• Botanist first to study plant cells.
• Studied animal cells first

• Plants cells made other plant cells
• Animal cells made other animal cells

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 used a crude compound microscope to view a cork and seen honey comb shapes in 1665.
He coined the term cells since they reminded him of the small box cells
Monks lived in.

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Microscopes - magnify things not visible with human eyesight alone.
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Anton Van Leeuwenhoek , used a single lens to view cells in the
1600’s.

 in the 1830’s
• viewed organisms underneath microscopes and verified that all living things are made of cells.

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Microscope
• has a series of lenses that magnifies the object in steps.
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Microscope -
• electrons are aimed in a beam through a magnetic field to focus them then, through or over a specimen in a vacuum, and finally onto a screen where it forms a image.

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Cells have to be limited in size by natural laws.
• enough to hold the essential components
• enough to accommodate nutrients received and disposed.

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Large cells have less surface volume relative to its size than small cells.
• So the bigger the cell doesn’t mean more effective.
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The smaller cells can be serviced better by the cytoplasm.

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Computer chip technology
• is similar to this natural phenomena.

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Eukaryote CELLS
(PLANT, ANIMAL, PROTIST &
FUNGI)
• range from 10 micrometers to 100 micrometers in diameter.
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PROKAROTE CELLS
(BACTERIA)
• are a lot smaller and structurally simple

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 is the first type of cell to evolve, there are NO internal organelle structures.
It has DNA and cytoplasm and most likely single celled.

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Bacterial Cells
Capsules –
• Act as cell walls
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Circular DNA
• Genetic information
 coiled DNA
• No membrane for nucleoid region.

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Prokaryotic cells
• are small and structurally simple
• Simple membrane bound cytoplasm
• DNA
• RNA

All Bacteria cells are Prokaryotes

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They can be single cell or multicellular organisms.

Eukaryote - The second type of cell formed.

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Complexity
• Organelles

Nuclei

Plants have cell walls

Large Vacuole

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Multi cellular and Unicellular types have:
• Plant - multi
• Animal - multi
• Protist – single and multi
• Fungi - single and multi

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Plasma membrane
Cytoplasm
Organelles
Nucleus

Cell Wall (only in plants)

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Eukaryotic cells have functional compartments:
NUCLEUS – Contains:
• DNA – stores genetic information
• RNA – transmits genetic information

Messenger - mRNA

Transfer – tRNA
Ribosomal - rRNA

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Ribosome - makes proteins
• Assembles amino acids into polypeptides polymers.

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Flagella – motor transport of cell (Animal &
Protists)
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Centriole– helps cell division (Animal)
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Lysosome – breaks down particles. (Animal)
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Golgi Apparatus – stores and packages
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Plasma Membrane – regulates entry in to the cell and maintains homeostasis

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Endoplasmic Reticulum
Transport passage for the cells chemicals.
Types of E.R.:
• Smooth – no ribosomes
• Rough – with ribosomes

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Mitochondrion – energy generator of the cell (battery)
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Cytoskeleton – Supports the cells structure
• Microtubule – comprises the cytoskeleton
• Microfilament - comprises the cytoskeleton

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Cell Wall – Composed of Cellulose
• Give strength and structure to plants

Vacuole - Storage

Chloroplast – Absorb sunlight for photosynthesis.

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1. All life forms are made from one or more cells.
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2. Cells only arise from pre-existing cells.
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3. The cell is the smallest form of life. Cells

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Schleiden and Schwann proposed the cell theory in 1838,
• cell biology research was forever changed.