Cell Structure and Organelles

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Cell Structure and Organelles
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Cell wall

• functions to protect and support cells
• made of a rigid material called cellulose in
  plants
• animal cells dont have cell walls

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Cell Membrane

• protects the cell
• controls the movement of materials in and out of
  the cell (selectively permeable)
• found in all cells

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Cell Membrane cont.

• The cell membrane is made of phospholipids that
  are constantly moving.
• Small molecules (e.g. CO2, O2, H2O) can diffuse
  through the phospholipids unassisted.
• Proteins are embedded in the membrane that act as
  channels to move larger molecules in and out.

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Cytoplasm

• The cytoplasm is everything inside the cell
  membrane, but outside the nucleus.
• The cytoplasm is a jelly-like substance made
  mostly of water that fills the cell.
• Organelles are located in the cytoplasm.

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Nucleus and Nucleolus

• Nucleus
• control center of the cell
• contains chromosomes (made of DNA)
• Nucleolus
• a dense area (darker area) within the nucleus
• ribosomes are produced in the nucleolus

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Mitochondrion

• tiny, oval-shaped organelle that provides cells
  with energy (ATP)
• mitochondria are the site of aerobic cellular
  respiration
• ATP is used by other organelles for energy for
  cell processes

• ____________ _________ ________ ? ________
  ____________

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Ribosome

• ribosomes are microscopic spheres attached to the
  endoplasmic reticulum or floating in the
  cytoplasm
• ribosomes make proteins

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Endoplasmic Reticulum

• a twisting network of canals
• functions to transport materials throughout the
  cell
• may have ribosomes attached to it (rough ER)
  smooth ER has no ribosomes attached

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Golgi Apparatus

• flattened sacs that produce vesicles (transport
  sacs)
• they function to modify and store cellular
  secretions
• (e.g. proteins)

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Lysosome

• saclike structure formed by the Golgi apparatus
• contains enzymes that can break down large
  molecules or worn out cell parts

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Vacuole

• fluid-filled space containing water, sugar, and
  proteins
• helps with water regulation in plants

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• vacuoles can also store food or help some
  organisms move

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Centriole

• small protein structures critical to cell
  division (paired)
• not found in plant cells

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Chloroplast

• found only in green plants and some protists
• Contains the light sensitive protein pigment
  chlorophyll

• CO2 H2O sunlight ? sugar O2

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Chloroplast

• convert sunlight into food for the cell via
  photosynthesis

• ____________ _________ ________ ? ________
  ____________

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Cilia and Flagella

• fine protein fibres used for locomotion
• Cilia short, may be numerous on cell surface
• Flagella long, usually few in number on cell
  surface

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Cytoskeleton

• protein fibres network that help anchor
  organelles in place and give structure to the cell

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Plant Cell

• electron micrograph of a typical plant cell
• What structures are found only in plant cells?

• cell wall
• large vacuole
• chloroplast

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Animal Cell

• electron micrograph of a typical animal cell
• What structures are found only in animal cells?

• cilia
• flagella
• centrioles

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What structures are found in both plant and
animal cells?

• What structures are found in both?
• cell membrane
• cytoplasm
• nucleus/nucleolus
• mitochondrion
• ribosomes
• endoplasmic reticulum
• lysosomes
• golgi apparatus

• cilia, flagella centrioles