PROKARYOTES (lesson four) Flashcards
what are prokaryotes?
A prokaryote is a simple, single-celled organism that lacks a nucleus and membrane-bound organelles.
which domains are made up of prokaryotes and what does this mean
Bacteria and Archaea are made up of prokaryotic cells.
where can prokaryotes live?
-Inside and on the surface of other organisms
-In water and soil
-Deep within the earth
-In boiling hot springs
-Various other extreme environmental conditions
negative impacts of prokaryotes
- are known for their harmful effects on humans
- there are infectious bacteria called pathogens that are responsible for many human illnesses and deaths every year
positive impacts of prokaryotes
- they are involved in nutrient cycling
- digestion of foods in our guts
-production of vitamins and have commercial uses like in the production of cheese - yogurt and antibiotics
how many groups is a domain Eubacteria and how many are important?
The Domain Eubacteria has more than 12 separate groups, with 6 that are considered particularly important
Bacteria: General Characteristics
- has a cell wall, membrane, and cytoplasm
- Contain a single looped chromosome (i.e. chromosomal DNA) in an area called the nucleoid
- Ribosomes are scattered throughout the cell
- Often have pili or flagella for movement
- Sometimes will have plasmids in their cytoplasm
- Some will also be surrounded by a protective coating
what is a plasmid?
- Plasmids are a small loop of DNA with additional genes
(These genes are not essential but may be helpful to the cell)
what does a ‘protective coating’ help prevent?
These prevent water loss, resist temperature changes, and keep out antibiotic and virus
what is a round-shaped bacteria called?
coccus
what is a rod-shaped bacteria called?
bacillus
what is a spiral-shaped bacteria called?
spirochete/spirilla
what are bacteria that are in pairs called?
Diplo
what are bacteria that are in a chain called?
strepto
what are bacteria that are in clusters called
staphilo
Domain Archaea
- little is known about archaea
-Their cell walls and membranes have a unique chemical makeup
-They also have a unique genetic code
-Most inhabit extreme environments
What are the similarities between prokaryotes and eukaryotes?
-Have DNA
-Have ribosomes
-Have cytoplasm
-Have cell membrane
What are the differences between prokaryotes and eukaryotes?
- eukaryotes are bigger, more complex, and have a nucleus
- prokaryotes have cell walls
are bacteria autotrophs or heterotrophs?
bacteria are both
What process do bacteria go through in order to multiply?
Binary fissions
Similarities between bacteria and archaea?
-Unicellular
-Prokaryotic
-Genetic material
-Ribosomes
-Cytoplasm
-Can be autotrophs and heterotrophs
-Binary fissions
Differences between bacteria and archaea?
- Membrane structure. Archaea have a monolid layer instead of a build layer
- Has a unique cell wall. They do not have peptidoglycan
-Some differences in genetics (i.e entry points)
