Eukaryotic Cell Organelles

Transcription

1 Name Class Date Eukaryotic Cell Organelles Cell Membrane Outermost living layer Flexible and elastic barrier that surrounds the cell Made of a lipid bilayer (double layer) Separates and encloses the cell from its environment Protection and support Communication Controls what goes in and out of the cell (AKA gate of the cell) selectively permeable or semi-permeable. Passive transport vs. active transport Peripheral vs. Integral proteins Cytoplasm Jellylike, clear, aqueous (80%) substance that fills the cell. It contains all organelles, H 2O, dissolved gasses, (O2 and CO2), salts, organic molecules, enzymes, and cytoskeleton. Responsible for the cell s internal transport (cytoplasmic streaming) See pages 10, 11, and 27 of your textbook. Ribosomes Small, spherical, non-membrane-bounded, structures made primary of nucleic acid RNA and protein Most numerous organelles Can be found floating in the cytoplasm or embedded in the RER. They are made in the nucleolus. Site of protein synthesis (protein factories of the cell) It gets its instructions from the DNA of the cell. Nucleolus Small, dark area located inside the nucleus Synthesis (or creation) of ribosomes. Cilia & Flagella Cilia (Lat. cilium, eyelash, hair) and flagella (Lat. flagello, whip) are hair like projections that can move either in an undulating fashion, like a whip, or stiffly, like an oar. They provide cells with locomotion (food and predators). Examples: A paramecium has cilia, while a sperm cell has a flagellum.

2 Microvilli 1 Centrosome

3 Nucleus Large, oval structure that controls and regulates cell activities Double membrane; nuclear envelope. Nuclear pores allow movement of molecules in an out of nucleus through the cell membrane. Directs the synthesis of proteins that regulate most of the chemical processes that take place inside the cell. Transmit hereditary information contained in NDA DNA never leaves the nucleus The nucleus directs cell s reproduction Mitochondria Mitos «thread» Chondrion «grain» Large, rod-shaped organelles, with two membranes; one of which is folded to form cristae. Mitochondria contain their own circular mtdna and ribosomes. They can grow, divide and give rise to others independently of the cell. Known as the powerhouse of the cell. Food molecules are broken down in the presence of oxygen to release energy. Energy is stored in ATP. This conversion of food energy to ATP is known as cellular respiration. Lysosomes Discovered by Rene de Duve in Small, round structure (vesicle) produced in the Golgi complex that are found floating in the cytoplasm of all eukaryotic cells Common in animals, fungi, and protists Rare in plants Contain potent hydrolytic digestive and destructive enzymes Known as the clean up crew or recycling center Break down large food molecules Digest old, worn-out organelles and debris Digest old or injured cells; selfdestruct mechanism Protect the cell against invaders (self-defense mechanism) Cytoskeleton Protein fibers that extend through the cytoplasm of eukaryotic cells. They act as framework to give shape to the cell and enable structure within it, or the entire cells to move. Vacuole Large, round, water-filled sac that has a single membrane around it and it floats in the cytoplasm (vesicle). Lager in plant cell; known as the storage tank of the cell (water, enzymes, nutrients, water). Keeps plant cells firm and supports its shape; plants may wilt when the central vacuole loses water

4 Plant Cell

5 Endosplasmic Reticulum (ER) Network of clear membranes and sacs that forms and intracellular highway that spreads from the nucleus through the cytoplasm. SER lacks ribosomes RER has ribosomes on its outer surface make protein. Synthesizes and transport proteins, steroids, lipids and other materials throughout the cell needed by the cell or for export. The amount of ER depends on the cell s job. Golgi Apparatus Golgi Body Italian anatomist and microscopist Camillo Golgi in 1898 Collects, processes, modifies packages and secretes protein for export Golgi Complex Flattened membranes or sacs that Golgi works closely with RER Chloroplast Contain pigments that capture solar energy mainly chlorophyll. Found in both plant and algae cells Larger than mitochondria Provide energy for the cell Double membrane Own circular DNA Own ribosomes Reproduces by itself Takes solar energy to convert into chemical energy for storage, e.g., glucose and ATP. Site of photosynthesis Cell Wall Strong, rigid, nonliving layer found outside the cell membrane of archaea, bacteria, fungi, plants, and algae. Made of cellulose (50% of wood) It has openings called plasmodesmata It protects and support the cell Chromosomes (Chroma, «color», soma, «body») Thick, rod-shape, objects made of chromatin and protein Found in floating in the nucleoplasm Clearly visible only when the cell is dividing Made of nucleic acids store information needed for protein synthesis Direct cell activities, including growth and reproduction Pass on traits of the cell to the new daughter cells

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