Transcript Intro to Cell

Discovery of the Cell and Cell
Theory
Observations of Dead Cells
• Robert Hooke (16351703)
– First to view cells
(dead cork cells)
– Thought that the “little
boxes” looked like the
rooms where monks
lived (cells)
Observations of Living Cells
• Anton van
Leeuwenhoek (16321723)
– First to observe living
cells
Observations of Living Cells
cont.
• Matthias Schleiden (18041881)
– Concluded that all plants were
made of cells
Observations of Living Cells
cont.
• Theodor Schwann (1810-1882)
– Concluded that all animals were made of
cells
Observations of Living Cells
cont.
• Rudolf Virchow (1821-1902)
– Determined that cells only come
from other cells
The Cell Theory (putting the
observations together)
1. All living things are composed of one or
more cells.
2. Cells are the basic units of structure and
function in an organism.
3. Cells come only from the reproduction of
existing cells.
What did Microscopes help
scientists discover about all living
things?
• Look back at your acrostic poem, your
handout from yesterday, and your handout
from last Monday. Otherwise use your
textbook:
• Describe how Cell Theory was
developed by what scientists had
discovered thanks to microscopes
All Things are made of Cells!
• As microscopes got more complex, even
small cells and single celled organisms
could be studied.
• With this came the discovery of
prokaryotes vs eukaryotes.
• Pro-before
• Karyote-kernel or nut
• Eu-true or good
Eukaryotic Vs Prokaryotic
In your notes, write down what you see as the
difference between the 2 cells.
Eukaryotic Cell
Prokaryotic Cell
• All cells fall into one of two categories:
prokaryotic or eukaryotic
• Prokaryotic cells evolved earlier in history
than eukaryotic cells
• Prokaryotic cells lack several of the
features found in eukaryotic cells
• You are eukaryotic.
– Your cells have a nucleus and
membrane-bound organelles.
Prokaryotes
Eukaryotes
Prokaryotic vs. Eukaryotic cont.
Prokaryotic Cell Eukaryotic Cell
Cell Membrane
May be unicellular
May be multicellular
Has membranebound organelles
Has a membranebound nucleus
Contains DNA or
other genetic info
How are Prokaryotes and
Eukaryotes Different?
• Look over your notes and describe the
differences between a prokaryote and
eukaryote.
• How does knowing the root of the word
help you to describe this difference?
Intro to Cell Structure
• Quick Review:
– Cells = basic unit of life
– Unicellular: the organism is just one cell
– Multicellular: the organism has lots of cells,
each carries out a specific job
• All cells have:
– Cell membrane
– Cytoplasm (with organelles)
– DNA (genetic material)
Cell membrane
• Thin barrier separating the cytoplasm
and contents of the cell from the
external environment.
• In some cells the membrane is surrounded
by a cell wall.
– The cell wall is a thick, rigid structure
surrounding plant and bacteria cells.
Inside a Cell
• Cytoplasm
– space inside the cell, between the membrane and
nucleus that contains a semi-liquid substance and
houses the organelles.
• Nucleus
– spherical organelle that contains the DNA of
eukaryotic cells.
• Visible in most cells under a light microscope
• All plant and animal cells are eukaryotic.
• Organelles =
– specialized structures that carry out cell functions
• Most are not visible using only a light microscope
Finish your Microscope poster for
tomorrow
• Come ready to take a test.
• Bring your Green Lab Manual, and read
over Lab 6.
Onion Cells
Elodea Cells
Cheek Cells