Transcript Slide 1
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