PROKARYOTES AND PROTISTS

By Devin Chong and Daniel Estess

Prokaryotes

Prokaryotes are very common on earth, in fact, combined they are 10 times more mass than that of eukaryotes.

The difference in cell walls between bacteria and plant cells is that bacteria contain peptidoglycan whereas plants contain chitin or cellulose.

Gram Stan technique classifies bacteria by cell wall composition(gram positive and gram negative)

Bacteria use a flagella and taxis to locomote

Chemotaxis bacteria respond to chemicals by changing their movement pattern, this is an example to stimulus taxis.

Binary fission is bacteria's primary method of reproduction.

Nutritional Categories of bacteria

1. Photoautotrophs – photosynthesis organic compounds from CO2

2. Chemoautotrophs – only need CO2 to oxidize inorganic compounds into organic compounds

3. Photoheterotrophs – use light energy but obtain carbon in organic form

4. Chemohetrotrophs – consume organic molecules for energy and carbon

Using subunit ribosomal RNA as a marker for evolutionary relationships, prokaryotes have been classified into domains bacteria and archaea.

Prokaryotes are included in every aspect of the biosphere they recycle chemical elements between living and non living items and they work as decomposers.

Protists are more diverse than all other eukaryotes and no longer classified within a single kingdom, they can be unicellular or multi-cellular, have two types of reproduction and many ways to obtain food.

Endosymbiosis: A process in which certain unicellular organism engulf other cells which become endosymbionts and ultimately organelles in the host cell.

Secondary Endosymbiosis: A heterotrophic eukaryote ingests another organism through the food vacuole and become a endosymbionts themselves.

Major branches of the Domain Eukarya

Branch Point

Characteristics

1. Autotroph/heterotroph & decomposers

a. They need CO2 to gather their organic materialsb. Require one organic nutrient to create their foodc. Heterotrophic breakdowns rotting food to gather organic

compounds

2. Flagella/no flagella

a. Diplomonads have multiple flagella/Parabasalids move by means of flagella

b. Ciliates use cilia to move

3. Crystal rods in flagella/ no rods

Euglenozoans have spiral or crystalline rod inside their flagella most have disk shaped mitochondrial critae

4. Symbiosis with fungi

5. Live in shallow water/ live on land

a. Foraminiforans are marine and freshwater amoebas with porous shells made of organic material

b. Gymnamoebas most are heterotrophs live in soil as well as water

6. Decomposer/Heterotrophic consumer

Slave molds aggregate into plasmodium, it extends by engulfing decomposing material