Topic 1.2: Cell Ultrastructure Flashcards
Prokaryotes
Organisms whose cells lack a nucleus
Kingdom of prokaryotes
Monera (Bacteria)
Structures of prokaryotic cells (9)
a) Cytoplasm
b) Nucleoid
c) Plasmids
d) Ribosomes
e) Cell membrane
f) Cell wall
g) Slime capsule
h) Flagella
i) Pili
Cytoplasm
Internal fluid component of the cell
Nucleoid
Region of the cytoplasm where DNA is locked
Plasmids
Autonomous circular DNA
Ribosomes
Complexes of RNA and protein that are responsible for polypeptide synthesis
Cell Membrane
Semipermeable and selective barrier surrounding the cell
Cell Wall
Rigid outer covering made of peptidoglycan that maintains shape and prevents bursting
Slime Capsule
A polysaccharide layer used for protection against dessication
Flagella
Slender projection that enable movement
Pili
Hair like extensions that enable adherence to surfaces and bacterial conjugation
Bacteria cell division
Binary fission
Binary fission process (4)
a) Circular DNA is copied
b) DNA loops attach to the membrane
c) Cell enlogates, separating the loops
d) Cytokinesis occurs to form two cells.
Eukaryotes
Organisms whose cells contain a nucleus and a compartmentalised structure.