Cells

• What is the basic living structural unit of the body?

  A cell
• What elements primarily form a cell?

  Carbon, oxygen, hydrogen, nitrogen
• What are the functions of different types of cells?

  • Protection and support: epithelial cells
  • Communication: neurons
  • Energy production: during cellular metabolism
  • Movement: skeletal muscle cells
  • Inheritance: sperm and oocytes
  • Transport: red blood cells
• What are the principal parts of a cell?

  Plasma membrane, cytoplasm, nucleus
• What is the function of the plasma membrane?

  Forms a barrier between intracellular and extracellular fluid
• What is the structural framework of the plasma membrane?

  Lipid bilayer
• What are the extensions of the plasma membrane?

  Cilia, flagella, microvilli
• What is the function of cilia?

  Move materials/fluids over cell surface
• What is the function of flagella?

  Moves the entire cell
• What is the function of microvilli?

  Increase surface area for absorption
• What does selective permeability of the plasma membrane allow?

  Regulates what enters and exits the cell
• What types of substances can passively cross the plasma membrane?

  Small molecules like O₂ and CO₂
• What is passive membrane transport?

  Movement down concentration gradient using kinetic energy
• What is active membrane transport?

  Uses ATP to move substances against concentration gradient
• What is simple diffusion?

  Net movement from higher to lower concentration
• What is facilitated diffusion?

  Molecules transported by ion channels or carrier molecules
• What is osmosis?

  Net movement of water through a selectively permeable membrane
• What is tonicity?

  Measure of osmotic pressure difference between solutions
• What happens to cells in isotonic solutions?

  No effect on the cells
• What happens to cells in hypertonic solutions?

  Causes crenation of the cells
• What happens to cells in hypotonic solutions?

  Causes haemolysis of the cells
• What is cytoplasm?

  All cellular contents within the plasma membrane
• What is cytosol?

  Fluid portion of cytoplasm containing dissolved substances
• What is the function of the cytoskeleton?

  Provides strength and support to the cell
• What are organelles?

  Specialized structures performing specific functions in the cell
• What are the membranes organelles?

  Mitochondria, ER, Golgi apparatus, lysosomes, peroxisomes
• What is the function of ribosomes?

  Sites of protein synthesis
• What is the difference between free and fixed ribosomes?

  Free ribosomes synthesize proteins for the cell
• What is the rough ER's function?

  Storage, transport, and packaging of proteins
• What is the smooth ER's function?

  Synthesizes lipids and detoxifies drugs
• What is the function of the Golgi apparatus?

  Storage, modification, sorting, and packaging of proteins
• Why are mitochondria called the 'Powerhouses of the cell'?

  They produce most of a cell's ATP
• What is the function of lysosomes?

  Intracellular removal of worn-out organelles
• What are peroxisomes important for?

  Oxidation of amino acids and detoxification
• What is the function of proteasomes?

  Degrade damaged proteins by proteolysis
• What is the centrosome's role?

  Region for microtubule formation near the nucleus
• What are centrioles important for?

  Forming the mitotic spindle during cell division
• What are the components of the nucleus?

  Nuclear envelope, nuclear pore, nucleolus
• What is the function of nuclear pores?

  Control movement between nucleus and cytoplasm
• What does the nucleolus produce?

  Ribosomes