What is a cell?
A cell is the smallest unit of an organism that can carry on
life's functions.
WHAT?
1. Cells are the building blocks of organisms.
2. Each cell must be able to do jobs to keep it alive such as growing,
developing, and using energy. They also must be able to reproduce
to make more cells.
Who discovered cells?
• There were many
scientists who were
involved in the discovery.
• Its started with Hans and
Zacharias Janssen. This
father and son team
created the first
compound ( 2 lens)
microscope.
• They however did not use
this microscope to
observe cells.
Then there was Robert Hooke in
1665
• Robert Hooke was an
English Scientists that
looked at cork under a
compound microscope.
•
No one knows what he looks like.
His portrait has not been seen since
1710.
He observed little empty
boxes that he called
CELLS because they
reminded his of rooms
where monks lived.
Hooke’s drawing of cork
Anton van Leeuwenhoek
• Had a drapery business
and would use simple
lens to examine cloth.
•He would use his lens to
examine nature.
•He noticed small living
things living in a drop of
pond water. He called
these creatures
“animalcules”.
Matthias Schleiden
• German botanist
(scientist that studies
plants) who viewed
different parts of
plants under a
microscope such as
leaves, stem, and
roots.
• He discovered that
they were made up of
cells.
Theodor Schwann
• Was a German
zoologist (scientist
that studies animals)
who views animal
parts under a
microscope and
discovered that
animals were made
up of cells.
The observations of these and many
other scientists led to the creation of the
cell theory.
The cell theory states:
1. All organisms are made up of one or
more cells.
2. The cells in all organisms have the
same basic parts and the same job to
do.
3. All cells come from cells that already
exist.
Notes:
•
Cells are the building blocks of
organisms. Each cell must be able to do
jobs to keep the organism alive.
•
Cells were first discovered by Robert
Hooke in 1665. He looked at a piece of
cork under a microscope and saw little
empty boxes which he called cells
Yeah more notes:
Cell theory is based on the findings of many
scientists. It contains three parts:
1. All organisms are made up of one or
more cells.
2. The cells in all organisms have the same
basic parts and the same job to do.
3. All cells come from cells that already exist.
There are 2 types of cells.
• Prokaryotic- Cells that
do not have a
nucleus. These are
bacteria cells.
• Eukaryotic- Cells that
do have a nucleus.
These are plant and
animal cells
Yeah I love taking notes
There are two types of cells.
1. Prokaryotic cells- are cells that do not
have a nucleus. Example- bacteria
2. Eukaryotic cells- are cells that do have a
nucleus. Example- plant and animal cells.
Cell Structures
•
Cell is made up of many parts called
organelles.
•
Organelles are like "the organs of the
cell".
Cell Wall
Found only in a plant cell.
The cell wall is a stiff and
rigid structure located on
the outside of the cell.
Gives the plant cell a
rectangular shape.
Cell wall
Cell Membrane
Cell membrane
•Found in both a plant and
animal cells.
•In a plant cell, the cell
membrane is located just
inside the cell wall.
•In an animal cell, the cell
membrane is the outer
boundary.
•Its job is to allow certain
materials to enter (oxygen,
food, water) and leave (waste)
the cell.
Cell membrane
Cytoplasm
Cytoplasm
Found in both a plant
and animal cells.
Cytoplasm is a gel-like
material that fills up
the empty space within
a cell.
It holds the other
organelles.
Cytoplasm is
constantly moving
inside the cell.
Cytoplasm
Nucleus
Found in both a plant and
animal cells.
The nucleus controls all
of the cell's activities.
nucleus
nucleus
Nuclear Membrane
Found in both a plant
and animal cells.
The nuclear membrane
separates the nucleus
from the cytoplasm.
The nuclear membrane
controls what enters
and leaves the
nucleus.
Nuclear membrane
Chromatin
Found in the nucleus of
both a plant and animal
cells.
Made up of DNA.
Chromatin contains all the
information about the
organism, such as what
type of species it is, how it
looks, and how it acts.
"blueprints of an
organism".
Chromatin
Nucleolus
Nucleolus
Found in the nucleus both a
plant and animal cells.
The nucleolus tells the
ribosomes how much and
what type of protein to
make.
It is in charge of making
proteins.
Endoplasmic Reticiulum (ER)
Found in both a plant and
animal cells.
The ER is a folded
membrane that moves
materials around inside the
cell
It extends from the nucleus
to the cell membrane.
The ER acts like a
conveyor belt for the cell.