Transcript Prokaryote versus Eukaryotes Cell Structure

Cell Structure
Bellwork
List some characteristics that distinguish
a bacterium from a plant.
Objectives
List characteristics common to all cells
List characteristics that distinguish
prokaryotic and eukaryotic cells
Describe differences between plant and
animal cells
Key Terminology
Prokaryotic
Eukaryotic
Nucleoid
Membrane-bound
Plastid
Cytoplasm
Protista
Discovery of Cells
Came with the invention of the microscope
Key Findings
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Robert Hooke, 1665
 examined cork with an early compound microscope
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Leeuwenhoek, 1665
 examined pond water with a single-lens
microscope
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Scheiden, 1838
 concluded all plants made of cells
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Schwann, 1839
 concluded all animals made of cells
Cell Theory
Three principles:
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All living things are made up of cells
Cell is the basic unit of structure and function
in living things
New cells arise from pre-existing cells
Common features in All Cells
Outer membrane
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separates internal from external environment
Cytoplasm
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makes up the cell interior
Ribosomes
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structures on which proteins are made
DNA
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provides instructions for making proteins,
regulates cellular activities and allows cells to
reproduce
Prokaryotic Cells
Bacteria and Cyanobacteria
Considered the simplest cellular organism
Prokaryotic Cell Structure
Distinguishing characteristics
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Enclosed in an outer membrane
No internal membrane-bound organelles
Interior is one continuous compartment
No nucleus
 DNA found in the nucleoid region
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Most prokaryotes contain a cell wall
 different composition from plant cells
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No internal support structure
 no cytoskeleton
 support comes from cell wall
Prokaryotic Cell
Eukaryotic Cells
Found in plants, animals, and fungi
Divided into three regions
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Outer membrane
Nucleus
Cytoplasm
 occupies volume between nucleus and outer
membrane
Eukaryotic Cell Structure
Distinguishing characteristics
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Interior compartmentalized
 membranous and non-membranous organelles
 each have specific functions within the cell
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Nucleus
 Membrane-bound organelle that houses the DNA
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Cell walls limited to certain types
 plant cells, some fungi
 some protists (ex. paramecium)
Think-Pair-Share
Use a Venn diagram to show how
Prokaryotic & Eukaryotic cells are
alike and how they are different.
(at least 2 concepts in each
compartment of the diagram)
Be ready to share
Eukaryotic Cell Structure (cont.)
Further classified into
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Plant cells
Animal cells
Plant Cells have unique features
Plastids
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Photosynthetic
 chloroplast is site of photosynthesis
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Non-photosynthetic
 Storage
 Ex. Potatoes - starch
Ripe fruit - pigments
Plant Cells Have Unique Features
Central Vacuole
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Storage
 Holds reserves of organic compounds
 stores byproducts that would be toxic to the cell
 Stores pigments
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Growth
 Fills with water that pushes cytoplasm against cell
wall
 If cell wall has capability to loosen, cell will expand
Plant Cells has unique features
Cell Wall
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Protects the cell
Maintains shape of cell
Plant Cell
Animal Cells Have Unique
Features
Lysosomes
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Where macromolecules are hydrolyzed
Breaks down worn out organelles
Defective lysosomes cause diseases
 Ex. Tay Sachs disease
Animal Cell
Link to Bellwork
Describe at least two important features
that are different for Bacteria and Plant
Cells.
Think-Pair-Share
Draw a simple diagram of a Plant Cell
and an Animal Cell, showing the key
features that distinguish the two
types of cell.
Be ready to share