Cells & Organellespage 20

Organelles?

• Specialized structures with specialized functions

• Containers / Organization• Membranes as sites for chemical

reactions

mitochondria

chloroplast

Golgi

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 LINENucleus 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