❖There are more bacteria in a person’s mouth than there are people in the world?

❖Bacteria are the most numerous organisms on earth

❖Some are harmful –can cause disease

❖Some are beneficial

Prokaryote vs. Eukaryote

Prokaryote vs. Eukaryote

Prokaryote

– DNA strand but no

real nucleus

– No membrane-bound

organelles

– Different cell coverings

than eukaryotes

Eukaryote

– True nucleus that

contains DNA

– Membrane-bound

organelles (Golgi

Apparatus, ER)

– Different cell coverings

than prokaryotes

ALL of the kingdom MONERA are

prokaryotic and unicellular (single celled)

They exist everywhere on Earth Arctic, hots

springs, bottom of the ocean, on/in the body.

Anywhere that life can exist…and a few

unexpected places too!

Bacteria are the only prokaryotes on earth, so they classified them together in 1 Kingdom, Monera.

Scientists have started to treat Archaebacteria as a separate kingdom since they are so different from other bacteria

Thus creating a new 6th Kingdom

2 Kingdoms

a) Archaebacteria b) Eubacteria

(ancient bacteria) (true bacteria)

- First discovered in extreme

environments ie. Swamps, salt lakes,

and hot springs

- 3 different phylogenetic groups

1. MethanogensHarvest energy by converting H2 and CO2 to methane

gas. Can only live in anaerobic conditions (bottoms of

swamps, intestines)

2. Extreme HalophilesSalt-loving and live in high concentrated salt

environments (Great Salt Lake). Salt is used to make

ATP

3. Thermoacidophiles

Live in extremely acidic environments that have

extremely high temperatures (Hot springs)

- Accounts for most bacteria

- These are the common bacteria and the

ones will be looking at in class

* Structure – 0.2 - 10μm

Compared to viruses, they

are gigantic!!

Spirillum - spirals

Bacillus - rods

Coccus - spherical

Shape is a 2nd way to tell bacteria apart.

Bacteria - ex. CocciPrefix according to shape

Coccus – single

Diplococcus – two stick together

Streptococcus – some stick in

long chains

Staphylococcus - some stick in

bunches

*Can be a bacillus too!

GENERAL

STRUCTURE

Cell Walls:❖ Gives shape and structure

Cell Membranes:❖ Controls what enters and leaves the cell

Bacterial DNA❖ Control the cell (DNA)—not in a nucleus

Cytoplasm❖ Liquidy portion

Flagella and Pilli❖ Aids in locomotion

D/ CELL WALL STRUCTURE

A method called Gram Staining is used to tell

bacteria apart. This method consists of two dyes.

Bacteria will take up either one stain or the other

depending on the type of cell wall that they have.

❖Bacteria may have…

a) only one thick layer of carbohydrates and proteins (gram +) – turns purple.

b) a second layer of lipids and carbohydrates (gram -) – turns red