Download Cell Theory and Cell Structure

Cell Theory and Cell
Structure
Central Questions
• Who are the scientists who contributed to the cell
theory and what did they contribute?
• What are the parts of the cell theory?
• What are the two largest groupings of cells and what
differentiates them?
How do we know that cells exist?
Before…
• People just used their eyes
(observations)
• “If I don’t see it, it
doesn’t exist!”
Seeing is Believing!
But then, someone invented the microscope!
Anton van Leeuwenhoek built one of the first microscopes in
the 1600s and saw microscopic organisms.
Then they were named…
• Robert Hooke cut a
piece of oak tree bark
called “cork”
• Used a microscope
• “They look like little
rooms!”
• “Or like a prison cell!”
• He coined the term ‘cell’
Prison Cell vs. Cork Cell
So… then many scientists started using the
microscope to look at things
And their observations made it clear that cells
were the basic units of life.
In 1838, German botanist Matthias Schleiden
studied plants…
“Ah ha! Plants are made of cells!”
In 1839, German biologist Theodor Schwann
studied animals…
“Ah ha! Animals are made of cells!”
In 1855, Dr. Rudolf Virchow tried to be
Frankenstein… but he failed.
“We can’t create our own
new cells!”
“We can only get new
cells from already
existing cells in our
body!”
Collaboration is when scientists work together
The Cell Theory
• All living things are made of
one or more cells.
• Cells are the basic units in
living things.
• New cells are produced from
existing cells.
Introduction to Cells
Cells are the basic units of organisms
Cells can only be observed under microscope
Basic types of cells:
Animal Cell
Plant Cell
Bacterial Cell
Number of Cells
Organisms may be:
• Unicellular – composed of
one cell
• Multicellular - composed of
many cells
Cells May be Prokaryotic or Eukaryotic
• Prokaryotes include bacteria & lack a
nucleus or membrane-bound structures
called organelles
• Eukaryotes include most other cells & have
a nucleus and membrane-bound organelles
(plants, fungi, & animals)
Prokaryotes
Nucleoid region contains the
DNA
•Cell membrane & cell wall
• Contain ribosomes (no
membrane) to make proteins
in their cytoplasm
Eukaryotic Cell
Contain 3 basic cell
structures:
• Nucleus
• Cell Membrane
• Cytoplasm with
organelles
Two Main Types of Eukaryotic Cells
Plant Cell
Animal Cell
Cell Structure
• There are two parts outside the cell:
- Cell Wall: hard outside covering (not in animal
cells)
- Cell Membrane: cell ‘skin’ that controls transport
in and out
Cytoplasm
• Water based goop filling the cell
• Contains organelles and many compounds
Central Questions
• Who are the scientists who contributed to the cell
theory and what did they contribute?
• What are the parts of the cell theory?
• What are the two largest groupings of cells and what
differentiates them?