Cell Structure and Function.pdf

Cell Structure and Function Rice University. (2018). Biology for AP Courses. OpenStax. Rice University. Urry, Lisa; Cain, Michael; Wasserman, Steven; Minorsky, Peter; Orr, Rebecca; & Campbell, Neil. (2021). Campbell Biology. 12th Ed. Pearson. Cells Cells are the basic unit...

Cell Structure and Function Rice University. (2018). Biology for AP Courses. OpenStax. Rice University. Urry, Lisa; Cain, Michael; Wasserman, Steven; Minorsky, Peter; Orr, Rebecca; & Campbell, Neil. (2021). Campbell Biology. 12th Ed. Pearson. Cells Cells are the basic units of life. They are self-contained, functional structures that make up living organisms. Organisms can consist of only one cell. They are called unicellular. Other organisms are composed of multiple cells. They are called multicellular. Cells It may be useful to think of cells as other objects to better understand their function: cells build up tissues, which build up organs, similar to how Lego blocks build bigger structures functionally, they can also be compared with important locations in a city Field Trip! City border City Hall Public library Field Trip! Manufacturing and Power plant industrial centers Marketplaces and malls Field Trip! Landfills Delivery services Infrastructure Membrane and Cytoplasm All cells are bound by a protective covering, a double layer composed of phospholipids called the cell membrane. The cell membrane separates the cell from the extracellular space. Within the cell is a gelatin-like substance called cytoplasm, also called the cytosol, where all other cell parts, called organelles, are found. Nucleus The nucleus is a large, often centrally, located organelle. It is covered by the nuclear membrane. The nucleus regulates cellular function and activity, and stores genetic information. A darker area within the nucleus, called the nucleolus, creates ribosomes, an organelle that assembles proteins. Metabolic Organelles The mitochondrion is a sausage-shaped organelle where cellular respiration takes place, breaking down glucose to provide the energy needs of a cell. The plastid is an organelle in photosynthetic organisms. It allows the cell to use energy from sunlight to synthesize glucose. Both these organelles are membrane- bound. Endoplasmic Reticulum The endoplasmic reticulum (ER), also called the endomembrane system, is a series of membranes near the nucleus. The rough ER contains ribosomes, tiny organelles that manufacture proteins. The smooth ER has no ribosomes and synthesizes other cellular products. Golgi Apparatus The Golgi apparatus, or Golgi body, is a series of membranes farther out from the nucleus than the ER. It receives cellular products from the ER, stores and processes them, and distributes them to other sites in the cell via temporary membrane-bound containment units called vesicles. Lysosome Lysosomes are specialized vesicles in animal cells. Recall that vesicles are membrane- bound spaces that transport substances throughout the cell. Lysosomes contain enzymes that dissolve worn-out or damaged cell parts and invasive organisms like bacteria. Cytoskeleton and Locomotory Organelles The cytoskeleton is a series of protein units that are assembled, torn down, and reassembled to hold and alter cell shape. The cytoskeleton supports the formation of locomotory organelles such as cilia, pseudopodia, and flagella. Learning prompt Which organelles or cell parts have a similar function to the city locations previously mentioned? city border government and educational sector power sector manufacturing and industrial centers commercial centers delivery services cleanup, recycling, and disposal infrastructure and transportation Centrioles Centrioles are paired organelles in animal cells. They are also collectively called the centrosome. They are found near the nucleus and help maintain cell shape and organization during cell division. Central Vacuole Plant cells contain a large central vacuole. This organelle serves in storage and pressure control. Since plant cells do not contain lysosomes, they also help with cell cleanup. Cell Wall Some cells contain an additional protective rigid outer covering, the cell wall. It is composed of different substances depending on the organism: plants and algae - cellulose fungi - chitin bacteria - peptidoglycan archaea - pseudopeptidoglycan and other substances Features unique to plant cells Features unique to animal cells include: include: cell walls lysosomes plastids such as chloroplasts centrioles central vacuoles NO cell walls NO lysosomes NO central vacuoles NO centrioles NO plastids Cellular features inform the classification schemes biologists use. While animals, plants, fungi, and protists belong to different kingdoms, their cellular similarities allow them to be grouped into one domain. The cell features discussed thus far all refer to eukaryotic (“true nucleus”) cells. Eukaryotic cells are larger and more complex. They contain nuclei and membrane-bound organelles. Animals, plants, fungi, and protists all have eukaryotic cells. Bacteria and archaea have prokaryotic (“before the nucleus”) cells. They are smaller and simpler than eukaryotic cells, not having nuclei and membrane-bound organelles. Furthermore, the cell features just described refer to typical cells. Mature cells are specialized and may contain unique organelles and adaptations for their specific purposes. For instance, the nerve cell has dendrites and an axon for receiving and sending impulses, while the red blood cell lacks a nucleus to make more space for transporting nutrients. Learning prompt Correctly label the cell parts in the diagram.