. Attachment

2. Entry

3. Provirus

Formation

D) Viral disease

1) cyclical symptoms can be explained via

the replication method of a virus

a) ex. cold sores

i)appear during the lytic cycle

ii)disappear during the lysogenic replication

cycle

E) Virus working for us

1) Virus use in biotechnology

a) gene therapy

i) addition of a specific gene into the virus

ii) virus can deliver and force organism to replicate that gene

iii) “typos” corrected ex. Parkinsons

b) bacteriophages

i) viruses attack bacteria

(45 min = 200 new viruses)

c) Reovirus (Respiratory Enteric Orphan Virus)

i) kills cancer cells

-head, neck, lung, liver cancers

- few side effects

IV) Prions

A) protein

1) Do not contain RNA or DNA (not a virus)

B) becomes harmful when it changes its

molecular shape

1) cause several deadly brain diseases

a)Creutzfeld-Jakob disease

b) Mad-cow disease in bovine