Cells

• Prokaryotes


  Organisms that are not made up of cells with a nucleus
• Eukaryotes


  Organisms that are made up of cells with a nucleus
• Cell types


  • Prokaryotic cells
  • Eukaryotic cells
• Prokaryotic cells


  • Do not have a nucleus
  • Have a single circular strand of DNA floating in the cytoplasm
• Eukaryotic cells


  • Have a true nucleus
  • Have membrane-bound organelles like mitochondria and chloroplasts
• Organisms can be either prokaryotes or eukaryotes
• Cell structures


  • Nucleus
  • Cytoplasm
  • Cell membrane
  • Cell wall
  • Mitochondria
  • Ribosomes
  • Chloroplasts
  • Vacuole
• Nucleus


  Contains the genetic material that controls the activities of the cell
• Cytoplasm


  The jelly-like substance inside the cell where most chemical reactions take place
• Cell membrane


  Holds the cell together and controls what goes in and out of the cell
• Mitochondria


  Where most of the reactions for cellular respiration take place, providing energy for the cell
• Ribosomes


  Where proteins are made in the cell
• Plant cells


  • Have a rigid cell wall made of cellulose
  • Have a permanent vacuole containing cell sap
  • Have chloroplasts where photosynthesis occurs
• Animal cells


  • Do not have a cell wall
  • Do not have chloroplasts or a permanent vacuole
• Bacterial cells are much smaller than plant and animal cells
• Bacteria are prokaryotes
• Bacterial cells


  • Do not have a true nucleus
  • Have a single circular strand of DNA floating in the cytoplasm
  • May contain plasmids - small rings of DNA
• Bacterial cells do not have organelles like mitochondria or chloroplasts
• You could be asked to estimate the area of a subcellular structure in an exam