The document discusses the history and structure of cells, highlighting the contributions of key scientists like Robert Hooke and Anton van Leeuwenhoek in cell discovery. It details the cell theory, which states that living things are composed of cells, cells are the basic unit of life, and new cells arise from pre-existing cells. Additionally, it compares prokaryotic and eukaryotic cells, outlines the various cell organelles, and distinguishes between structures found in plant and animal cells.

2. THE CELL HISTORY
Cells vary in size, shape, and function but there are
parts and characteristics common to all of them.
Certain cells produce secretions which are used to
promote health and improve food production

4. The discovery of cells and their structures was
scientific output of the simple microscope
discovered in the 17th century by Anton Van
Leeuwenhoek and other amateur scientist.

5. Cells were discovered by Robert Hooke in 1665.
Around 1665 he observed from a thin slice of cork,
and other plant materials.

6. There he observe box-like compartments in the cork.
Hooke thought they were small rooms or cells of
old monasteries, he called this room-like structures
cells.

8. The central part of the cell, the nucleus was
discovered by Robert Brown in 1883.
In 1838, Matthias Schleiden stated that cells are unit
structures of plants, while in 1939, Theodor
Schwaan, a zoologist said that cells are unit
structures of animals.

9. MATTHIAS THEODOR
SCHLEIDEN SCHWAAN

10. THE CELL THEORY

11. In the late 1830’s two German scientist Matthias
Schleiden, a plant biologist, and Theodore Schwaan
an animal biologist, worked on various organism-
Schleiden on plants, and Schwaan on animals.
Published in 1838 an 1839 respectively, Their dual
findings contained the first clear definition of the
cell theory.

12. MATTHIAS THEODOR
SCHLEIDEN SCHWAAN

13. In 1858, Rudolf Virchrow, a Viennese pathologist
argued that cells were capable of independent
existence. Virchrow added that new cells arise only
from pre-existing cells . This is the theory of
biogenesis which is opposed to the theory of
spontaneous generation.
Biogenesis holds that under present conditions on
earth, life can only came from life.

14. “new cells arise
only from pre-existing
cells”

15. The words of Virchrow, Schleiden and Schwaan and
a host of other scientists helped form the so-called
cell theory. The major priciples contained in the
cell theory are the following.
1. Living things are composed of one or more units
called cells.
2. Cells are capable of independent existence
3. New cells on arise from pre-existing cells.

16. PROKARYOTIC VS. EUKARYOTIC
Eukaryotic cells-
a distinct nucleus enclosed by a membrane, except
for RBC and plant cells like vessels, tracheid and
phloem elements w/c when matured also lack
nucleus and cytoplasm, eukaryotic cell make up
most of an organisms body such as amoeba and
paramecium.

17. Prokaryotic cells-
well-defined, membrane-enclosed nucleus and
organelles such are called prokaryotic

18. EUKARYOTIC CELL

19. Prokaryotic Eukaryotic
No Nucleus w/ Nucleus
No membrane-enclosed
organelles
w/ membrane-enclosed
organelles
Have one chromosomes Have chromosomes in pairs
Have no cellulose in cell walls Have cellulose in cell walls
Have smaller Ribosomes Have larger Ribosomes
No movement of cellular
materials w/in the cell
Cellular materials often appears
to move (streaming) w/in the cell
Have simple cytoskeleton Have Cytoskeleton
Have solid Flagella Have complex tubular Flagella
Do not undergo cell division Undergoes cell division by
mitosis

20. THE COMMON CELL ORGANELLES

21. A cell is enveloped in a special barrier. In
animals it is a cellular membrane, while in plants it
is a cell wall that keeps all the cells and its intricate
system of working parts intact. Biologist call these
cellular parts as organelles

22. CELL ORGANELLES FOUND IN BOTH PLANT &
ANIMAL CELLS
Cell Organelles
Cell membrane-
The first line of an animal cell is its cell membrane.
Cell membrane is made up of a double layer of fat
molecules.
Nucleus(plural, nuclei)-
The nucleus is the control center of the cell. It acts
like the brain of the cell. The nucleus is a spherical body
in the cell that acts as its control center.

23. Cytoplasm-
all organelles outside the nucleus are embedded in
the cytoplasm, a viscous jelly-like substance.
Endoplasmic Reticulum (ER)-
Endoplasm means “w/in the cytoplasm” and
reticulum means “little net”
There are two types of Endoplasmic Reticulum,
the Rough ER and the Smooth ER

25. TWO TYPES OF ENDOPLASMIC RETICULUM
Smooth ER-
the smooth ER is a network of folded and
convoluted tubules located near the nucleus. It contains
molecules called enzymes that synthesize some
hormones and estrogen.
Rough ER-
The Rough ER is also a network of folded and
convoluted sacs, its rough appearance is attributed to
the ribosomes that stud the folded structures emanating
from the nuclear membrane.

26. Golgi apparatus (pronounced “goal-gee”)-
the Golgi apparatus looks like a stack of pancakes
located near the nucleus. It function as the packaging
and distribution center of the cell.
Mitochondrion (plural, mitochondria)-
the mitochondrion is referred as the “powerhouse
of the cell”
It has outer and inner membrane and a distinctive
elongated shape similar to a hotdog.
Ribosome-
The ribosome is a small organelle packed with
RNA. It is the site of protein synthesis. The rough ER is
studded with ribosome.

27. CELL ORGANELLES FOUND IN AN ANIMAL CELL
BUT NOT IN A PLANT CELL
Lysosome-
Lysosome are circular vesicles that contain
digestive enzymes. Their main job seems to be, to eat!
The lysosomes digest not only cell nutrients but also
break down cellular waste into smaller molecules w/c
the cell can use.
Centriole-
centrioles are a branch of microtubules arranged at
right angle to each other.
Cilia or flagella (singular, cilium, flagellum)-
The cilium and flagellum are used as means of
locomotion or travel of unicellularorganisms.

28. Vacuoles-
The Vacuoles in an animal cell are the smallest in
size and more in number than that found in a plant cell.
Vacuoles act as storage areas of cell nutrients.

29. CELL ORGANELLES FOUND IN PLANT CELLS BUT
NOT IN ANIMAL CELLS
Cell Organelles
Cell wall-
aside from a cell membrane, a plant cell is
surrounded by rigid cell wall made of cellulose. The
plant cell wall protect the cell and allows it to take in
nutrients and expel waste materials.
to produce
Chloroplast-
Plants are able to produce food by converting
carbon dioxide from the air, and water into
carbohydrates. The process is powered by the energy
from the sun and is called photosynthesis.

30. Cell sap Vacuole-
in each plant cell there is one large vacuole called
the cell sap vacuole that acts as a centralized storage of
water.

31. /SUMMARY/
 Robert Hooke was the first to see a cell and the name
“cell” to the building block of living organism.
 Anton Van Leeuwenhoek is known as the “Father of
Microscopy”. His model of the microscope paved the
way the study of microscopic organism. He was the
first to see a bacteria.
 The cell is the basic unit of life. It was an outer
covering (cell wall for plant cells and cell membrane
for animal cells), a central control (nucleus), and
servicing parts (organelles).