Viruses & Bacteria

Chapter 17Biology 11

Presentation put together by Mandie Lynn Walls

What are Viruses

A virus is a non-cellular particle made up of genetic material and

protein that can invade living cells.

T4 Bacteriophage

Herpes Virus

Escherichia Coli Bacterium

E. coli is a bacterium. That is a crude cell, it is not a virus because viruses are protein containers with DNA

cores or RNA cores.

E. Coli and the Bacteriophage

What it looks like in real life

The Structure Of a Virus Viruses are

composed of a core of nucleic acid

The Nucleic acid core is surrounded by a protein coat called a capsid

The Nucleic core is either made up of DNA or RNA but never both

Cycle of Lytic and Lysogenic

Vaccines ►Viruses grown on chicken embryos are

attenuated vaccines►Another type of vaccine is made by

heat killing the virus

Retrovirus

Change DNA into RNA.

Example of a Retrovirus is HIV

A typical, "minimal" retrovirus consists of: • an outer envelope which

was derived from the plasma membrane of its host

• many copies of an envelope protein embedded in the lipid bilayer of its envelope

• a capsid; a protein shell containing

• two molecules of RNA and

• molecules of the enzyme reverse transcriptase

Bacteria Cell

Prokaryotes Cells that do not have a

nucleus Exist almost every where on

earth Grow in numbers so great you

can see them with the unaided eye

Are placed in either the Eubacteria or the Archebacteria Kingdoms

Make up the smaller of the two kingdoms

EubacteriaMake up the larger of the two prokaryote kingdomsGenerally are surrounded by a cell wall composed of complex carbohydrates

Cyanobacteria Photosynthetic

bacterium Bluish-greenish

color Contain membranes

that carry out the process of photosynthesis

Do not contain the same type of chloroplasts as plants do

This bluish-greenish algae can be found nearly everywhere on earth.

Can survive in extremely hot environments and even extremely cold environment

Archaebacteria Lack important

carbohydrate found in cell walls

Have different lipids in their cell membrane

Different types of ribosomes

Very different gene sequences

Archaebacteria can live in extremely harsh environments

They do not require oxygen and can live in extremely salty environments as well as extremely hot environments.

Identifying ProkaryotesCell ShapeCell WallMovement

Bacterium Shapes

Cocci~ Sphere shaped bacteria

Bacillus~ Rod shaped bacteria Spirrillium ~ Spiral shaped

bacteria Flagella~ Leg-like structures

that help to propel the bacterium.

Gram + and Gram – Bacterium Cell Walls

Cellular Walls Chemical nature of a cell wall can be

determined by Gram Staining By finding out what color the cell produces

when it is gram stained you can figure out the type of carbohydrates in the cell wall

Movement• Flagella ~ Tail like structure the

whips around to propel the bacterium

• Cillia ~ Miniature flagella surround the cell that help to “swim”

• Non motile ~ Sticky cillia like structures that keep the bacterium from moving

Flagella

http://www.md.huji.ac.il/gabi/gifs/img0102.gif

Bacteria and their energy Autotrophs Chemotrophs Heterotrophs

Autotrophs Make their own

energy Using Solar energy Eg. Cyanobacteria

Chemotrophs Make own Energy Using Chemical

energy Eg. Archaebacteria

Heterotrophs Obtain food By eating Eg. E-coli

Bacteria Respiration Obligate

Anaerobes Facultative

Anaerobes

Obligate Aerobes

Live without Oxygen Can live with or without oxygen Cannot live without oxygen.

Bacteria Reproduction Binary Fission Conjugation Spore Formation

Cellular organism copies it’s genetic information then splits into two identical daughter cells

Conjugation

A type of Bacteria Sex Two organism swap

genetic information, that contains the information such as a resistance to penicillin

Spore Formation: Endospore A type of dormant cell Exhibit no signs of life Highly resistant to

environmental stresses such as:

-High temperatures-Irradiation-Strong acids-Disinfectants

Endospores are formed by vegetative cells in response to environmental signals that indicate a limiting factor for vegetative growth, such as exhaustion of an essential nutrient.

Symbiosis Close relationship

between to species in which at least one species benefits from the other

Live together for LIFE

Parasitism

Bacteria exploit the host cell, injuring them

Eg. Mychobacterium tuberculosis

Mutualism

Symbiosis in which two of the species live together in such a way that both benefit from the relationship

Eg. E-coli

Nitrogen Fixations

Process by which nitrogen in the atmosphere is converted into a form that can be used by living things

THE END

This powerpoint was kindly donated to www.worldofteaching.com

http://www.worldofteaching.com is home to over a thousand powerpoints submitted by teachers. This is a completely free site and requires no registration. Please visit and I hope it will help in your teaching.