Organelle: Specialized structures inside cells that have
specific shapes and functions (form & function). Each
performs a specific process/job.
Three Sections of the Cell
• All cells take in food, rid
waste, reproduce
• 4 main sections
–1) Cytoplasm
–2) Plasma Membrane
–3) Nucleus
Cytoplasm & Cytosol
• Cytoplasm: Everything between the plasma membrane
& the nucleus that includes the cytosol and organelles.
• Cytosol: Jelly-like fluid of the cytoplasm that surrounds
organelles. They “float” within this space.
– Job: Allow chemical reactions to take place.
• Aka: Cell Membrane
• Job: Allow materials to
enter/exit
• Composition: Lipids &
proteins
• Semi-Permeable: only
specific materials may enter
and exit
– Through pores & protein
channels
• Job: Controls cell activity
– Where DNA is found
– DNA holds info to
make proteins
• Inside:
– 1) Chromatin: long
strands of DNA
– 2) Nucleolus: makes
ribosomes
• AKA: ER
• Rough ER: Tunnel system that transports ribosomes
and proteins
• Smooth ER: makes fats & breaks down toxins (no
ribosomes)
• Created by nucleolus
– Exit through nuclear pores
– Some attached to ER… some free-floating
• Transported by the rough ER
• Job: Make proteins
• AKA Golgi Body
• Job: Package and transport proteins out of the cell
• Protein Creation Process Review
1) Nucleolus makes a ribosome
2) Ribosome makes protein & travels through rough ER
3) Golgi Body packages the protein into a vesicle and
exports them (like a post office).
• Membrane-bound sacs.
• Job:
• Hold materials,
like protein,
nutrients, or
waste.
• Transports
materials into or
out of a cell.
Golgi Body in Action
Vesicle expels the proteins (blue dots)
from the cell
Golgi body is placing proteins (yellow dots) into
protective vesicles
• Powerhouse: Releases energy to the cell
• Job: Create ATP (energy molecule) in a process called cellular
respiration
• Endosymbiosis theory: Mitochondria were once free living
organisms that later became parts of modern cells
– Evidence: Own DNA, own ribosomes, make proteins, replicate
• Contain digestive
enzymes
• Functions:
–1) Break down
food
–2) Kill bacteria
–3) Autolysis:
Destroy dying cell
• Job: Stores food,
water, waste, color
pigments
• Swells & shrinks
with H2O supply
• Animal cells:
Scattered smaller
vacuoles
• Centrosomes: Located near nucleus & contain 2 centrioles.
–- Centrioles: Cylinders (tubes) found in the centrosomes
and contain microtubules.
– Job: Aids in cell division. Also forms cilia and flagella.
• Used in movement
• Cilia = Short hair-like extensions (numerous)
• Flagella = Long whip-like extension (very few)
That one magical night, sperm cells swam
with the aid of a flagella!
REview
1) Pick an organelle…any organelle. Describe its function.
2) Name 7 organelles that can be found within the
cytoplasm.
3) Describe the pathway that proteins travel from creation to
exportation.
4) Which organelle creates ATP energy for cells?
5) Which organelle creates ribosomes?
6) Which organelle fuses with the cell membrane to release
proteins?
7) Which molecule holds the information to make a protein?
8) Which organelle helps with cell division?
9) What does it mean when we say that the plasma
membrane is semi-permeable?