Transcript PowerPoint
Cell Structure Review Eukaryotic Cells • • Have a nucleus Found in multi-cellular organisms & some unicellular organisms Prokaryotic Cells • • Do not have a nucleus Found in bacteria Cell Membrane • • • • Thin, flexible layer Separates the cell from its surrounding environment Controls movement of materials into and out of the cell Helps maintain the cell’s internal environment Cell Wall Cell walls, found in plant cells, are much stronger than cell membranes Rigid layer of non living material; made of cellulose Helps protect and support the cell Nucleus • • • • • Control center of the cell Manages all of the cell’s activities Largest organelle Contains the genetic material (chromatin) the cell needs to reproduce and function. Is surrounded by the nuclear envelope and also contains the nucleolus Mitochondria • • Organelles that cause the release of energy by using oxygen to break down sugars. Releases food molecules that supply energy to the cell; it is known as the powerhouse of the cell. Usually more than one in a cell Cytoplasm • • Thick, jelly-like substance contained within the cell membrane The majority of the organelles are suspended in the cytoplasm. Endoplasmic Reticulum • • • • Network of channels/tubes leading from the nuclear membrane into the cytoplasm Helps transport materials between the nucleus and the cytoplasm; acts as an assembly line Also involved in transporting proteins Two types: - Smooth E.R. = no ribosomes -Rough E.R. = contains ribosomes Lysosomes • • Sac-like structures that contain enzymes Where digestion of cell nutrients & food molecules take place Breaks down cellular waste or things that are harmful to the cell • “clean up crew” Centriole Centrioles play an important role in cell division. The centrioles are found in pairs and move towards the poles (opposite ends) of the nucleus when it is time for cell division. Chloroplast Chloroplasts are organelles found only in plant cells. Chloroplasts are the site of photosynthesis, a process in which the plant uses carbon dioxide, water and sunlight to create energy in the form of glucose for the plant. Vacuole Think of these membrane sacs as containment units. They can hold many substances from organic molecules to simple excess water. Plant cells have a central vacuole that is important in maintaining plant turgidity. “Storage units” Ribosomes • • Sites of protein manufacturing in the cell Assemble proteins that: • • • Create chemical messages to run a cell. Build cell organelles Line the membrane of the rough endoplasmic reticulum. Golgi Bodies Receive proteins and other newly formed substances from the ER, package them and distribute to other parts of the cell Labeling the cell parts Please use page 22 of your Cells and Heredity textbook to label the plant and animal cell diagrams.