ch 7: prokaryotes and eukaryotes Flashcards
what features do ALL CELLS have?
cell membranes, cytoplasm, genome of DNA, and ribosomes
cell membrane
phospholipid bilayer, surrounds the fluids and other structures that make up the “insides of a cell”
cytoplasm
the insides, which consists of a liquid, water based cytosol containing dissolved molecules
ribosomes
RNA molecules that make proteins using information copied from DNA
features of prokaryotes
- rigid cell wall
- additional outer plasma membrane
- slimy capsule of polysaccharide
- flagellum
- fimbriae
flagellum
whip-like protein complex that allows prokaryotes to move
fimbriae
hair-like projections that allow prokaryotes to stick to surfaces
can prokaryotes exist as free-living single cells?
yes and also in aggregates (chains, clusters or biofilms)
how did eukaryotic cells evolve?
from a prokaryotic ancestor
why do eukaryotes differ from prokaryotes?
the cell membrane from prokaryotes migrated and surrounded different parts of cytoplasm to create organelles
endosymbiosis
mutually beneficial relationship between two organisms where one lives inside the body of another
- some single-celled organisms were engulfed and kept
what was the first proto-organelle to form from cell membrane of prokaryote?
endoplasmic reticulum which later enclosed the DNA to form nucleus
possible paths of evolution to eukaryotic cells
- inside out
- outside in
are prokaryotes or eukaryotes bigger?
eukaryotes (10 to 100um) compared to prokaryotes (1 to 10um)
how does DNA form differ in eukaryotes and prokaryotes?
eukaryotes: DNA in linear chromosomal form
prokaryotes: circular chromosomal form in nucleoid
what are prokaryotes?
archaea and bacteria
- most common cell type
do prokaryotes have membrane-bound compartments?
no, eukaryotes do and they are called organelles
eukaryote types
plant and animal cells
what do plant cells have that animal cells do not?
- cell wall surrounding plasma membrane
- chloroplasts
- large central vacuole
where are ribosomes in prokaryotes?
free floating in cytoplasm
where are ribosomes in eukaryotes?
free floating in cytoplasm or attached to rough ER
functions of cytoskeleton
- supports and maintains cell shapes
- railroad track for organelle and vesicle movement
- anchors the cell and organelles
- make-up cilia and flagella
structural features of cytoskeleton
long spindle-like protein fibers
what do proteins in plasma membranes anchor to?
cytoskeleton and extra cellular matrix