Eukaryotic Cell Structure

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Eukaryotic Cell Structure
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Essential Questions

• What are the functions of the major cell
  structures?

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Organelles

• Little organs
• Specialized structures of the cell
• Each organelle has unique functions
• These organelles allow the cell to function
  properly

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Organelle Groups

• Cell biologists divide organelles into three
  groups based on their location
• Nucleus nucleolus, chromatin, nuclear envelope
• Cytoplasm mitochondria, vacuole, Golgi
  apparatus, centrioles, lysosomes, ribosomes,
  chloroplasts, endoplasmic reticulum (ER)
• Surface cell membrane, cell wall

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Group 1 - Nucleus

• 1. Nucleus
• Control center of the cell
• Contains nearly all cell DNA
• 2. Nuclear Envelope
• Surrounds the nucleus
• Contains nuclear pores, which allow material to
  move into and out of the nucleus

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Nucleus cont

• 3. Chromatin
• Consists of DNA bound to a protein
• Condenses to form chromosomes
• 4. Nucleolus
• Small, dense region
• Assembly of ribosomes begin here

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Group 2 - Cytoplasm

• The portion of the cell outside the nucleus
• Contains many organelles
• Gel-like substance that protects the organelles
• Allows movement

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Cytoplasmic organelles

• 1. Ribosome
• Small particles of RNA and protein found
  throughout the cytoplasm
• Responsible for the assembly of proteins
• Follows coded instructions from the nucleus
• Numerous in cells active in protein synthesis

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• 2. Endoplasmic Reticulum (ER)
• Site where lipid components, proteins and other
  materials are exported from the cell
• Rough ER
• Involved in the synthesis of proteins
• Ribosomes are found on its surface
• Smooth ER
• Contains collections of enzymes
• Synthesis of membrane lipids
• Detoxification of drugs

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• 3. Golgi Apparatus (aka Golgi Bodies)
• Proteins in the rough ER move next into the Golgi
  Apparatus
• It modifies, sorts, and packages proteins for
  storage or secretion
• Ships proteins to their final destination

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• 4. Lysosomes
• Small organelles filled with enzymes
• clean up crew
• Digestion, or breakdown, of lipids,
  carbohydrates, and proteins so the rest of the
  cell can use them
• Removes dead organelles

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• 5. Vacuoles
• Saclike structures that store materials
• Plant cells the vacuole is a single, large
  central organelle filled with liquid
• Allows for support of leaves and flowers
• Help maintain homeostasis
• Also found in some animal cells

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• 6. Mitochondria
• Power house of the cell
• Responsible for the cell energy
• Converts stored energy in food into compounds
  that the cells can use
• Contains its own DNA
• Some scientists believe that mitochondria, at one
  point, may have been a prokaryotic cell

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• 7. Chloroplasts
• Only found in plant cells
• Capture energy from sunlight and convert it into
  chemical energy (called photosynthesis)
• Contains chlorophyll (Gives plants its color)
• Contains its own DNA
• Some scientists believe that mitochondria, at one
  point, may have been a prokaryotic cell

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• 8. Centrioles
• Come from structures called microtubules
• Located near the nucleus
• Help to organize cell division
• Only in Animal Cells

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Group 3 - Surface

• Cytoskeleton (cell skeleton)
• A network of protein filaments that help the cell
  maintain its shape
• Also aids in movement (Flagellum and Cilia)

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• 1. Cell membrane
• Cell membrane regulates what enters and leaves
  the cell
• Provides protection and support
• 2. Cell wall
• Main function is to provide support and
  protection
• Only in plant cells

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