Biological Sciences

NSC III Monday & Tuesday

10:30 to 12:00

Reporters

Joelbyn Datu

Gerlif Delgado

M o t I v a t I o n

Done

Joelbyn Datu

Gerlif Delgado

THE CELL THEORY

In 1665, an English scientist

Robert Hooke, with the aid of his own invented

Microscope was able to examine a variety of

objects including the Bark of a cork oak tree.

As he observed this, he noticed tiny, empty

compartment like the structure of a

honeycomb. He gave them Latin Van

Leeuwenhoek, the Dutch shopkeeper,

With his skills in glass working, devoted much

of his time in constructing lenses and observing everything he

could get hold of, including bacteria gliding

in saliva,

0ne - celled organisms in pond water, and even

sperm swimming in semen. With his skills and keen observations, he was able to draw

and describe the variety of tissues of living

organisms

Two centuries passed, with the aid of improved

light microscopes, scientists were tempted to look once more into

the cell. In 1833 Robert Brown, a botanist reported the presence

of a sphere

Like structure inside a plant cell and called it a nucleus. About 1839, two German scientists

worked together in examining thoroughly the cell. Matthias schleiden, a botanist, and theodor

schwann,

A Zoologist, recognized the basic similarities between plant and

animal cells. thus, in 1839, they proposed the

principles of the CELL THEORY:

All organisms are composed of one or more

cells. The cell is the basic living unit of organization

for all organisms. Cell are formed by free-

cell formation, similar to the formation of crystals.

Then, a decade passed, after exhaustive studies

into cell reproduction, German physician

Rudolf Virchow disproved the third statement and completed the cell theory

with another principle:

All cell arise from pre-existing cells.

The modern tenets of Cell Theory including:

Cells contain hereditary

information which is passed from cell

to cell during division.

All cells are basically the same in

chemical composition

All energy flow (metabolism and

biochemistry)Of life occurs within

cells.

In terms of cellular organization, cells have

two Categories:

Prokaryotic Cells

Eukaryotic Cells

Prokaryotic CellsAre of the simpliest cell type, without membrane

bound nucleus nor contain cytoplasmic organelles such as

mitochondria, plastids and golgi networks.

What they have is a cell wall, plasma membrane, cytoplasm, and nucleoid which is an irregularly shaped region where DNA concentrates, in

addition, they also contain enzymes, which

like DNA

are able to reproduce and engage in

metabolism , and ribosomes, which are

RNA – protein structures that function in protein synthesis. Bacteria are

classified as prokaryotic cells.

These organisms cause diseases like Tuberculosis

Strep Throat

GonorrheaAcne

Other types of bacteria are responsible for the decomposition of dead

organisms. In a few bacteria splices, there is

a types of green photosynthesis pigment.

Which is responsible for energy conversion of

photosynthesis and other chemical reactions in the

cells.

Eukaryotic CellsWhich make up animals,

plants, fungi and all other life forms, contain a well- defined nucleus and numerous distinct

organelles that constitute compartment

defined

By a membrane or a membrane system.

Organelle compartmentalization

allowed eukaryotic cells to become much more

specialized because each organelle carries out its

function in an

Isolated environment. Organelles have

variations in type and number among the cell

types.

Slideshare.net/JoelbynDatu

Robert Hooke

Microscope

Cork oak tree

Honeycomb

Robert Brown

Matthias Schleiden

Theodor Schwann

Rudolf Virchow

From Two Greek words meas“before” and “kernel”

Reflects their lack of a nucleus Little internal organization.

From two Greek words which Means “True” and “Nucleus”Reflects the presence of a

True nucleus.

DeoxyriboNucleic acid

Tuberculosis

Strep Throat

Gonorrhea

Acne