The Cell’s Machinery

Main Idea Eukaryotic cells have specialized internal structures called organelles that are surrounded by a membrane (membrane bound) Organelles have specific jobs that Keep cells alive Allow cell to do its special job

Cell Membrane/ Plasma membrane Semipermeable outer covering of cell Selectively permeable Provides support and protection Allows for different internal environment

Made of double layer of phospholipid molecules Phosphate molecule head Hydrophilic – water loving Fatty acid molecule “tails” Hydrophobic –water avoiding

Cytoplasm Space between nucleus and cell membrane Filled with fluid (cytosol) and organelles

Cytoplasm Space between nucleus and cell membrane Filled with fluid (cytosol) and organelles

Cytoskeleton Cell’s framework Made of protein fibers: 1. Microtubules 2. Intermediate filaments 3. Microfilaments

Cytoskeleton Provides shape and strength Helps cells move and divide

Nucleus Found only in Eukaryotic cells Location of DNA Surrounded by nuclear envelope/membrane

Nuclear envelope/membrane Surrounds nucleus Contains small holes called nuclear pores Pores let molecules move between cytoplasm and nucleus

Nucleolus Located inside nucleus Manufactures ribosomes

Ribosomes Site of protein synthesis Link amino acids together to form proteins

Ribosomes Found in 2 locations: 1. Attached to ER “Rough ER” 2. Free floating in cytoplasm

Endoplasmic Reticulum “ER” Network of folded membranes where chemical rxns occur

Endoplasmic Reticulum Rough ER – ribosomes attached Smooth ER – no ribosomes attached

Golgi Apparatus / Golgi Bodies Stack of membrane–enclosed spaces Put “finishing touches” on newly made proteins Package proteins inside vesicles for shipment

Vesicles Small membrane-enclosed sac Stores and transports substances

Types of Vesicles Vacuoles – contain water Lysosomes – store digestive enzymes Transport – carry molecules within cell Secretory – carry molecules outside cell

Vacuoles Stores Food Water Waste

Lysosomes Contain digestive enzymes used to destroy Viruses and Bacteria Worn out cell parts Lysosome ACTION!

Vesicle movement Endocytosis (move into the cell) and Exocytosis (movement out of cell)

Cilia Short hair-like protein fiber on outside of cell membrane Move the cell Move things past cell Gather food The protist Vorticelli feeding with cilia Movement of substances like mucus Cilia moving mucus

Flagella Long whip-like tail fiber Used for movement Ex. Sperm tail A Sperm’s Journey

Comparison of Cilia and Flagella

Mitochondria “Powerhouse of the Cell” Site of Cell Respiration rxns - energy stored in food molecules is converted into E the body can use Made of two membranes – inner and outer Inner membrane has many folds - increases surface area

How Mighty Mitochondria Works

Chloroplast Found in plant cells Site of photosynthesis rxns. Contain the green pigment chlorophyll

Centrosomes and Centrioles Centrosomes make microtubules In animal cells, centrosomes contain centriole fibers Form spindle fibers used in cell division