Transcript Prokaryotes vs Eukaryotes - Duncanville Middle School

Cell Structures and Organelles
Cell Theory
1) All living things are composed of cells.
2) Cells are the basic units of structure and
function in living things
3) New cells are produced only from pre
existing cells.
Prokaryotes vs Eukaryotes
Prokaryotes
Eukaryotes
Have cell membranes Have nuclei and
and cytoplasm but
membrane
bound
no nuclei and
organelles.
membrane bound
organelles.
Examples: all plants,
Examples: all bacteria
Escherichia coli(
E-coli) &
Staphylococcus
(Staph infection)
animals, and fungi.
Cytoplasm and Cytoskeleton


Cytoplasm: the semifluid material inside
the plasma membrane.
Cytoskeleton: supporting network of long,
thin protein fibers, that form a framework
for the cell.
Nucleus

Cell's managing structure.

Directs cell processes.

Contains most of the cell's DNA.

Surrounded by a double membrane called
the nuclear envelope.
Ribosomes

Site of protein synthesis.

Made up of RNA and protein.

Ribosomes are produced inside the
nucleus at the nucleolus.
Endoplasmic Reticulum


Membrane system of folded sacs that
serve as the site for protein and lipid
synthesis.
Can be smooth or rough.

Smooth: there are no ribosomes
attached; complex carbohydrates and
lipids are synthesized here.

Rough: ribosomes attached; produce
proteins that will be exported to other
cells.
Golgi Apparatus
Flattened stack of membranes that modifies,
sorts, and packages proteins into sacs
called vesicles.
These vesicles can then fuse with the
plasma membrane to release proteins to
the outside of the cell.
Vacuoles
Sac used to store food, enzymes, and other
materials needed by a cell. Some
vacuoles store waste products.
Animal cells and plant cells contain vacuoles.
Lysosomes
Vesicles that contain substances that digest
excess or worn-out organelles and food
particles.
They also digest bacteria and viruses that enter
the cell.
Why do the digestive enzymes inside a
lysosome not destroy the cell?
Centrioles
Organelles made of microtubles that function
during cell division.
They are located in the cytoplasm of animal
cells and are usually near the nucleus.
Mitochondria
Organelle that converts food particles
(mainly sugar) into usable energy.
Mitochondria have an outer membrane and a
highly folded inner membrane that provides
a large surface area for breaking the bonds
in sugar molecules.
Chloroplasts
Organelles that capture light energy and
convert it to chemical energy through
photosynthesis.
The inner membrane of chloroplasts are
small disk shaped compartments called
thylakoids. Thylakoids contain chlorophyll
that traps sunlight and gives leaves and
stems their green color.
Cell Wall
Thick, rigid mesh of fibers that surround that
outside of the plasma membrane that
protects the cell and gives it support.
Only found in plant cells.
Made of cellulose which gives it its inflexible
characteristics.
Cilia
Short projections that look like hair.
Motion of cilia is simlar to the oars of a
rowboat.
Help in the movement of substances outside
the cell.
Flagella
Longer and less numerous than cilia.
Cilia and flagella are composed of
microtubles.
Aide in movement of the cell.