B.tech biotech i bls u 2.1 the cell theory

Cell Cell as basic unit of lifeas basic unit of life

Course: B.Tech BiotechSubject: Basic of Life Science

Unit: II

What is the definition of a cell?The basic unit of life.Cells Make up PlantsCells make up all living things.

Can you think of reasons why cells need nutrition and a good environment?

CellsCells represent the basic structural and represent the basic structural and functional unit of life.functional unit of life. Important unifying concept in biology.Important unifying concept in biology. All organisms are composed of one or more cells.All organisms are composed of one or more cells. All tissues & organs are composed of cells.All tissues & organs are composed of cells.

There is no life without cells!There is no life without cells!

Cells produce tissuesTissues produce organs

Organs produce organ systemsOrgans systems produce organisms

Some Random Cell FactsSome Random Cell Facts The average human being is composed The average human being is composed

of around 100 Trillion individual cells!!!of around 100 Trillion individual cells!!! It would take as many as 50 cells to It would take as many as 50 cells to

cover the area of a dot on the letter “cover the area of a dot on the letter “ ii””

WOW!!!WOW!!!

Discovery of CellsDiscovery of Cells 1665- English Scientist, 1665- English Scientist, Robert Hooke, Robert Hooke, discovered discovered

cells while looking at a thin slice of cork.cells while looking at a thin slice of cork. He described the cells as tiny boxes or a honeycombHe described the cells as tiny boxes or a honeycomb He thought that cells only existed in plants and fungiHe thought that cells only existed in plants and fungi

1.

Anton van LeuwenhoekAnton van Leuwenhoek 1673- Used a handmade microscope to observe 1673- Used a handmade microscope to observe

pond scum & discovered single-celled organismspond scum & discovered single-celled organisms He called them “animalcules”He called them “animalcules”

He also observed blood cells from fish, birds, frogs, He also observed blood cells from fish, birds, frogs, dogs, and humansdogs, and humans

Therefore, it was known that cells are found in Therefore, it was known that cells are found in animals as well as plantsanimals as well as plants

2.

= Three part theory about cells

1. All living things are made of cells. (Schleiden & Schwann)(1838-39)

2. The cell is the basic structural and functional unit of life. (Schleiden & Schwann)(1838-39)

3. All cells come from pre-existing cells. (Virchow)(1858)

Cell theory

How big are cells?

Smallest free-living cell = Mycoplasma genitalium

Size = 0.2 to 0.3 µm

3.

How big are cells?

• Bacteria e.g. Eschericia coli (aka E.coli)

• Size=1 µm by 3 µm

4.

How big are cells?

• Human red blood cell = 8 µm in diameter

5.

How big are cells?

• Largest cell on the human body =

ovum

• Size=

• 1000 µm in diameter

(1 mm) 6.

How big are cells?

• Smallest cell in the human body =

sperm cell.

7.

How big are cells?

• Largest cell = yolk of an ostrich egg

9.8.

Modern Cell TheoryModern Cell Theory Modern Cell Theory contains 4 statements, in Modern Cell Theory contains 4 statements, in

addition to the original Cell Theory:addition to the original Cell Theory: The cell contains hereditary information(DNA) which The cell contains hereditary information(DNA) which

is passed on from cell to cell during cell division.is passed on from cell to cell during cell division. All cells are basically the same in chemical All cells are basically the same in chemical

composition and metabolic activities.composition and metabolic activities. All basic chemical & physiological functions are All basic chemical & physiological functions are

carried out inside the cells.(movement, digestion,etc)carried out inside the cells.(movement, digestion,etc) Cell activity depends on the activities of sub-cellular Cell activity depends on the activities of sub-cellular

structures within the cell(organelles, nucleus, plasma structures within the cell(organelles, nucleus, plasma membrane)membrane)

How Has The Cell Theory Been Used?How Has The Cell Theory Been Used?

The basic discovered truths about cells, listed The basic discovered truths about cells, listed in the Cell Theory, are the basis for things in the Cell Theory, are the basis for things such as:such as: Disease/Health/Medical Research and Cures(AIDS, Disease/Health/Medical Research and Cures(AIDS,

Cancer, Vaccines, Cloning, Stem Cell Research, etc.)Cancer, Vaccines, Cloning, Stem Cell Research, etc.)

Common features of all cells

1. Cell Membrane – selectively/differentially permeable (lets some things in and out)

10.

Common features of all cells

2. Cytoplasm – semi-fluid material in which cell organelles float

11.

Common features of all cells

3. Nucleic acid containing genetic code :

Which nucleic acid?

DNA

12.

Common features of all cells

4. Cytoskeleton – proteins that support the cell

(Microtubules &

microfilaments)

13.

Common features of all cells

5. Ribosomes

– make proteins

14.

Some Parting ThoughtsSome Parting Thoughts It is amazing to think that the cells that make It is amazing to think that the cells that make

up our bodies are just as alive as we are. up our bodies are just as alive as we are. Humans are just an intricately designed Humans are just an intricately designed community of cells, which must work together community of cells, which must work together to survive.to survive.

Cells, in my opinion, are one of the strongest Cells, in my opinion, are one of the strongest cases for intelligent design by our Creator cases for intelligent design by our Creator God!God!

Web and Books referencesWeb and Books references Book Name : AlbertBook Name : Albert

http://en.wikipedia.org/wiki/Cell_theoryhttp://en.wikipedia.org/wiki/Cell_theory http://www.edu.pe.ca/gray/class_pages/smaccormachttp://www.edu.pe.ca/gray/class_pages/smaccormac

k/topic_2_1_celltheory.pdfk/topic_2_1_celltheory.pdf http://www.princeton.edu/~achaney/tmve/wiki100k/dohttp://www.princeton.edu/~achaney/tmve/wiki100k/do

cs/Cell_theory.htmlcs/Cell_theory.html http://www.uic.edu/classes/bios/bios100/lecturesf04ahttp://www.uic.edu/classes/bios/bios100/lecturesf04a

m/lect06.htmm/lect06.htm

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Images ReferencesImages References 1.http://3.bp.blogspot.com/NX3o3HssjkI/UEmYoopb5xI/AAAAAAAAAH1.http://3.bp.blogspot.com/NX3o3HssjkI/UEmYoopb5xI/AAAAAAAAAH

k/pE33sBBi90E/s1600/Robert+Hooke+and+the+microscope+use+to+ak/pE33sBBi90E/s1600/Robert+Hooke+and+the+microscope+use+to+analyze+cork+cell.PNGnalyze+cork+cell.PNG

2.http://www.masslocalinstitute.org/onlinecourses/publichealthhistory/va2.http://www.masslocalinstitute.org/onlinecourses/publichealthhistory/vanLeeuwenhoek.jpgnLeeuwenhoek.jpg

3.http://wishart.biology.ualberta.ca/BacMap/includes/species/Mycoplas3.http://wishart.biology.ualberta.ca/BacMap/includes/species/Mycoplasma_genitalium.pngma_genitalium.png

4.https://31.media.tumblr.com/3819bfc3e1fdc2b2f1fb1406ecf7ca5e/tum4.https://31.media.tumblr.com/3819bfc3e1fdc2b2f1fb1406ecf7ca5e/tumblr_inline_nc5kjt5EeG1t196up.gifblr_inline_nc5kjt5EeG1t196up.gif

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6. http://img.tfd.com/mk/O/X2604-O-20A.png6. http://img.tfd.com/mk/O/X2604-O-20A.png 7.http://us.cdn1.123rf.com/168nwm/lightwise/lightwise1311/lightwise137.http://us.cdn1.123rf.com/168nwm/lightwise/lightwise1311/lightwise13

1100063/23843295-human-fertility-questions-and-reproductive-health-1100063/23843295-human-fertility-questions-and-reproductive-health-confusion-and-uncertainty-as-a-male-sperm-cell-and.jpgconfusion-and-uncertainty-as-a-male-sperm-cell-and.jpg

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9.http://suzyssitcom.com/wp-content/uploads/2012/02/Ostrich-9.http://suzyssitcom.com/wp-content/uploads/2012/02/Ostrich-Egg-200x150.jpgEgg-200x150.jpg

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.png.png 13.https://encryptedtbn0.gstatic.com/images?13.https://encryptedtbn0.gstatic.com/images?

q=tbn:ANd9GcQS1FuhaOk6JfcrDPI1cugdw52uxfCMJB153xeigq=tbn:ANd9GcQS1FuhaOk6JfcrDPI1cugdw52uxfCMJB153xeigmTQVt95MHahmTQVt95MHah

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