Organelles Defined. Class Copy CELL STUDY NOTES Class Copy

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1 Cell Theory States: 1. All living things are composed of cells 2. Cells are the basic units of structure and function in living things 3. New cells are produced from existing cells Organelles Defined Golgi Cell (Plasma) Membrane Cell (Plasma) Membrane Cell (Plasma) Membrane Proteins are absorbed, modified, packaged and distributed to their destination in this organelle. This selectively permeable structure is composed of phospholipids embedded with proteins. selectively permeable ; semi-permeable, allows materials to enter and exit the cell; all cells have one of these Outermost part of cell that does not have a cell wall. Can easily be confused with the cell wall (See Cell Wall). Cell Wall Composed of cellulose, this gives plant cells stability. Cell Wall supports structure (plants, bacteria & fungi have cell walls) provides protection and support for the cell

2 Cell Wall Centrioles If the cell is labeled plant, bacteria or fungi, look for a cell wall on the outside of the cell membrane. Sometimes drawn as mesh or fiber-like material. These small microtubules are involved in animal cell division. Centrioles Centrioles Used in animal cell division only Always shown as a pair, next to the nucleus, and only in animal cells. Looks like little, cylindrical stacks of tubes. Sometimes shown in cross section as a swirl of lines or commas. This organelle is green due to the presence of chlorophyll and is the site of photosynthesis. food production Usually has oval to round shape. Membranes inside are usually stacked like papers. where photosynthesis takes place Chromosomes Structures within the nucleus that are composed of DNA. Called chromatin in a non-dividing cell. Chromosomes Chromosomes Cytoplasm genetic information Usually in the form of chromatin, a spaghetti like group of DNA strands. Occasionally the chromosomes are shown as X-shaped structures within the nucleus. Everything between the cell membrane and the nucleus. Contains all organelles and cytosol (solution in the cell).

3 Cytoplasm jelly-like substance where chemical reactions take place, the portion of the cell outside the nucleus Cytoplasm Cytoskeleton Usually labeled with a line pointing to the inside of a cell but not to any particular structure. The "skeleton" and "muscles" of the cell, this structure is made of microtubules that also form cilia, flagella and centrioles. Cytoskeleton internal support, cilia and flagella Golgi apparatus Golgi apparatus protein package and distribution center sorts, packages, and ships proteins and other materials Shown further away from the nucleus than the ER, looks like stacks of pita bread with small dots (vesicles) to each side. Large, Central Vacuole water and solute compartment in plant cells Lysosome This specialized vesicle contains digestive enzymes and is the site of hydrolysis in animal cells Lysosome Lysosome Mitochondria digestion/hydrolysis uses enzymes to break down old organelles for reuse Found in animal cells. They are easily confused with vesicles but sometimes with various internal features such as small food particles. The "Powerhouse" of the cell, this organelle is the site of cellular respiration and production of ATP. Mitochondria power house: converts food energy into energy the cell can use (ATP); the powerhouse of the cell

4 Mitochondria Nuclear Membrane (Envelope) Usually peanut or jelly bean shaped with a squiggle or worm shape within. May be confused with the chloroplast in a plant cell. This membrane holds the chromosomes within the nucleus. Nuclear Membrane (Envelope) Nuclear Membrane (Envelope) Nucleolus protects chromosomes allows materials to move into and out of the nucleus The membrane around the nucleus. Usually with obvious nuclear pores or holes. Can be confused with the nucleus so look for labels that might apply to each part. Dark sections of DNA and proteins in the nucleus which are the site of ribosome synthesis. Nucleolus site of ribosome synthesis where ribosomes are made Nucleolus Dark area(s) (nucleoli) within the nucleus. It is part of the DNA and will be mixed in with the chromatin. Nucleus This, the largest object in a eukaryotic cell, holds the cell's genetic information. Nucleus control center contains the DNA of the cell, controls cell functions Nucleus RER Rough Endoplasmic RER Rough Endoplasmic Usually easy to locate, the largest structure in the cell. Normally oval or round in shape. This extensive network of membranes is studded with ribosomes and functions as a surface for protein synthesis and transport of materials. surface for protein synthesis and transport

5 RER Rough Endoplasmic Ribosomes Ribosomes Membranes normally located just outside the nucleus and dotted with obvious ribosomes. Although not membrane bound, this organelle is the site of protein synthesis. Internal transportation of proteins and contains ribosomes site of protein synthesis manufactures or makes proteins ribosomes Represented as small, free floating dots in the cytoplasm or attached to the outside of the rough ER. SER Smooth Endoplasmic This set of smooth membranes functions to synthesize lipids and detoxify drugs and toxins. SER Smooth Endoplasmic detoxification/ lipid synthesis used to detoxify the cell and synthesize lipids SER Smooth Endoplasmic Similar to rough ER, usually further away from the nucleus than the ER, never with dots. Vacuole vacuole vacuole This organelle is very large in plant cells and contains food, enzymes, minerals, wastes and water. Easily identified as a large, central, fluid filled space in a plant cell. Food vacuoles are much smaller. Contractile vacuoles are star-shaped. Several small ones can be found in animal cells. Only one very large vacuole is found in a plant cell. vacuole sac-like structures in the cell that store materials such as water, food and waste vesicle Small, fluid filled organelles in animal cells. Easily confused with the lysosome in an animal cell.

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7 Prokaryote Cell Does not have a nucleus Single circular DNA in nucleoid region Ribosomes smaller and less complex Contain no membrane bound organelles Cells are smaller Reproduction is always asexual Cell division is by binary fission No cytoskeleton Usually unicellular and some have cell walls with peptidoglycan May not need oxygen to exist Bacteria, Archaebacteria Eukaryote Cell Have nucleus Linear DNA within membrane bound nucleus Ribosomes bigger and more complex Cytoplasm filled with organelles Cells are bigger Both asexual and sexual reproduction Cell division is by mitosis or meiosis Always has cytoskeleton Often multicellular, some have cell walls Usually need oxygen to exist Plants, Animals, Protists, Fungi