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Cells: The Living Units - Anatomy & Physiology

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Terms in this set (25)

  • What are the three major regions of a cell?
    Plasma membrane (outer boundary), cytoplasm (contains organelles), and nucleus (controls cellular activities).
  • What are the basic activities of a cell?
    Obtain nutrients, make molecules needed to survive, dispose of wastes, maintain shape and integrity, and replicate itself.
  • Describe the structure of the plasma membrane.
    A fluid mosaic model with a phospholipid bilayer and embedded proteins, including integral and peripheral proteins.
  • What is the function of integral proteins in the plasma membrane?
    They are firmly embedded in the lipid bilayer and can act as receptors or channels for selective substance transport.
  • What does the term 'selectively permeable' mean regarding the plasma membrane?
    The membrane allows some substances to enter or leave the cell while blocking others.
  • What is simple diffusion?
    Movement of molecules down their concentration gradient directly through the phospholipid bilayer.
  • What is osmosis?
    Diffusion of water molecules across a membrane through specific channels or the lipid bilayer.
  • Define facilitated diffusion.
    Movement of molecules down their concentration gradient through an integral protein channel.
  • What is active transport?
    Movement of molecules against their concentration gradient using energy (ATP) via transport proteins.
  • What are the two main types of endocytosis?
    Phagocytosis (cell eating) and pinocytosis (cell drinking).
  • Describe receptor-mediated endocytosis.
    Specific molecules bind to receptor proteins in coated pits, which invaginate and form vesicles to bring substances into the cell.
  • What is exocytosis?
    A process where substances enclosed in vesicles are released out of the cell by vesicle fusion with the plasma membrane.
  • What are ribosomes and their function?
    Made of proteins and rRNA, ribosomes are the site of protein synthesis (translation).
  • Differentiate between free and bound ribosomes.
    Free ribosomes function in the cytosol; bound ribosomes are attached to rough ER and make proteins for export or membrane renewal.
  • What are the functions of rough and smooth endoplasmic reticulum?
    Rough ER synthesizes secreted proteins; smooth ER performs lipid metabolism, drug detoxification, and stores Ca2+.
  • What is the role of the Golgi apparatus?
    Sorts and packages proteins from rough ER and sends them to their proper destinations.
  • What are lysosomes and their function?
    Membrane sacs containing digestive enzymes that break down unwanted substances; act as the cell's demolition crew.
  • What is the function of mitochondria?
    Generate most of the cell's energy by producing ATP through chemical bond energy release.
  • What are peroxisomes and their role?
    Membrane sacs with enzymes that neutralize free radicals, break down poisons, and fatty acids.
  • Describe the cytoskeleton and its components.
    Network of rods including microfilaments (actin), intermediate filaments (tough fibers), and microtubules (tubulin) that support cell shape and movement.
  • What is the nucleus and its main parts?
    Control center housing DNA; main parts are nuclear envelope (double membrane with pores), nucleolus (ribosome assembly), and chromatin (DNA-protein complex).
  • What are the phases of the cell life cycle?
    Interphase (G1-growth, S-DNA synthesis, G2-preparation) and Mitotic phase (mitosis and cytokinesis).
  • What happens during mitosis?
    Division of the nucleus into two daughter nuclei through prophase, metaphase, anaphase, and telophase.
  • What is cytokinesis?
    Physical separation of the parent cell into two daughter cells following mitosis.
  • How does cell specialization relate to cell shape?
    Cell shape and organelle arrangement relate to specific functions, e.g., muscle cells are elongated for contraction.