Download Cell Theory and the Cell

Chapter 7:
The Microscope and Cell
Theory
Try these websites for fun!
• http://learn.genetics.utah.edu/content
/begin/cells/insideacell/
• http://www.sheppardsoftware.com/healt
h/anatomy/cell/cell_game.htm
Cell Theory
•
•
Then
Term “cell” was coined in
1665 by Robert Hooke
when he looked at a slice
of dried cork.
Cell Theory
1. All living things are made
of cells.
2. Cells are the smallest
“living” unit
3. All cells came from
previously existing cells.
Now
2 main types of cells
• Prokaryotic
– Lack membrane
enclosed
organelles
– Lack a nucleus
– Only Unicellular
– Bacteria
• Eukaryotic
– Have membrane
bound organelles
– Have a nucleus
– Can be unicellular or
multicellular
– Plant and Animal Cells
– 10 Times Larger than
Prokaryote Cells.
What each cell has:
• Prokaryote
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DNA
Plasma Membrane
Ribosomes
Cell Wall
Cytoplasm
Cilia/flagella
• Eukaryote
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–
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Nucleus w/ DNA
Plasma membrane
Ribosomes
Cell wall (plant)
Cytoplasm
Endoplasmic Reticulum
Mitochondria
Golgi apparatus
Large vacuole (plant)
Chloroplast (plant)
Lysosome (animal)
Cilia/flagella (animal)
Microscopes
• In the 1600’s the first
microscope was invented.
• Microscopes magnify objects
• Two main types of microscopes
– Compound light microscope
• Multiply lenses to find out
magnification
• Magnifies about 1500 times
– Electron microscope
• Uses a beam of electrons to magnify
structures
• Up to 500,000 times magnified!!!!
Anton van Leeuwenhoek
Microscope parts
eye piece
tube
nosepiece
arm
10x objective
40x objective
100x objective
stage
stage clips
rough adjustment
diaphragm
fine adjustment
Light/mirror
base
Plasma (cell)
Membrane
• Physical & chemical boundary of all cells
• A double layer called the phospholipid
bilayer.
– It is selectively permeable (semipermeable)
meaning only certain things are let in and out
• Gate-keeper of cell
Function of Proteins in Membrane
1. Transport Proteins- move large things in
and out of cell
Ribosomes
• Sites of protein synthesis
– Proteins are the main
product produced by the
cell
• Not considered a
membrane-bound organelle
so they are found in
prokaryotes and eukaryotes
Nucleus
• Control center of cell (controls
all cellular activites)
– Contains DNA
– Contains nucleolus where
ribosomes are made
Nucleolus
• Located inside
of the nucleus
• Contains RNA
and proteins
• Makes
ribosomes
Nuclear membrane/ Nuclear
envelope
• The double-layered
membrane enclosing the
nucleus of a cell.
Endoplasmic reticulum
•
Transport system of cell (transports materials)
– Rough Endoplasmic reticulum (RER) has
ribosomes
– Smooth Endoplasmic reticulum (SER) for lipid
synthesis and storage
Golgi Apparatus
• Involved in packaging and secretion of proteins
– The cellular post office
– Also called golgi body
Mitochondria
• Where energy for the cell is made (ATP)
• Site of cellular respiration
Adenosine Tri Phosphate (ATP)
Lysosomes
• Found in animal cells
– Digest and recycle worn out cell parts
– Destroy foreign invaders
Plant cell only
• Large vacuoles for storage of
water and sugars
• Cell wall made of cellulose for
support and protection
• Chloroplasts
– Where photosynthesis happens
(glucose is made from water,
CO2, & sunlight)
– Give green color
Two organelles have their own
DNA
• Mitochondria and Chloroplasts have
their own DNA because they were
probably once free-living bacteria that
were “eaten” by a larger cell and instead
of being digested, they became part of
that cell as an organelle