Eukaryotic Cell

• Nucleus


  Control Center of the Cell
• Nucleus


  • Double layered covering called nuclear membrane
  • Nuclear membrane has pores of diameter about 80-100 nm
  • Colorless dense sap known as Nucleoplasm
  • Contains round shaped Nucleolus and network of chromatin fibers
  • Fibers composed of DNA and protein histone
  • Fibers condense to form chromosomes during cell division
  • Chromosomes contain stretches of DNA called genes
  • Genes transfer hereditary information
• Cell Wall

  • Non-living outermost covering
  • Made up of cellulose, hemicellulose, and pectin
  • Can be tough, rigid, or flexible
  • Thickness varies from 50 - 1000 A*
• Plastids


  Double membrane-bound organelles found inside plants and some algae
• Chromoplasts


  • Produce and store pigments
  • Responsible for colors in leaves, fruits, flowers, and vegetables
• Leucoplasts

  • Colorless Plastids that store foods
  • Found in storage organs like fruits, tubers, and seeds
• Cytoskeleton


  Framework of the Cell
• Cytoskeleton


  • Formed by microtubes and microfilaments
  • Microtubes made of tubulin
  • Microfilaments made of actin
• Cytoplasm

  Occurs inside the plasma membrane
• Cytosol


  The fluid portion of the Cytoplasm
• Karyoplasm


  Protoplasm inside the Nucleus
• Cytoplasm


  • Jelly-like material formed by 80% water
  • Contains Cytosol and various particles
  • Particles include proteins, carbohydrates, nucleic acids, lipids, and inorganic ions
• Most Bacteria are 1 - 10 Microns
• Eukaryotic Cells are 10 - 100 Microns
• Micron = Micrometer = 1/1,000,000 meter
• Diameter of Human Hair is approximately 20 Microns
• Organelles


  Do the work of cells
• Mitochondria


  • Small, rod-shaped organelles
  • Bounded by two membranes
  • Inner membrane has shelf-like projections called Cristae
  • Contains matrix filled with enzymes
  • Contain their own DNA
• Ribosome


  Protein Factories of Cell
• Ribosome


  • Small granular structures made up of RNA and proteins
  • RNA produced in the nucleus
• Endoplasmic Reticulum (ER)


  Manufacturers and Shipper of the Cell
• Endoplasmic Reticulum


  • Network of tubular and vesicular structures
  • Connected to nuclear membrane and cell membrane
  • Two types: smooth and rough
• Golgi Body

  Packaging Counters of the Cell
• Golgi Body


  • Discovered by Camillo Golgi
  • Formed by stacks of membranous sacs called Cisternae
  • Has Cis Face and Trans Face
• Vacuoles


  Storage Tanks of the Cell
• Vacuoles


  • Single membrane sac filled with liquid or sap
  • Temporary in animal cells, large in plant cells
• Lysosomes


  Suicide Bags of Cell
• Lysosomes


  • Small, spherical, single membrane sac
  • Filled with Hydrolytic enzymes