Cell Biology

• Cells


  The basic building blocks of living organisms
• Range of cell sizes

  • 2 - 50 cm³
• When someone first peered down a microscope at a slice of cork and drew the beans they saw, they did not know that they'd seen the building blocks of many living things - the cell
• Prokaryotes


  Simple, single-celled organisms like bacteria
• Eukaryotes


  Organisms made up of eukaryotic cells
• Living things are made of cells
• Cells can be either prokaryotic or eukaryotic
• Prokaryotic cells are small and simple (bacteria)
• Eukaryotic cells have organelles (membrane-bound structures)
• A prokaryotic cell is a single-celled organism
• Plant and animal cells


  • Have similarities and differences
• Subcellular structures in most animal cells

  • Nucleus
  • Cytoplasm
  • Cell membrane
  • Mitochondria
  • Ribosomes
• Nucleus


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


  Gel-like substance where most chemical reactions happen, containing enzymes
• Cell membrane


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


  Where most of the reactions for cell respiration take place
• Ribosomes


  Where proteins are made in the cell
• Additional structures in plant cells

  • Rigid cell wall
  • Permanent vacuole
  • Chloroplasts
• Cell wall


  Made of cellulose, supports and strengthens the cell
• Permanent vacuole


  Contains a weak solution of sugars and salts
• Chloroplasts


  Where photosynthesis occurs, containing chlorophyll
• Bacterial cells are much smaller than plant and animal cells
• Bacterial cells don't have chloroplasts or mitochondria
• Bacterial cell structure


  • Cell membrane
  • Cell wall
  • Cytoplasm
  • Single circular strand of DNA