Cells

1
Cells
Hairy T-cell
2
Robert Hooke observed cells in a piece of cork
the word coining the the term cell
3
spontaneous generation

• An old belief that living thing can come from
  nonliving things????

4
In 1668, Franceso Redis controlled experiment
proved that cells can only come from other living
cells
5
Cells are microscopic

• Compound light microscope
• Light passes through lenses to magnify image up
  to 1000X
• Can observe living cells

6
How big are cells?

• Put these in order of increasing size
• Proton, electron, molecule, cell, atom
• Electron, proton, atom, molecule, cell!
• red blood cell 8 µm in diameter

7
Cell Theory

• 1. All living things are made of cells.

8
Cell Theory

• 2. The cell is the basic structural and
  functional unit of life.

9
Cell Theory

• 3. All cells come from pre-existing cells.

yeast cells dividing
10
3 parts of the Cell Theory

• All living things are made of cells.
• 2. The cell is the basic structural and unit of
  life
• 3. All cells come from pre-existing cells

11
Which came first- Prokaryote cells or Eukaryotes
cells?
Pro- means before before nucleus Eu means
true- good nucleus karyote

• Eukaryotic more advanced
• Larger and more complex
• All animal and plant cells
• Wicked nucleus

• Prokaryotic less advanced
• No nucleus
• Organelles not organized
• Include the bacteria and ancient cells!

12
Which are bigger? The cells of a mouse or the
cells of a whale?

• Answer
• Neither, they are the same.
• Cells can only grow to a certain size before they
  cant function properly.
• Larger animal just has more of them.

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Common features of all cells

• 1. Cell Membrane selectively permeable (lets
  some things in and out)

14
Diffusion

• The process in which molecule will move from a
  more concentrated area to a less concentrated
  area
• Perfume spreading throughout a room
• Food coloring spreading in water

15
How does diffusion apply to cells

• If the dashed line represents a cell membrane
  then some things will enter by diffusion.
• Materials always move from an area of higher
  concentration to an area of lower concentration.

16
Diffusion of oxygen into a cell

• Why will there always be a higher concentration
  of oxygen on the outside of a cell?

The oxygen is being used up in the mitochondria
for the process of cell respiration. What other
substance might diffuse in or out of a
cell? Answer glucose, CO2, H20,nutrients
17
Plant and animal are almost the same! What is the
difference?
Cell membrane
vacuole