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Cell Structures Prokaryotic and Eukaryotic

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					Cell Structures:
Prokaryotic and
Eukaryotic
Content Standard Four
The Main Idea…

  All organisms share a
   common feature—the cell.
  A cell is the smallest unit
   that can carry out all the
   functions of life. Thus, a cell
   is a living system.
Breaking it down…
(don’t write)
  The root word karyose means “kernel”,
   which represents the nucleus of a cell in
   biology.
  The prefix pro- means “before” so
   prokaryotic means “before a nucleus”
  The prefix eu- means “true” so eukaryotic
   means “has a true nucleus”
Two basic types of cells

 1. Eukaryotic – has true nucleus
 2. Prokaryotic – lacks a true nucleus
Prokaryotic Vs. Eukaryotic

  Both perform similar functions in same
   way
  Both enclosed by cell membrane, filled
   with cytoplasm, have ribosomes and
   DNA.
So how are they
different?...
Eukaryotic cells…

  Are larger and more detailed
  Have a distinct nucleus and other cell
   structures called organelles
    The organelles perform certain jobs to
     sustain the life of the cell
  Examples: plants, animals, protists, and
   fungi
Prokaryotic cells…

  Does NOT contain nucleus or
   membrane-bound organelles.
  Most of the jobs that sustain the cell’s life
   occurs in the cytoplasm.
    Cytoplasm is the fluid that fills most of the
     cell’s space
  Examples: all bacteria
  The Organelles of a Cell
NUCLEUS- Brain of cell
 Directs and controls cell
  activities
 Surrounded by a two-
  layer structure called
  nuclear membrane.
 Has pores, or openings,
  that act as doorway to
  allow materials to pass in
  and out
  The Organelles of a Cell
 Has DNA, which controls
  cell operation and stores
  genetic information in
  structures call
  chromosomes.
 Has a small dense region
  called nucleolus, which
  is where RNA is stored
  and ribosomes are made.
Plant Cell Vs. Animal Cell




                  ANIMAL CELL
   PLANT CELL
 The Organelles of a Cell
CELL MEMBRANE-
 Thin layer that
  surrounds the
  cytoplasm (liquid filler)
 The main jobs are to
  protect, support, and
  control what enters and
  leaves cell (think back
  to last week)
 The Organelles of a Cell
ENDOPLASMIC RETICULUM (ER)
 Acts as a highway to allow molecules to
   move around the cell
 Two types of ER:
  1. Rough ER- has attached ribosomes,
     where large amounts of proteins are
     made
  2. Smooth ER- no ribosomes attached,
     involved in regulating cell processes
The Organelles of a Cell

 RIBOSOMES
  Where proteins are made
  Can be scattered throughout cytoplasm
   in the cell or attached to the Endoplasmic
   Reticulum (ER)
  Formed in nucleolus of the nucleus
The Organelles of a Cell

 GOLGI BODIES (AKA: Golgi Apparatus)
  “packages and delivers” proteins that the
   ER makes according to where they will
   be sent.
  Example: proteins that will be sent to
   nucleus are packaged differently than
   proteins being sent to cell membrane.
The Organelles of a Cell

 MITOCHONDRIA- “Powerhouse”
  Sites of cellular respiration resulting in
   ATP
  ATP are energy molecules that can be
   broken down to release energy in forms
   the cell can use
  Cells that use more energy, like muscle
   cells, have more mitochondria.
The Organelles of a Cell

 LYSOSOMES – “cleanup crew”
  Carry out the digestive processes of the
   cell
  Contain enzymes that help digest harmful
   or unwanted materials from the cell, like
   old organelles.
  Rare in plant cells, but common in animal
The Organelles of a Cell

  The organelles we’ve covered so far are
   common in most eukaryotic cells, like
   animal, plant, fungi, and protist.
  There are few other organelles that are
   common in some eukaryotic cells.
The Organelles of a Cell

 CELL WALL
  A rigid structure that
   surrounds the cell
   membrane in plant cells
  It gives additional
   structure and support
  Common in plant,
   bacteria, and fungi, some
   protist have them.
   NEVER in animal though
The Organelles of a Cell
 CHLOROPLAST
  Contains a green pigment called chlorophyll,
   which traps energy from sunlight and gives
   plants their green color
  It uses the energy to produce energy rich food
   molecules (sugars) through a process called
   photosynthesis
  Common in plants, protist, including algae, and
   bacteria. NEVER in animals.
The Organelles of a Cell
 VACUOLES
  Stores water and other dissolved materials
  Plants have these because unlike animal, they
   cannot move to find water or have skeletal
   systems for support.
  The pressure from the large liquid-filled
   structure gives added support for leaves and
   flowers
  Animals do have several small vacuoles only to
   transport material within the cell and plant have
   one large central vacuole for storage.
The Organelles of the Cell

 CENTRIOLES
  Help in cell division during mitosis
  Located near the nucleus
  Only found in animal cells
   Cell        Function        Prokaryote        Eukaryote
Component
                               Bacteria       Plant    Animal

Cytoplasm     Site of
              reactions
                               Present      Present   present
Nucleus       Controls cell
              activities
                               Absent       Present   Present
Cell          Gives shape,
              regulation
                               Present      Present   Present
Membrane
Cell Wall     Support
                               Present      Present   Absent
Mitochondia   Cellular
              respiration
                               Absent       Present   Present
Lysosome      Digestion
                               Absent       Present   Present
Ribosome      Makes proteins
                               Present      Present   Present
ER            Transport
                               Absent       Present   Present
Chloroplast   photosynthesis
                               Absent       present   Absent

				
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posted:8/12/2011
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