CellsCells: The Basic Units : The Basic Units of lifeof life

IntroductionIntroduction

What If…?What If…?Imagine this scene from a Imagine this scene from a horror film. A young man horror film. A young man sits down to dinner to find sits down to dinner to find that his mother has made that his mother has made

asparagus again. The asparagus again. The young man eats the young man eats the

asparagus stalks. Later asparagus stalks. Later he finds out that instead he finds out that instead of being digested, one of of being digested, one of the stalks has taken up the stalks has taken up

residence inside his body residence inside his body and is very much alive! and is very much alive! Too horrifying to think Too horrifying to think

about?about?

What if the asparagus began to do What if the asparagus began to do wonderful things for the young wonderful things for the young man, such as giving him more man, such as giving him more energy than he ever dreamed energy than he ever dreamed possible? Lynn Margulis, a possible? Lynn Margulis, a scientist thinks that something scientist thinks that something similar may have happened to similar may have happened to certain one celled organisms certain one celled organisms that lived more than a billion that lived more than a billion years ago, giving rise to the years ago, giving rise to the kinds of cells that we are made kinds of cells that we are made of today.of today.

According to Margulis’s theory, about According to Margulis’s theory, about 1.2 billion years ago, some larger 1.2 billion years ago, some larger cells began eating smaller cells for cells began eating smaller cells for dinner. Like the white blood cells in dinner. Like the white blood cells in your body, these larger cells trapped your body, these larger cells trapped the smaller cells with extensions of the smaller cells with extensions of their cell body. But some of these their cell body. But some of these smaller cells resisted being digested. smaller cells resisted being digested. In fact, they began to do very well in In fact, they began to do very well in their new homes. The larger cells their new homes. The larger cells also benefited from their new guests. also benefited from their new guests. The smaller cells released large The smaller cells released large amounts of energy from food taken in amounts of energy from food taken in by the larger cells.by the larger cells.

Other kinds of small cells used the Other kinds of small cells used the energy in sunlight to make energy in sunlight to make enough food to feed themselves enough food to feed themselves and the larger cell. The energy and the larger cell. The energy producing structures of most producing structures of most cells, including yours, are cells, including yours, are thought to have descended from thought to have descended from these smaller cells.these smaller cells.

The energy producing structures The energy producing structures referred to are mitochondria and referred to are mitochondria and in plants chlorophyll. One in plants chlorophyll. One reason scientists believe that reason scientists believe that mitochondria were once mitochondria were once separate organisms is that they separate organisms is that they are not coded for in our genes. are not coded for in our genes. Though they live within our cells, Though they live within our cells, they have their own genetic they have their own genetic material and independently material and independently make 90% of the proteins they make 90% of the proteins they need to function.need to function.

If mitochondria are not coded for If mitochondria are not coded for in our DNA, how do we get them. in our DNA, how do we get them. They exist in the cytoplasm of They exist in the cytoplasm of egg cells and so are passed to us egg cells and so are passed to us by our mothers. They multiply by our mothers. They multiply independently within our cells, independently within our cells, so that as our cells divide, so that as our cells divide, mitochondria are available in the mitochondria are available in the cytoplasm of the new cells. With cytoplasm of the new cells. With the exception of red blood cells, the exception of red blood cells, mitochondria exist in every cell mitochondria exist in every cell in our body.in our body.

Related questions:Related questions:

• Where is it proposed that mitochondria Where is it proposed that mitochondria came from.came from.

• Give 2 reasons which support this theory.Give 2 reasons which support this theory.• Which sex would be easier to clone. Why?Which sex would be easier to clone. Why?• What is the only cell in our body that does What is the only cell in our body that does

not have mitochondria? How might this not have mitochondria? How might this effect these cells?effect these cells?

• The process of one organism living off The process of one organism living off another in a way that benefits both is called another in a way that benefits both is called symbiosis. Name some other examples of symbiosis. Name some other examples of symbiosis.symbiosis.

• In what tissues might you find the most In what tissues might you find the most mitochondria? The least?mitochondria? The least?

Homework assignmentsHmwk. - Quiz - on Friday 12/8

Essay - due on Monday. 12/11

Write a 1 pg. Single spaced science fiction story about an animal whose cells are invaded by chloroplasts (the organelles in plants that contain chlorophyll. Describe how the animals life processes would be affected and how that animal would use this unusual occurrence to its advantage. Choose to write about a mammal, fish, bivalve, bird, reptile, insect, etc.

Attached to the essay should be a 3 sentence or longer quote from any reference on what chlorophyll is and does. Be sure to write who the author is and where you got the information. Do this first.

The Organization of LifeThe Organization of Life

• C______• T______• O______• O_____________• O_____________

                         

cells

tissues

organ

Organ System

Organism

Cells

Cells are the _______________________.

A single cell has __________________________________________________________________

Some organisms are made up of only one cell

Humans have approximately 100 trillion cells. Though each starts as 1 and after many divisions reaches 100 trillion

100,000,000,000,000

Humans have about 200 different types of cells

Name Some More!Skin Epithelial Cells

Tongue skeletal muscle& excretory glands

Thyroid cells

Tissues

• A tissue is ___________________________

______________________________________.• Some examples are – red blood cells, fat,

and muscle

Organs1) ______________________

____________________________________________

2) Examples in animals?

3) Examples in plants?

4) What is the largest organ in the human body?

5) What are three organs that help clean the blood?

6) Which organ keeps us from swelling up like a sponge when we jump in the swimming pool?

What are some plant organs?

Stamen, pistol, leaves, needles, etc.

Organ Systems

• ___________________________________________________

• Name some that humans have. What do they do?

• Name some that other animals

have like bats and dolphins

Cells & Organism

Name the Systems What do they do?

Organisms

– Organisms- _________________________

– Unicellular – _____________. ie. –amoeba or paramecium

– Multicellular – _______________________

_____________________________ as part of the group and would usually die if removed from the group

Organism Interactions

Population – a group of organisms that are _________

____________________________________________

Communities – ________________________________

____________________________________________

Ecosystems- _________________________________

________________, such as water, light, soil and rocks

-terrestrial – on land – forests, deserts, prairies, your backyard

-aquatic – rivers, ponds, lakes, oceans and even an aquarium

The Organization of Life

Cells

Anton van LeewenhoekMaybe Dutch’s grinder of lenses and

producer of glasses Zacharias Jansen was the first to construct a microscope about 1590. He used convex lenses.

Italian astronomer Anthony van Leewenhoek, also a Dutch merchant with clothes from Delf, contributed sinificantly to improving the primitive equipment. His hobby was blowing glass and fine work with metal. He grinded lenses accurately and constructed them to produce strong enlargement effects. Thanks to his microscope he could watch a structure of fibers from the clothes which he was selling. Later he started to watch leaves, flowers and small organisms like bees or lice. He also studied human blood, skin and hair. He was the first in the world to see and describe blood’s cells.

Van Leeuwenhoek (1632-1723)

•The Leewenhoek microscope was simplicity in itself. It had a single lens mounted on a metal plate with screws to move the specimen across the field of view and to focus its image. The lens was the key and permitted magnification of 70 to 270.

• In 1665 English physician and chemist Robert Hooke invented the so called compound microscope with more lenses. He watched thin small plates of cork, which was an often used material in the shipping industry. He was the first to accurately describe cells as living parts of living things.

Given the following how do you think the people below reacted to

this discovery?

• Laypeople

• Religious leaders

• Kings

• Other scientists

Before the seventeenth century, no one knew that Cells existed.

Most Cells are too small to be seen with the unaided eye.

Cells were not discovered until after the invention of the microscope in the early seventeenth century.

• Shortly after publication of Dialogue Concerning the Two Chief Systems of the World - Ptolemaic and Copernican the Inquisition banned its sale and ordered Galileo to appear in Rome before them. Illness prevented him from travelling to Rome until 1633. Galileo's accusation at the trial which followed was that he had breached the conditions laid down by the Inquisition in 1616. However a different version of this decision was produced at the trial rather than the one Galileo had been given at the time. The truth of the Copernican theory was not an issue therefore; it was taken as a fact at the trial that this theory was false. This was logical, of course, since the judgement of 1616 had declared it totally false.

• Found guilty, Galileo was condemned to lifelong imprisonment, but the sentence was carried out somewhat sympathetically and it amounted to house arrest rather than a prison sentence

• It was a sad end for so great a man to die condemned of heresy. His will indicated that he wished to be buried beside his father in the family tomb in the Basilica of Santa Croce but his relatives feared, quite rightly, that this would provoke opposition from the Church. His body was concealed and only placed in a fine tomb in the church in 1737 by the civil authorities against the wishes of many in the Church. On 31 October 1992, 350 years after Galileo's death, Pope John Paul II gave an address on behalf of the Catholic Church in which he admitted that errors had been made by the theological advisors in the case of Galileo. He declared the Galileo case closed, but he did not admit that the Church was wrong to convict Galileo on a charge of heresy because of his belief that the Earth rotates round the sun.

How do lenses work?

• Refraction – _________________ when it passes through different mediums.

• Think of a fish bowl or a glass of water

Preparing a slide (Wet mount)

Use lens paper to clean a glass slide and a coverslip.Place your specimen on the center of the slide.Place one drop of water onto the speimen (use medicine

dropper).Hold the coverslip at the edge of the water at a 45 degree

angle to the slide.Lower the coverslip slowly to avoid trapping air bubbles.If specimen starts to dry add another drop of water at the

edge of the cover slip and blot dry with a paper towel.Do the same if you wish to add stain

Utilizing the Microscope1) Always begin with the low power objective in line with the body tube2) Place slide on the stage3) Modify amount of light with diaphragm4) Lower the objective lens down close to the slide (Never let it touch)5) Turn the coarse adjustment to raise the low power objective until

the image is in focus6) Use the fine adjustment to sharpen the focus7) Position image directly in the center of the field8) Switch to the next highest objective lens9) If you goto the highest objective lens do not use the coarse

adjustment EVER.10) When done remove the slide first

• http://micro.magnet.fsu.edu/primer/java/scienceopticsu/powersof10/index.html

Onion Slides

Muscle Cells

Pond Water Slides

• Eubacterium

• Amoeba

• Rotifer

• Hydra

• Paramecium

• http://www.microscopy-uk.org.uk/index.html?http://www.microscopy-uk.org.uk/pond/

The Cell Theory

Written 200 years after Hooke’s and Leewenhoek’s discoveries by Schwann, Virchow, and Schleiden

1) All organisms are ___________________

___________________________________

2) The cell is the ______________________

___________________________________

3) All cells come from __________________

Cell Similarities

All Cells Have:• Cell membrane – the cell membrane acts as a

barrier between the inside of the cell and the cells environment. It also controls the passage of materials into and out of the cell.

• Hereditary material – every new cell receives a copy of the old cells DNA

• Cytoplasm – the fluid inside a cell and everything in the fluid is collectively known as cytoplasm.

• Organelles – functional structures inside the cell note: Not all cells have the same organelles

• Do you know any that vary from cell to cell?

ATTACK OF THE GIANT CELL

Indescribable... indestructible... Insatiable It crawls.... It creeps.... It eats you alive!

Why aren’t there giant Amoebas waiting outside of schools to

engulf unsuspecting children?

Help! I’m being eaten by

a giant cell

The lysosomes are digesting me.

Surface to Volume Ratio?

Cell Size is Limited

Cells cannot get much larger because the food and waste demands of the cytoplasm rapidly outpaces the ability of the cell membrane to transport these products based upon the surface to volume ratio.

The benefit of multicellular organisms • _______________________________________________• _______________________________________________• _______________________________________________• _______________________________________________• _______________________________________________• _______________________________________________

Why Can’t Cells Get That Big?(Surface area to Volume Ratios)

1) ________________

__________________

2) _________________

__________________

3) _________________

___________________

http://kingtet.com/theblob.htm

The Blob Theme Song

Starring Steve McQueen

2 types of cells

• Prokaryotic – ________________________ (AKA bacteria)

• Eukaryotic – __________________________

Prokaryotes

• DNA is one _________________________• ___________________________ except

ribosomes which produce proteins• These bacteria were likely the first type of cells on

Earth

Weird Science

In 1969, the Apollo 12 crew retrieved a space probe from the moon that had been launched nearly three years earlier. In the probe’s camera, NASA scientists found a stowaway. The bacterium Streptococcus mitis had traveled to the moon and back. Despite the rigors of space travel, more than 2 ½ years of radiation exposure and freezing temperatures, the Streptococcus mitis was was successfully reconstituted.

Eukaryotes

• Cells are ______________________________________• Consists of ____________________________________• ______________________________________________• Has __________________________________________• Has __________________________________________• Has __________________________________________

Cell Organelles* in the eukaryotic cell

Cell membrane• All cells ______________________• ____________________ – keeps cytoplasm in,

allows nutrients in and wastes out• _____________________________

Cell Wall

• Found only in ______________________

___________________________________

• __________________________________

___________________________________

• Because of the combined strength of billions of cell walls, _________________ hundreds of feet tall without collapsing.

Nucleus

• Only found in ________________• The cell’s ___________________• Also covered by _______________• Stores _______________ – instructions for

making proteins• Nucleolus- found _______________. It stores

the material to make ______________• note: red blood cells are the only human cells

without a nucleus or mitochondria. Thus they cannot reproduce. Lifespan 120 days.

Ribosomes

• Hook together amino acids to _____________

• The only organelles not covered by a membrane

Endoplasmic Reticulum

• The cell’s _____________________

• Makes lipids

• Moves substances through its many tubular connections

• 2 types– Rough – covered by __________________– Smooth

Mitochondria

• The cell’s _______________________• Makes _____________ – the _______________ molecule• 2 membranes

– Outer – goes around the outside– Inner – many folds – where ATP is madeRequire___________ to work – you breathe so that you’re mitochondria

can have oxygen. How long can you hold your breathe before passing out. That’s how

important mitochondria are.

Chloroplasts

• Found only __________________• Contains ____________which converts

__________________ into ______ in the presence of ____________. The sugar is used by the plant’s mitochondria to make ATP.

Where did mitochondria and chloroplasts come from?

• Many scientists believe that they used to be prokaryotic cells that were eaten by larger cells.– Mitochondria and chloroplasts are about the

_________________________________– Both are surrounded by ______________. (The

original and the new one that was formed during the engulfing process)

– Both have the same kind of ______________

______________________________________– mitochondria are _____________ in our DNA

According to Margulis’s theory, about 1.2 billion years ago, some larger cells began eating smaller cells for dinner. Like the white blood cells in your body, these larger cells trapped the smaller cells with extensions of their cell body. But some of these smaller cells resisted being digested. In fact, they began to do very well in their new homes. The larger cells also benefited from their new guests. The smaller cells released large amounts of energy from food taken in by the larger cells.

Golgi Complex

• The cell’s ______________________• _________________ are delivered here from

the ER where they ______________ for different purposes. As these items exit the golgi complex, they are enclosed in a small compartment pinched off of the golgi complex. This compartment travels to other parts of the cell or outside the cell for delivery of it’s contents.

Vesicles

• Membrane covered compartments containing ______________________

Vacuoles

• Found primarily _________________

• A large membrane covered chamber filled _______________________

• They often occupy large portions of the cell

• When the vacuoles empty, the plant wilts

Goodness Grapeness

• The vacuoles in grapes hold so much juice that they must dry in the sun for several weeks before they become raisins; losing ¾ of their original weight in the process.

Lysosomes

• _____________________________

• Found in animal cells they contain digestive enzymes.

• Responsible for the elimination of a tadpoles tail and the webbing in a fetus’ fingers.

• Their destructive power may also be part of the reason we age.

Plant vs. Animal Cells

• Awesome site with lots of info on cells

• http://www.sirinet.net/~jgjohnso/cell.html