Zusammenfassung der Ressource
Cells - Prokaryotic
- Ultrstructure of Cells
- Electron Microscopes are
used to study cell
structure
- Many organisms still
have Prokaryotic cells,
including all bacteria
- These cells have no nucleus
- The name Prokaryotic means
'before the nucleus'
- Prokaryotic cells divide in
two by a process called
binary fission
- Functions of parts of a
Prokaryotic cells
- Cell Wall
- Forms a protective outer layer that
prevents damage from outside and
also bursting if internal pressure is
too high.
- Plasma Membrane
- Controls entry and exit of
substances, pumping some of them
in by active transport.
- Cytoplasm
- Contains enzymes that catalyse the
chemical reactions of metabolism
and contains DNA in a region called
the nucleoid.
- Pili
- Hair-like structures projecting from the cell wall, when
connected to another bacterial cell they can be used
to pull the cells together.
- Flagella
- Solid protein structures, with a corkscrew
shape, projecting from the cell wall, which
rotate to cause locomotion.
- Ribosomes
- Small granular structures than synthesise proteins by
translating messenger RNA. some proteins stay in the
cell and others are secreted.
- Nucleoid
- Region of the cytoplasm that contains naked
DNA, which is the genetic information of the
cell.