Organelle Structure and Function

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Organelle Structure and Function
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Review

• Prokaryotes simple celled organisms
• No nucleus
• Eukaryotic cells multicellular organisms
• Nucleus
• organelles

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Cytoskeleton

• Webs of proteins and fibers that make up a
  skeleton for the cell.
• The cytoskeleton holds the cell together and
  keeps the cells membrane from collapsing.
• Consists of the microtubules, and microfilaments

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Nucleus

• Functions of the cell are controlled by the
  nucleus
• Nucleus surrounded by a double membrane called
  the nuclear envelope.
• Nuclear membrane is made a two lipid bilayers.

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Nucleus

• The nucleus contains the DNA
• The nucleus contains the nucleolus.
• The nucleolus contains the RNA.
• RNA makes the proteins

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Nucleus

• The hereditary information of a eukaryotic cell
  is in the cells DNA, most of which is stored in
  the nucleus

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Ribosomes

• Cells make proteins called ribosomes.
• Ribosomes are made of proteins and RNA.
• Ribosomes are found in the cytoplasm and on the
  endoplasmic reticulum.
• Ribosomes are used to make new organelles.

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Endoplasmic Reticulum

• The endoplasmic reticulum or ER is an extensive
  system of internal membranes that move proteins
  and other substances through the cell.
• The ER is made of the lipid bilayer.

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Rough Endoplasmic Reticulum

• The endoplasmic reticulum that is studded with
  ribosomes is called rough ER.
• The rough ER help transport the proteins that are
  made by its attached ribosomes.
• As each protein is made crosses the ER membrane
  and enters the ER.
• The portion of the ER that contains the completed
  protein then pinches off and forms a vesicles.

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Vesicle

• A vesicle is a small membrane bound sac that
  transports substances in cells.
• Because these proteins are enclosed inside a
  vesicles, these proteins are kept separate from
  proteins that are produced by free ribosomes.

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Smooth Endoplasmic Reticulum

• The rest of the ER is called the smooth ER
  because it lacks ribosomes
• The smooth ER is used for making lipids and
  breaking down toxic substances.

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Golgi Appartatus

• Vesicles that contain newly made proteins move
  through the cytoplasm into the golgi apparatus.
• The golgi apparatus is a set of flattened
  membrane bound sacs that serves as the packaging
  and distribution center of the cell.
• Enzymes inside the Golgi Apparatus modify the
  proteins that are received in the vesicles from
  the ER.

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Golgi Apparatus

• The modified proteins are then put into vesicles
  and bud from the surface of the Golgi Apparatus

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Lysosomes

• Lysosomes are vesicles within the cell that
  contain the cells digestive enzymes.
• Lysosomes destroy worn out cell parts, and dead
  or dying cells.

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Mitochondria

• A mitochondria or mitochondrion is an organelle
  that harvests energy from organic compounds to
  make ATP, the main energy currency in cells.
• Most ATP is made in the mitochondria.
• Cells that require large amounts of energy like
  muscle cells have hundreds of mitochondria within
  the cell.

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Mitochondria

• The outer membrane is smooth and the inner
  membrane is greatly folded, to add its surface
  area.
• In the mitochondrial matrix is where the chemical
  reactions take place in order to form the ATP
  necessary for the cells energy.

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Mitochondria

• The mitochondria contain their own DNA.
• Mitochondria also have DNA and ribosomes, and
  mitochondria make some of their own proteins.
• This gives mitochondria the ability to replicate
  on its own.

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Structure of Plant Cells

• All other organelles are in animal and plant
  cells.
• Plants have three additional organelles
• Cell wall
• Chloroplasts
• Central vacuole

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Cell Wall

• The cell membrane of a plant cell is surrounded
  by a thick cell wall composed of carbohydrates,
  proteins, and cellulose.
• The cell wall helps support and maintain the
  shape of the cell.
• It protects the cell from damage, and connects it
  with adjacent cells.

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Chloroplasts

• Plant cells contain one or more chloroplasts.
• Chloroplasts are organelles that use light energy
  to make carbohydrates from carbon dioxide and
  water.
• Chloroplasts along with mitochondria, supply much
  of the energy need to power the activities of the
  plant cell.
• Chloroplast are equivalent to the mitochondria in
  animal cells.

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Central Vacuole

• Much of the plant cells volume is take up by the
  central vacuole.
• The central vacuole stores water and may contain
  many substances, including ions, nutrients, and
  wastes.
• When the central vacuole is full it makes the
  cell rigid.
• The rigidity allows the plant to stand upright.