Cells

1
Cells
2
Cells Pre-Assessment

• Make a list of 3 things you KNOW about cells
• Make a list of 3 things you WANT to know about
  cells
• Make a list of 3 QUESTIONS you have about cells
• Discuss.

3
The Cell Theory Discovery
4
Robert Hooke

• English physicist
• 1665 - used one of the first light microscopes to
  look at thin slices of plant tissues ?a slice of
  CORK
• Called thousands of tiny chambers cells,
  because they reminded him of a monasterys tiny
  rooms.

5
Anton van Leeuwenhoek

• Dutch businessman
• One of the first people to use a simple
  microscope to study nature.
• 1674 - observed living things in pond water and
  made detailed drawings of each kind of organism.
  
• He called these organisms animalcules.

6
Robert Brown

• Looked at orchid cells (1833)
• 1st to identify the nucleus of cells

7
The Final Three

• 1838 Mathias Schlieden found that all Plants
  are made of
• cells.
• 1839 Theodore Schwann found that Animals are
  also made up of cells
• 1855 Rudolf Virchow found that Where a cell
  exists, there must have been a preexisting
  cell. or cells come from cells

8
The Cell Theory

• In 1855, a number of scientists put together a
  theory about cells
• All living things are composed of Cells.
• Cells are the basic unit of structure and
  function in living things.
• New cells are produced from existing cells (Cell
  division)

9
Modern Cell Theory

• 4. The cell carries out biochemical processes
• 5. DNA is passed from cell to cell controlling
  heredity
• 6. All cells have similar chemical composition

10
Basic Cell Structures

• Cell Membrane semi permeable phospholipid
  bilayer monitors what enters and exits the cell
• Nucleus- a large structure that contains the
  cells genetic material and controls the cells
  activities
• Cytoplasm- material inside the cell membranebut
  not including the nucleus
• The semi-fluid substance that fills the cytoplasm
  is called the cytosol

11
Basic Structures
Cell Membrane
Cytoplasm
Nucleus
12
Test Your Knowledge
Fill in this Venn Diagram using your knowledge
and the picture of the two types of cells.
Prokaryote
Eukaryote
13
Prokaryote vs. Eukaryote

• Prokaryote - have cell membranes and cytoplasm
  but do not contain nuclei.
• Simple Cells
• Must have ribosomes may have flagella, cell wall
• All bacteria are prokaryotes.
• Eukaryote- Contain nuclei. Also have a cell
  membrane, cytoplasm, and specialized organelles.
• Complex Cells
• All plants, animals, fungi, and many
  microorganisms, are eukaryotes.
• Eukaryote cells are much larger than prokaryote
  cells

14
(No Transcript)
15
Prokaryote

• No nucleus
• Simple Cells
• Smaller

• Cell Membrane
• Cytoplasm
• Ribosomes

• Nucleus
• Complex Cells
• Specialized Organelles
• Larger

Eukaryote
16
So Where did these Eukaryotes come from?

• Dr. Lynn Margulis
• Mitochondria and Chloroplasts contain their own
  DNA genetic information separate from the cells
  DNA.
• So, Scientists have done research and come up
  with a Theory
• The ENDOSYMBIONT THEORY

Lets take a look at this evolution
17
The Endosymbiosis Theory

• The first eukaryotes may have formed from one
  bacteria engulfing another without killing it.
• Later a symbiotic relationship was formed

18
Diversity of Life

• Unicellular organisms- A single-celled organism
• Unicellular organisms include both prokaryotes
  and eukaryotes.

Contractile Vacuole
A prokaryotic unicellular organism
A eukaryotic unicellular organism (paramecium)
19
Diversity of Life Continued

• Multicellular organisms- organisms that have more
  than one cell working together. Have cell
  specialization
• Cell specialization- specific roles for different
  types of cells
• Segments of DNA are turned on by hormones,
  chemicals in the body during development causing
  cells to specialize

20
Levels of Organization

• Cells- the basic unit of life
• Tissues- a group of similar cells that perform a
  particular function
• Organs- many groups of tissues work together
• Organ Systems- A group of organs that work
  together to perform a specific function
• Organism- An entire living being made up of organ
  systems

21
Test your Knowledge
?
?
?
?
22
And the Answer is
23
CP Essential Question Writing Cells

• A researcher finds a cell-like structure from a
  probe sent on a mission to Mars. The cell like
  structure can make protein, has a cell wall and
  converts water and carbon dioxide into sugar
  using light energy, releasing oxygen. Inside the
  cell researchers find a nucleus, chloroplasts
  and ribosomes. The cell is observed to reproduce
  exact copy cells with the same DNA.
• What type of cell on earth is the Mars cell-like
  structure most like (prokaryote or
  eukaryote/plant or animal)? Why?
• Based on the cell theory, would the Mars
  cell-like structure be considered living? Why or
  why not?