Cells & Organelles
page 20
Organelles?
Golgi
• Specialized structures with
specialized functions
• Containers / Organization
• Membranes as sites for chemical
reactions
chloroplast
mitochondria
Cells have to work to live…
• What do cells have to do?
– Make proteins
• Proteins control EVERY cell function
– Make energy
• For daily life & growth
– Food & water storage
– Maintain homeostasis
– Movement
– Miscellaneous
Building Proteins
• Organelles involved:
–
–
–
–
–
Nucleus
Ribosomes
Endoplasmic Reticulum (ER)
Golgi apparatus
Vesicles
THE PROTEIN ASSEMBLY LINE
Nucleus  Ribosome  ER  Golgi apparatus  Vesicles
Nucleus
• = contains DNA – genetic information
• Known as the “control center” of the cell
• Gives the instructions for protein synthesis
Ribosomes
• = Site of protein production (where proteins
are made)
• RNA gets the code from DNA and takes it to
the ribosomes
• They look like small dots!
Making Energy
• Cells must convert incoming energy to forms
that they can use for work
• Organelles involved:
– Mitochondria
• Glucose  ATP
– Chloroplast
• Sunlight  Glucose
ATP
Mitochondria
• = where energy (ATP) is made
• Known as the “powerhouse” of the cell
• Contains folds called cristae
– If you INCREASE the surface area (# of folds),
MORE energy is made!
Chloroplast
• = where photosynthesis takes place
– Makes GLUCOSE!
• ONLY PLANT CELLS HAVE CHLOROPLAST!
– Remember  photosynthesis is the reaction
plants use to make their own food
Food & Water Storage
• Organelle involved
– Vacuole
Vacuole
• = stores waste (mostly water)
• Larger in plant cells than animal cells
– Plants need to absorb excess water
– Larger Vacuole = More water
– Smaller Vacuole = Less water
Maintain Homeostasis
• Stable internal environment
• Organelle involved:
– Plasma membrane
Plasma Membrane
• = responsible for maintaining a stable,
internal environment AKA HOMEOSTASIS
– It allows certain materials in to and out of the cell
• Known as the “gatekeeper”
– AKA :
• Semi-permeable
• Cell Membrane
• Phospholipid Bilayer
Plasma Membrane
• Made of many PHOSPHOLIPIDS
– Heads: Hydrophilic
(Water loving)
– Tails: Hydrophobic
(Water fearing)
Movement
• Organelles involved:
– Cilia
– Flagella
Cilia & Flagella
• Cilia = movement; short, hair-like structure
• Flagella = movement; long, whip-like
structure
Cell Wall
• = provides structure and support to PLANT
cells
• ONLY PLANT CELLS HAVE A CELL WALL
• Located on the outside of the plasma
membrane
Cytoplasm
• = gel-like substance throughout the cell that
holds the organelles in place