1.2

• Knowledge of the major structural features of a cell is a prerequisite to understanding where metabolic reactions take place
• Prokaryotic cells


  Cells with no nucleus, found only in bacteria
• Eukaryotic cells


  Cells with DNA found in a membrane-enclosed nucleus, found in all higher organisms, about 1000 times larger than bacterial cells
• Our focus will be on eukaryotic cells, the type present in humans
• Eukaryotic cell components


  • Outer membrane
  • Nucleus
  • Cytosol
  • Ribosomes
  • Lysosomes
  • Mitochondria
• Cytoplasm


  The water-based material of a eukaryotic cell that lies between the nucleus and the outer membrane
• Organelle


  A minute structure within the cytoplasm of a cell that carries out a specific cellular function
• Important organelles


  • Ribosomes
  • Lysosomes
  • Mitochondria
• Ribosomes


  Sites where protein synthesis occurs
• Lysosomes


  Organelles that contain hydrolytic enzymes needed for cellular rebuilding, repair, and degradation
• Mitochondria


  Organelles responsible for the generation of most of the energy for a cell
• Mitochondrion structure


  • Outer membrane (50% lipid, 50% protein, freely permeable)
  • Inner membrane (20% lipid, 80% protein, highly impermeable)
  • Matrix
  • Intermembrane space
  • Cristae
• ATP synthase complexes


  Small spherical knobs attached to the cristae, responsible for ATP synthesis
• The invention of high-resolution electron microscopes allowed researchers to see the interior structure of the mitochondrion more clearly and led to the discovery, in 1962, of ATP synthase complexes
• Knowledge of the major structural features of a cell is a prerequisite to understanding where metabolic reactions take place
• Prokaryotic cells


  Cells with no nucleus, found only in bacteria
• Eukaryotic cells


  Cells with DNA found in a membrane-enclosed nucleus, found in all higher organisms, about 1000 times larger than bacterial cells
• Our focus will be on eukaryotic cells, the type present in humans
• Eukaryotic cell components


  • Outer membrane
  • Nucleus
  • Cytosol
  • Ribosomes
  • Lysosomes
  • Mitochondria
• Cytoplasm


  The water-based material of a eukaryotic cell that lies between the nucleus and the outer membrane
• Organelle


  A minute structure within the cytoplasm of a cell that carries out a specific cellular function
• Important organelles


  • Ribosomes
  • Lysosomes
  • Mitochondria
• Ribosomes


  Sites where protein synthesis occurs
• Lysosomes


  Organelles that contain hydrolytic enzymes needed for cellular rebuilding, repair, and degradation
• Mitochondria


  Organelles responsible for the generation of most of the energy for a cell
• Mitochondrion structure


  • Outer membrane (50% lipid, 50% protein, freely permeable)
  • Inner membrane (20% lipid, 80% protein, highly impermeable)
  • Matrix
  • Intermembrane space
  • Cristae
• ATP synthase complexes


  Small spherical knobs attached to the cristae, responsible for ATP synthesis
• The invention of high-resolution electron microscopes allowed researchers to see the interior structure of the mitochondrion more clearly and led to the discovery, in 1962, of ATP synthase complexes