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Biology is the study of .
Remember the 7 Characteristics of Life?
THE CELL
CELLS
ALL LIVING THINGS ARE COMPOSED OF CELLS
LIFE!
THE CELL/THE CITYFirst…a little history….
•A long long time ago…at the time of Aristotle (4th Century BC),
•people (including scientists) believed in something called Spontaneous Generation
•Simple living organisms could arise by SPONTANEOUS GENERATION. This was the idea that non-living objects can give rise to living organisms.
•It was common “knowledge” that simple organisms like worms, beetles, frogs, and salamanders could come from dust, mud, etc., and food left out.
BUT THEY WERE WRONG!
Because they were wrong, we need a story to clarify and explain the truth.
Once upon a time a long time ago…
…the microscope was invented.
HANS AND SON
• Sometime about the year 1590
• 2 Dutch spectacle makers, Zaccharias and Hans Janssen started experimenting with these lenses.
•They put several lenses in a tube and made a very important discovery.
•The object near the end of the tube appeared to be greatly enlarged, much larger than any simple magnifying glass could achieve by itself!
•They had just invented the compound microscope
Galileo•Galileo heard of their experiments and started experimenting on his own. •He described the principles of lenses and light rays and made improvements•He added a focusing device to his microscope and went on to explore the heavens with his telescopes.1592
•Became very interested in lenses while working in a store.
•He made rounded lenses which produced greater magnification, and his microscopes were able to magnify up to 270X
•He became more involved in science and with his new improved microscope was able to see things that no man had ever seen before.
Anton von Leeuwenhook
Anthony Leeuwenhoek (1632-1723) has since been called the "Father of Microscopy".
Robert Hooke's sketches of cork cells.
Story of Robert Hooke(1665)
• Hooke discovered plant cells
• He coined the term "cells": the boxlike cells of cork reminded him of the cells of a monastery.
• Hooke also reported seeing similar structures in wood and in other plants.
The Sad Story of Jean Baptiste Pierre Antoine de Monet
Chevalier de Lamarck(1809)
• We will just call him Lamarck
• Lamarck “Lamarcked” that “no body can have life if its constituent parts are not cellular tissue or are not formed by cellular tissue.”
• Lamarck's scientific theories were ignored and attacked during his lifetime.
• 1838 Schleiden- observed that all plants seemed to be composed of cells
• 1839 Schwaan- stated that all living things are composed of cells.
• 1858 Virchow- stated that every cell comes from a cell".
Story of other Scientists
(THINK Schliding down the tree)
(THINK Schwans are beautiful birds)
(THINK Give pregnant dog virchow)
ACTIVITY
First come up with 4 phrases to try to remember the discoveries of these men.
• ALL CELLS COME FROM OTHER CELLS
• THE CELL IS THE BASIC UNIT OF LIFE
• ALL LIVING THINGS ARE COMPOSED OF CELLS
The ending to of all this…The Cell Theory
PERSON GETS CREDITED
WITH:Leeuwenhoek
Hooke
Lamarck
Schwaan
Schleiden
Microscope
Found plant/cork cells and can up with term “cells”
All life is made of cells
Animals have cells
Plants have cells
8
Highly magnified view (2000x) of human pus showing white blood cells (called neutrophils) with deeply-lobed
purple nuclei.
A culture of rod-shaped anthrax bacteria (Bacillus anthracis). Some of the bacteria have divided by
fission (red arrow).
The Biggest cell
• By volume: An ostrich egg
– An average egg weighs about three pounds (1.4 kg)
– Roughly equivalent to about two dozen chicken eggs.
– It would take approximately 40 minutes to hard-boil an ostrich egg.
• By length: nerve cells
–Nerve cells from the spinal cord of a large mammal may be nearly two feet (0.6 m) in length.
Cell Size is Restricted
• Most cells are small
• Simple geometry more than anything else:
• Relationship between surface area to volume.
For now think of the cell as an independently functioning unit of life. In order to perform the many specific tasks there must be many specific parts. So we will
come up with an ANALOGY- The Cell as the City.
THE CELL THE CITY
•Cell membrane is like the _________________ because it determines what comes in and
of the cell/city
•The nucleus is like __________- a storage site for all the cells information.
•The cytoplasm is like the __________________ in the city. They are the substances in the cell that carry oxygen, proteins, carbs, and
other substances.
•The mitochondria is like a _____________. This is where nutrients are converted into
usable cellular energy.
•Ribosomes are the site where protein is put together. Like the __________ oF a city.
City limits, borders
City hall
Land, air, and water
Power plant
factories
•Endoplasmic reticulum are like ___________________________ because they are where the proteins, lipids, and carbohydrates (3 of the big 4) are processed
•Golgi apparatus are like the _____________________. They are the parts that modify and package up the cellular materials before being excreted out of the cell.
•Lysosomes and peroxisomes are the _______________________. They store strong digestive proteins.
Like a stack of pancakes
Lysosomes under the microscope
Assembly line/or Tax office
Post office
Waste removal/sewage plant
•Chloroplasts are analogous to ________________________ found in green plant cells and some protists. They convert sunlight into cellular energy.
•Vacuoles are like the city’s _________________. They hold water and nutrients for the cell. Large central vacuoles usually just found in plant cells
•Centrioles are like the __________________________ which aid in cell division. Found mainly in animal cells.
a solar Power plant
water tanks
traffic lights/cops directing
Cell wall is analogous to ________________________________. It is found mainly in plants and provides support to the cell.
Microtubules are like _____________________________ which conduct movement of cytoplasm and provide cellular support. They aid in movement during mitosis. Spindle fibers are microtubules.
an outside city surrounding highway
roads and train lines
LET’S TAKE A CLOSER LOOK AT SOME CELLS
A little review…
What cell parts are only present in PLANT cells?
CENTRIOLES
What cell parts are only present in ANIMAL cells?
CELL WALLS, CHLOROPLASTS AND LARGE CENTRAL VACUOLES
More reviewLET’S FILL IN THE CHART BELOW WITH 1 WORD ANSWERS.
CELL PART ONE WORD FUNCTION
CELL MEMBRANCE
GOLGI BODIES
VACUOLES
NUCLEUS
LYSOSOME
Click for answers
POSSIBLE CHART ANSWERSCELL PART ONE WORD
FUNCTION
CELL MEMBRANCE
regulator
GOLGI BODIES packager
VACUOLES storage
NUCLEUS information
LYSOSOME digestion
THE CELL IN A BAG THE CELL IN A BAG COMPETITIONCOMPETITION
•Working in groups of 4 you will create a cell in a bag
•You need to be neat with your supplies and specific with your cell parts
•Use the provided sheet to accompany your cell in a bag
•Your model should make sense in terms of size of organelles
•There is a time limit!
CELL MOVEMENT
Cells need to move. Why? Turn to your table partner and come up with 3 types
of cells and why they might need to move?
Sperm cells need to “swim to the egg” to
fertilize it!
White blood cells need to move
around the body to help fight infection!
Plant cells need to
move from one plant to another- like
pollen- so that it too
can fertilize another plant
for reproduction
How do cells move?PLANT CELLS CAN NOT MOVE ON
THEIR OWN…THEY RELY ON THEIR ENVIRONMENT TO MOVE…
EXAMPLES: air, wind, water moving cells from one place to another.JUST ANOTHER REASON WHY WE
NEED TO KEEP OUR RIVERS CLEAN AND FLOWING!
Some animal cells rely on bodily fluids to move them as well.
Animal cells move
•Cilia= many small hair like structures around the outside of the cell
•Flagella- long whip-like extensions from cell. Propeller-like.
Pseudopod- false foot extension of cell membrane
LABEL AND COLOR
THAT’S A TON OF INFO! LET’S NOW LABEL THE PARTS!
ribosomes
mitochondria
centriole
Cell membrane
Nucleus
Nucleolus
Golgi body
Endoplasmic reticulum
Lysosome or chloroplast on plant cell
Cell Wall
LET’S EXPLORE REAL CELLS
What might a cell look like under a microscope?
Will we see all the parts?
What might we see more often in plants than in animals?
A lab…
