1.2 Ultrastructure of cells Flashcards
What are prokaryotes?
Prokaryotes are cells without a nucleus
What domains are prokaryotes?
- Archaebacteria
- Eubacteria
Draw a prokaryote
Compare to picture on bioninja
What are the important parts of a prokaryote?
- Cell wall
- Cell membrane
- Ribosomes
- Nucleoid region
Some have:
* Slimy capsule
* Plasmid
* Pili
* Flagella
What is the function of the slimy capsule?
Keeps bacteria from drying out
What is the function of the cell wall?
Provides structural support and protects the cell
What is the function of the cell membrane?
- Holds the cell together
- Seperates cell from others
- Semi-permeable
What is the function of ribosomes?
- Synthesis of proteins
- Made up of ribosomal RNA and protein
What is the function of the nucleoid region?
It’s 1 large circular DNA molecule
What is the function of the flagella?
Helps the bacteria swim
What is the function of the plasmid?
It’s a small ring of extra DNA
What is the function of pili?
Hair-like extensions that enable adherence to surfaces
How do prokaryotes replicate?
Through binary fission
What are the steps of binary fission?
- The single chromosome is replicated
- The copies move to opposite sides of the cell
- Division of the cytoplasm
- Each of the daughter cells contain one copy of the chromosome so they are identical
What are eukaryotes?
Cells that have a nucleus