1.2 Ultrastructure of cells - Prokaryotic cells Flashcards
1
Q
What are the 5 kingdoms of life?
A
- prokaryotes
- protoktista/protozoa
- plantae
- animalia
- fungi
2
Q
what is an organelle
A
discrete structure within a cell that has a specific function
3
Q
prokaryotes general info
A
- naked DNA spread in cytoplasm (in nucleiod)
- DNA strand not associated w/ proteins
- NO nucleus
- smaller than eukaryotic cell
- lack membrane bound organelles/compartments
4
Q
what is e. coli?
what does it do?
A
a bacterium that is part of the normal microflora of the human gut
- produces vitamin k
- prevents establishment of pathogenic bacteria in intestine
- can reproduce too much and cause problems
- can come from bad food
5
Q
division of prokaryotic cells
A
- divide with binary fission
- asexual reproduction
- divide into 2 genetically identical daughter cells
- first elongation, then division
6
Q
9 parts of a prokaryotic cell structure
A
- capsule (found in some)
- cell wall
- cell membrane
- plasmid
- pili
- flagella
- ribosome
- cytoplasm
7
Q
capsule
A
- thick mucous envelope
- made of polypeptides & carbohydrates
- surrounds cell wall of SOME bacteria
- extra protection vs ingestion by phagocytes, drying out
8
Q
cell wall
A
- maintains shape of cell
- made of PEPTIDOGLYCAN
9
Q
pili
A
- protein filaments on cell wall
- used for cell to cell adhesion
- allow bacterial aggregations
- hold bacterial cells attached during conjugation (sexual repro)
10
Q
flagella
A
allows movement
11
Q
plasma membrane
A
- controls passage of materials
- made of PHOSPHOLIPIDS
12
Q
cytoplasm
A
- has enzymes that catalyse metabolic reactions
- has loose DNA in nucleoid
13
Q
ribosomes
A
- made of 2 subunits
- synthesises proteins
- smaller than the eukaryotic ones
14
Q
nucleoid
A
- region of cytoplasm w/ naked DNA
- has genetic info (directs activities of cell)
15
Q
plasmid
A
- small rings of DNA that serve as additional chromosomes
- replicate independently
- genetic engineering as means of inserting genes
