2.1 The Structure

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2.1The Structure Functions of Eukaryotic
Cells
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Chloroplasts

• Derived from photosynthetic bacteria has DNA
• A double membrane bound, solar energy capturing
  organelle
• Internal thylakoid membrane is stacked (grana)
  and has pigments for photosynthesis.
• Liquid medium around thylakoid called stroma.

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Chloroplast Micrograph
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Photosynthesis

• It takes place in the thylakoid membranes and
  stroma
• Pigments like chlorophyll capture solar energy to
  make cellular food (ie glucose)
• Cyanobacteria closely related to chloroplasts in
  higher plants.

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Mitochondria

• Have their own DNA
• A double membrane bound organelle
• Internal cristae membrane is folded for increased
  surface area.
• Aerobic cellular respiration
• occurs in the cristae and
• the matrix
• The liquid medium inside
• the cristae is called
• the matrix.

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Mitochondria Micrograph
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Mitochondria

• Breaks down high-energy organic molecules
  (cellular respiration) to store in chemical bonds
  as chemical potential energy.
• In addition to glucose, it can
• also use lipids and proteins
• The released energy is
• stored in the form of
• ATP

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Cell Walls

• It is found in plants, fungi, many protists
• Surrounds cell membrane for support and
  protection (ie Turgor Pressure in plants)
• Made of either polysaccharides, glycoproteins or
  both.
• It is porous and does little to control access to
  the cell.

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Cytoskeleton

• It is an internal network of protein fibres
• Its made of 3 fibre types
• Microfilaments
• Microtubules
• Intermediate filaments
• 3 functions
• mechanical support
• anchors organelles
• help move substances

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Microfilament Micrograph
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Cell Movement

• Microtubules microfilaments
• - slide against one another for internal cell
  movement
• Cilia
• Short
• Used to move substances outside human cells
• Flagella
• Whip-like extensions
• Found on sperm cells

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Cilia Flagella Structure

• Both are extensions from the cell membrane.
• Theyre bundles of microtubules
• Cilia are short and in large numbers for
  movement.
• Flagella are few but longer for locomotion.

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Cell (Plasma) Membrane

• It wraps the cell contents its semi-permeable.
• Its a double layer of phospholipids embedded
  proteins
• This fluid mosaic model has the hydrophillic
  heads oriented to the outside and hydrophobic
  tails to the inside. This controls access in
  out of the cell.
• Includes cholesterol, glycoproteins and
  glycolipids.

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Cell Membrane Micrograph
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Phospholipids

• They are lipid molecules with one glycerol, 2
  fatty acids and a phosphate group.
• The polar head is hydrophyllic head and the
  non-polar tail is hydrophobic.
• Most of the fatty acid chains are saturated.

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Membrane Proteins

• 1. Channels or transporters
• Move molecules in one direction
• 2. Receptors
• Recognize certain chemicals

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Membrane Proteins

• 3. Cytoskeleton
• Microtubules microfilaments
• 4. Enzymes
• Catalyze production of substances

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End Part 3