CELL STRUCTURE

• Prokaryotic Cell vs Eukaryotic Cell

  SIMILARITIES:

  • characterized by the existence of:
  • Plasma membrane (outer, selective barrier of the cell)
  • Cytosol (semifluid substance in which all other components are suspended)
  • Cytoplasm (in prokaryotes, it is the region inside the cell; in eukaryotes, it is the region between the nucleus and the plasma membrane)
  • Chromosomes (tightly packaged DNA)
  • Ribosomes (protein factories)
• Prokaryotic vs Eukaryotic Cells

  DIFFERENCES:

  • Eukaryotic cells has a nucleus
  • Location of DNA in Prokaryotic Cells is called nucleoid; it has no membranes)
• Eukaryotic Cells


  Classified into two: plant and animal cells

  • plant cells make their own food through photosynthesis
  • animal cells consume food through other organisms
• Central Vacuole


  Involved in food storage, breakdown of waste products, and hydrolysis of macromolecules; its enlargement is a major mechanism of plant growth
• Chloroplast


  Responsible for conducting photosynthesis.
• Plasmosdesmata


  Channels that connect the cytoplasms of adjacent plant cells, thus allowing transport of materials between them.
• Cell Wall


  Thick wall outside the plasma membrane; makes plant cells rigid.
• Nucleus


  Contains chromosomes, which are made of chromatin (DNA & Proteins),

  and nucleolus, where ribosomal subunits are made.
• Ribosome


  Two subunits made up of ribosomal RNA and proteins; used for protein synthesis
• Endromembrane System


  Regulates protein traffic and performs metabolic functions
• Endoplasmic Reticulum


  Extensive network of tubules and sacs comprised off Smooth ER, Rough ER, Golgi Apparatus, and Lysosome.
• Smooth Endoplasmic Reticulum


  Functions in lipid synthesis, carbohydrate metabolism, Ca2+ storage, and detoxification of poisons and drugs.
• Rough Endoplasmic Reticulum


  Aids in protein synthesis due to attached proteins.
• Golgi Apparatus


  Modifies proteins and sorts products that are later packaged into vesicles.
• Lysosomes


  A sac containing hydrolytic enzymes that breaks down susbtances.
• Mitochondria


  Functions in cellular respiration, a process that powers the cell by converting chemical energy to ATP
• Chloroplast


  functions in photosynthesis, a process that stores energy by converting light energy to chemical energy
• Peroxisomes


  Vesicle that performs metabolic redox reactions, producing hydrogen peroxide in the process, which is then converted to water or used for other reactions