2. 3.1 Cell Theory TEKS 3F, 4A
The cell theory grew out of the work of many scientists
and improvements in the microscope.
• Many scientists contributed to the cell theory.
• More was learned about cells
as microscopes improved.
3. 3.1 Cell Theory TEKS 3F, 4A
The cell theory grew out of the work of many scientists
and improvements in the microscope.
• Many scientists contributed to the cell theory.
• More was learned about cells
as microscopes improved.
• The cell theory is a unifying
concept of biology.
4. 3.1 Cell Theory TEKS 3F, 4A
Early studies led to the development of the cell theory.
• The Cell theory has three principles.
– All organisms are made of cells.
5. 3.1 Cell Theory TEKS 3F, 4A
Early studies led to the development of the cell theory.
• The Cell theory has three principles.
– All organisms are made of cells.
– All existing cells are produced by other living cells.
6. 3.1 Cell Theory TEKS 3F, 4A
Early studies led to the development of the cell theory.
• The Cell theory has three principles.
– All organisms are made of cells.
– All existing cells are produced by other living cells.
– The cell is the most basic unit of life.
7. Prokaryotes
Genetic material is
not in a nucleus
Less complicated
and smaller than
eukaryotic cell
Example: Bacteria
**An organism made
of a prokaryotic cell
is called a
prokaryote.
9. Eukaryotes
Genetic material is
contained in a nucleus
and separated from the
rest of the cell
More complex and
larger than prokaryotic
cells
Example: Plants,
animals, fungi, protists
**An organism made of
eukaryotic cell(s) is
called a eukaryote.
11. Eukaryotic cell structure
Two major parts:
Nucleus
Cytoplasm-portion of
the cell outside the
nucleus that contains
organelles (parts or
“organs” of the cell)
12. Nucleus-The control center
Structure:
Surrounded by a double
membrane called a
nuclear envelope. It is
dotted with many
nuclear pores to allow
materials (RNA,
proteins, etc) in and out
of the nucleus.
13. Nucleus
Function:
Contains almost all of the cell’s DNA for
coding proteins and other molecules.
DNA is found on chromosomes which contain
genetic information.
The Control Center of the cell!
16. Rough Endoplasmic Reticulum
Structure:
Membranous system
Rough ER- has ribosomes
on surface to assemble
proteins
Continuous with the
nuclear envelope
Function:
Site where lipid parts of
cell membrane are made,
along with proteins and
other materials to export
from the cell.
17. Smooth Endoplasmic Reticulum
Structure:
Membranous system
NO ribosomes on surface
Function:
Synthesis of lipids and
phospholipids for
membranes
Detoxifies drugs and toxins
in the cell
18. Golgi Apparatus
Structure:
Stack of closely
packed membranes
Function:
Modify, sort, and
package proteins and
other materials from
the ER for storage in
the cell or release
from the cell. It puts
the finishing touches
on proteins.
19. Lysosomes
Structure:
Small sac, filled with
digestive enzymes
Function:
Breakdown of lipids,
carbohydrates and proteins
into small molecules to be
used by the rest of the cell
Breakdown used up
organelles
Gets rid of all “stuff” in
the cell
The “Clean-up crew”
20. Vacuole
Structure:
Sac-like
Plant cells have one
large central vacuole
Animal cells have many
small vacuoles
Function:
Stores water, salts,
proteins and
carbohydrates
21. Mitochondria
Structure:
Enclosed by two
membranes with the
inner folded membrane,
called cristae.
Contains it’s own DNA
(Evidence for the
Endosymbiotic Theory)
Function:
Convert chemical energy
in food into materials
easier for the cell to
use. This is called cell
respiration.
22. Chloroplasts
Structure:
Surrounded by two membranes
Stacks of membranes inside
called thylakoids.
Contains own genetic
information like mitochondria
Contains green pigment called
chlorophyll
Not found in animal cells!
Function:
Captures energy from the sun
(solar energy) and changes it
into food (chemical energy) for
plants (photosynthesis).
23. In 1967, Lynn Margulis proposed that mitochondria
and chloroplasts were descended from ancient
symbiotic prokaryotes. This theory is called the
Endosymbiotic Theory!
Click on image to view video
The History of the cell continued
24. Cytoskeleton- structure and support
Structure:
Two types:
microfilaments and
microtubules- made of
proteins
Function:
Helps maintain cell
shape
Helps with movement
of the cell (i.e. flagella
and cilia)
27. Centrioles
Structure
Pair of cylindrical
arrangement of
microtubules found
perpendicularly to each
other
Region around centrioles
called centrosome
Function
help Divide the DNA in
ANIMAL CELL division
28. Cell Membrane
Structure:
Double membrane called
a lipid bilayer
Flexible structure that
forms a strong barrier
between the cell and its
surroundings
Phospholipids with
integral proteins and
cholesterol
Function:
Regulates what enters
and leaves the cell
Provides protection and
support
29. Cell Wall
Structure:
Lies outside the cell
membrane
Made of structural
carbohydrates
Found in plants, algae,
fungi and many
bacteria
NOT FOUND IN
ANIMAL CELLS!
Function:
Provides support and
protection for the cell
30. Levels of organization
(smallest to largest)
1. Cells
2. Tissues: group of similar cells with specific function
Four types: muscle, epithelial, nervous, connective tissue
3. Organs: groups of tissues working together
4. Organ systems: a group of organs that work together to perform
a specific function
Examples: Nervous system, digestive system
