Zusammenfassung der Ressource
OCR AS Prokaryotic and Eukaryotic Cells
- Prokaryotic Cells
- Much smaller - <5um
- no membrane-bound organelles such as mitochondria, ER and chloroplasts
- surrounded by peptidoglycan cell walls
- made of murein
- ribosomes are far smaller at 20nm in diamter
- DNA is in the form of a single loop
- the general area in which plasmid DNA is found is called the nucleoid
- ATP is produced in mesosomes - infolded regions on the CSM
- some have flagella which use ATP to
rotate a disc at the base attached by a
hook to the spiral protein
- cell division by binary fission
- thick capsule layer made of polysaccharides
- Gram-negative bacteria have two membranes - the
peptidoglycan layer is thinner but outside it is a thin layer
of lipoprotein and then a second outer membrane made of
lipopolysaccharides.
- no cytoskeleton
- Eukaryotic
- Around 30nm in diameter
- Contain linear chromosomes, and the
DNA is associated with histones
- some have undulipodia which consist of a cylinder of
9 microtubules with two in the middle - use ATP
- most contain two copies of each gene - diploid
- always have a cytoskeleton
- distinct nucleus
surrounded by a nuclear
envelope. Chromatin is
found inside the nucleus
which condenses into
chromosomes during DNA
replication
- plant cells have cell walls made of cellulose, pectin and hemicellulose