Viruses, Bacteria, and Protists

How big are they?

• How many bacteria could fit on the head of a pin?

• Cells Alive - How big?

VirusesViruses are not made of cells, do not have the

ability to eat, grow or develop, or reproduce like living organisms. In fact, they are tiny, non-living particles that invade and multiply inside a living

cell or host. Scientists have considered giving them a Kingdom but because they are not alive,

they don’t fit in!

The First Cells: Prokaryotes

The Five Second Rule…

Bacteria

*If the bacterium lives in an extreme environment such as high salt, extreme temperatures or the gut of other living things, it is in Kingdom Archaebacteria (Archae “ancient” bacteria).

*If the bacterium is an everyday bacteria, such as the bacteria that make us sick or the good bacteria that help us to make cheese, it is in Kingdom Eubacteria (“true bacteria”)

What is the structure of bacteria?

Coccus Bacillus Spirillum Streptococcus

Archaebacteria in the gut of termite. The caption reads: Microbes make enzymes that break down wood into fermentable sugars.

1. How do bacteria get energy?-Photosynthesis- autotrophs capture sun’s energy-Chemosynthesis- autotrophs use energy in chemicals to make food- Respiration- heterotrophs consume food and use oxygen to make ATP energy

2. How do bacteria reproduce?- Asexual reproduction- one parent divides to form two identical offspring during binary fission- “Sexual reproduction” – bacteria exchange genetic material through a tube that connects them during conjugation.

3. How do bacteria move?- flagella: a long whip-like tail

Protists are diverse eukaryotic organisms that live in moist surroundings. They can be divided into three groups:

Animal-like Plant-like Fungus-like

How do Protists obtain energy?Animal-like – Heterotroph (engulfing)

Plant-like – Autotroph (photosynthesis using sun’s energy)

Fungus-like – Heterotroph (absorb decaying materials)

How do Protists reproduce?Animal-like: sexually (conjugation) & asexually (binary fission)

Plant-like: asexually (binary fission)

Fungus-like: sexually (sperm/egg) & asexually (spore formation)

How do Protists move?Animal-like:

PseudopodiaCilia

FlagellaParasitic – move

with host

Plant-like: FlagellaFloating

Fungus-like:Oozing byPseudopodia