BACTERIABACTERIA

TSW investigate and understand TSW investigate and understand the life functions of Archaebacteria the life functions of Archaebacteria

and Eubacteriaand Eubacteria

Prokaryote DiversityProkaryote Diversity

Earth’s most abundant life formsEarth’s most abundant life forms

Capable of surviving in many different environmentsCapable of surviving in many different environments

Capable of getting energy from many different Capable of getting energy from many different sourcessources

Prokaryote ReviewProkaryote Review

Mostly single-celledMostly single-celled

NO nucleus or NO nucleus or organellesorganelles

Circular chromosomesCircular chromosomes

Cell wallsCell walls

Mostly asexualMostly asexual

Anaerobic or aerobicAnaerobic or aerobic

Heterotrophic or Heterotrophic or autotrophicautotrophic

ARCHAEBACTERIAARCHAEBACTERIA

No peptidoglycan in their cell wallNo peptidoglycan in their cell wall

DNA sequences are more similar to those DNA sequences are more similar to those of Eukaryotes than Eubacteriaof Eukaryotes than Eubacteria

Live in extremely harsh environmentsLive in extremely harsh environments

EUBACTERIAEUBACTERIA

Larger of the 2 KingdomsLarger of the 2 Kingdoms

Tremendous variety…live almost anywhereTremendous variety…live almost anywhere

Cell wall of peptidoglycanCell wall of peptidoglycan

Usually contain 1 or 2 cell membranesUsually contain 1 or 2 cell membranes

Identifying BacteriaIdentifying Bacteria

ShapeShape

Cell WallCell Wall

How they moveHow they move

How they obtain energyHow they obtain energy

Bacteria are named by SHAPEBacteria are named by SHAPE

Cocci (ball-shaped)Cocci (ball-shaped) Streptococcus Streptococcus

mutansmutans

Bacillus (rod-shaped)Bacillus (rod-shaped) Clostridium Clostridium

botulinumbotulinum

Spirilli (spiral-shaped)Spirilli (spiral-shaped) Treponema Treponema

palladiumpalladium

ConjugationConjugation

Sexual (exchange Sexual (exchange of genetic material of genetic material between bacteria)between bacteria)

A hollow bridge A hollow bridge forms between two forms between two bacteria and genes bacteria and genes move from one cell move from one cell to anotherto another

Importance of Bacteria Importance of Bacteria

Producers that capture energy by Producers that capture energy by photosynthesisphotosynthesis

Decomposers- breaking down the Decomposers- breaking down the nutrients in dead matter & the atmospherenutrients in dead matter & the atmosphere

Fix nitrogen Fix nitrogen

Human uses (food, digestion, medicines)Human uses (food, digestion, medicines)

What is a virus?What is a virus?

A typical virus is A typical virus is composed of a core composed of a core of DNA or RNA of DNA or RNA surrounded by a surrounded by a protein coatprotein coat

ALL viruses enter ALL viruses enter living cells & use the living cells & use the machinery of the machinery of the infected cell to infected cell to produce more virusesproduce more viruses

Viral Structure Viral Structure

CapsidCapsid: protein : protein coat that enables a coat that enables a virus to enter a host virus to enter a host cell cell

Proteins within the Proteins within the capsid bind with capsid bind with receptors on the receptors on the surface of the host surface of the host cell & trick it into cell & trick it into allowing it insideallowing it inside

Viral Infection Viral Infection

Once the virus is Once the virus is inside the host cell, inside the host cell, 2 things can 2 things can happenhappen Lytic InfectionLytic Infection Lysogenic Lysogenic

Infection Infection

Lytic InfectionLytic Infection

The BasicsThe Basics: Virus : Virus enters a cell, enters a cell, makes copies of makes copies of itself, & causes the itself, & causes the cell to burstcell to burst

KEY POINTKEY POINT: Host : Host cell is LYSED and cell is LYSED and destroyeddestroyed

Lysogenic InfectionLysogenic Infection

The BasicsThe Basics: Virus integrates its DNA into : Virus integrates its DNA into the DNA of the host cell, & the viral the DNA of the host cell, & the viral genetic info replicates along with the host genetic info replicates along with the host cell’s DNAcell’s DNA

KEY POINTKEY POINT: Host cell makes copies of : Host cell makes copies of the virus indefinitely; the host cell is NOT the virus indefinitely; the host cell is NOT destroyed right awaydestroyed right away

Are viruses ALIVE?Are viruses ALIVE?

No if we require that living things be made No if we require that living things be made up of cells & be able to live independentlyup of cells & be able to live independently

However, have many characteristics of However, have many characteristics of living thingsliving things Regulate gene expressionRegulate gene expression Able to evolveAble to evolve