3.6 Prokaryotic cells and viruses Flashcards
What is the difference between prokaryotic cells and eukaryotic cells?
Eukaryotic cells:
1. bigger
2. contain nucleus
3. no plasmids
4. membrane-bounded organelles are present
5. ribosomes are larger
6. DNA is associated (相聯) with protein
7. no capsule
8. where present, cell walls are made mostly of cellulose
Prokaryotic cells:
1. smaller
2. no nucleus
3. contain plasmids
4. no membrane-bounded organelles
5. ribosomes are smaller
6. DNA is not associated with protein (相聯)
7. may have capsule
8. cell walls are made of murein (peptidoglycan) - a glycoprotein
Prokaryotic cells are __cellular.
Unicellular
What does a prokaryotic cell contain?
- cell surface membrane
- cell wall
- cytoplasm
- ribosomes
- single circular DNA molecule
(6. plasmid)
(7. flagellum)
(8. capsule)
What is the function of cell surface membrane?
Controls the entry and exit of substances.
In prokaryotic cells, what is cell wall made of?
Murein (peptidoglycan)
What is the function of cell wall?
Acts as a physical barrier that protects from damages.
Which type of ribosome is found in prokaryotic cells?
70S
What is the function of ribosome?
Protein synthesis
What is the function of plasmid?
Contains genes that may aid the survival of bacteria in bad condition.
What is the function of flagellum?
Helps the cell to move
What is the function of capsule?
Protects cell from other cells and helps a group of cells to stick together for further protection.
What is the function of a single circular DNA molecule?
Contains genetic materials
What does a virus contain?
- genetic material (RNA)
- enzyme (reverse transcriptase)
- attachment protein
- capsid
- lipid envelope
- matrix
Virus is __cellular.
Acellular (無細胞)
Is virus smaller or bigger than bacteria?
Smaller
