Skip to main content
Back

Cell Structure and Function - Anatomy & Physiology

Control buttons has been changed to "navigation" mode.
1/28

Terms in this set (28)

  • What is a cell?
    The cell is the simplest collection of matter that can live and is the fundamental unit of life.
  • What are the four structures every cell has?
    1. Plasma membrane, 2. Chromosomes (DNA), 3. Ribosomes, 4. Cytoplasm.
  • Why are cells generally small?
    Cells are small because surface area must be large enough relative to volume to allow efficient nutrient uptake and waste disposal by diffusion.
  • What are the main differences between prokaryotic and eukaryotic cells?
    Prokaryotes lack a nucleus and membrane-bound organelles, are smaller, and have less DNA. Eukaryotes have a nucleus, membrane-bound organelles, and larger genomes.
  • What is the function of the nucleus?
    The nucleus stores genetic information (DNA), controls cell activities, and is separated from cytoplasm by the nuclear envelope with pores regulating material exchange.
  • What are ribosomes and their function?
    Ribosomes are RNA-protein particles that synthesize proteins by translating mRNA instructions from DNA.
  • What is the endomembrane system?
    A group of membranous organelles including the ER, Golgi apparatus, lysosomes, and vesicles that manufacture, distribute, and break down molecules.
  • Difference between rough and smooth endoplasmic reticulum (ER)?
    Rough ER has ribosomes and synthesizes proteins; smooth ER lacks ribosomes and synthesizes lipids, stores calcium, and detoxifies substances.
  • What is the role of the Golgi apparatus?
    The Golgi modifies, sorts, and ships proteins and lipids received from the rough ER to their destinations.
  • What are lysosomes and their function?
    Lysosomes are animal cell organelles containing digestive enzymes that break down food, waste, and damaged organelles.
  • What is the function of mitochondria?
    Mitochondria perform cellular respiration, converting glucose and oxygen into ATP, carbon dioxide, and water.
  • What is the function of chloroplasts?
    Chloroplasts conduct photosynthesis, converting solar energy, carbon dioxide, and water into glucose and oxygen.
  • What is the cytoskeleton and its functions?
    A network of fibers (microfilaments, intermediate filaments, microtubules) that maintain cell shape, enable movement, and organize organelles.
  • What are cilia and flagella?
    Locomotor appendages made of microtubules that protrude from cells and move by bending.
  • What is the plasma membrane composed of?
    A phospholipid bilayer with embedded proteins and carbohydrates, acting as a selectively permeable barrier.
  • What does 'fluid mosaic model' mean?
    The membrane is a fluid bilayer of lipids with proteins embedded, allowing lateral movement and dynamic function.
  • How does cholesterol affect membrane fluidity?
    Cholesterol stabilizes membrane fluidity by reducing it at high temperatures and preventing tight packing at low temperatures.
  • What are the types of membrane proteins?
    Peripheral proteins (surface-bound) and integral proteins (embedded), including transmembrane proteins that span the membrane.
  • What is passive transport?
    Movement of substances across membranes without energy, including simple diffusion, osmosis, and facilitated diffusion.
  • What is active transport?
    Energy-requiring movement of substances against their concentration gradient, often using membrane proteins.
  • What is osmosis?
    The diffusion of water across a selectively permeable membrane from low to high solute concentration.
  • What is the sodium-potassium pump?
    A primary active transport protein that moves Na+ out and K+ into cells using ATP, essential for nerve and muscle function.
  • What are exocytosis and endocytosis?
    Exocytosis expels large molecules via vesicles; endocytosis brings large molecules into the cell by vesicle formation.
  • How do plant and animal cells differ in organelles?
    Plant cells have chloroplasts, cell walls, and central vacuoles; animal cells have lysosomes and centrioles.
  • What is the function of the cell wall in plants?
    Provides rigid structural support and protection, made mainly of cellulose.
  • What are intercellular junctions in animal cells?
    Tight junctions (seal cells), anchoring junctions (link cells), and gap junctions (allow communication).
  • Why is surface area important for cells?
    Large surface area relative to volume allows efficient diffusion of nutrients and wastes.
  • What molecules easily cross the lipid bilayer?
    Small nonpolar molecules like O2 and CO2 cross easily; large, polar, or charged molecules require transport proteins.