The basic unit of life is the cell. All living things are composed of cells, which are the basic units of structure and function. Cells come in two main types - prokaryotic cells, which lack a nucleus and membrane-bound organelles, and eukaryotic cells, which have a nucleus enclosed within membranes and other membrane-bound structures. Cells vary greatly in their size, shape, and internal structures, depending on their function in different living things.

1. The Cell
The basic unit of life

2. TAKS

Objective 2 – The student will
demonstrate an understanding of
living systems and the environment.

3. TEKS Science Concepts


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B4 - The student knows that cells are the basic structures of all
living things and have specialized parts that perform specific
functions, and that viruses are different from cells and have
different properties and functions. The student is expected to:
(A) identify the parts of prokaryotic and eukaryotic cells
B3 - The student uses critical thinking and scientific problem
solving to make informed decisions. The student is expected to:
(F) research and describe the history of biology and
contributions of scientists.

4. Engage: Cell History

Cytology- study of cells

1665 English Scientist
Robert Hooke

Used a microscope to
examine cork (plant)

Hooke called what he saw
"Cells"

5. Cell History

Robert Brown


Matthias Schleiden




discovered the nucleus in
1833.
German Botanist
Matthias Schleiden
1838
ALL PLANTS "ARE
COMPOSED OF
CELLS".
Theodor Schwann


Also in 1838,
discovered that animals
were made of cells

6. Cell History

Rudolf Virchow



1855, German Physician
" THAT CELLS ONLY COME FROM
OTHER CELLS".
His statement debunked
"Theory of Spontaneous Generation"

7. Cell Theory

The COMBINED
work of Schleiden,
Schwann, and
Virchow make up
the modern
CELL
THEORY.

8. The Cell Theory states that:
1. All living things are composed of a cell
or cells.
2. Cells are the basic unit of life.
3. All cells come from preexisting cells.

9. Explore



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
Plant vs. Animal Lab
You will observe different types of plant and animal cells
under the microscope and record your observations.
Gel Cells for Diffusion
You will build a model of a cell to understand why cells
when they reach a certain size stop growing.
Edible Model Cells
Using your textbook and other resources, you will make a
model of a prokaryotic and eukaryotic cell using gelatin and
other edible materials. The gelatin will represent the cell
membrane/cytoplasm and other edible components will be
representative of the cellular organelles.

10. Explain: Cell Diversity

Cells within the same organism show
Enormous Diversity in:



Size
Shape
Internal Organization

11. 1. Cell Size

Female Egg - largest cell in the human
body; seen without the aid of a microscope

Most cells are visible only with a
microscope.

12. Cells are small for 2 Reasons
Reason 1:

Limited in size by the RATIO between their Outer
Surface Area and Their Volume.
A small cell has more SURFACE AREA than a
large cell for a GIVEN VOLUME OF CYTOPLASM.

13. Cells are Small
Reason 2:

THE CELL'S NUCLEUS (THE BRAIN)
CAN ONLY CONTROL A CERTAIN
AMOUNT OF LIVING, ACTIVE
CYTOPLASM.

14. 2. Cell Shape


Diversity of form reflects a
diversity of function.
THE SHAPE OF A CELL
DEPENDS ON ITS
FUNCTION.

15. 3. Internal Organization
Cell membrane
Cytoplasm
Prokaryotic Cell
Cell membrane
Cytoplasm
Eukaryotic Cell
Nucleus
Organelles

16. Compare and Contrast
Prokaryotes
Eukaryotes
Cell membrane
Contain DNA
Ribosomes
Cytoplasm
Nucleus
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Vacuoles
Mitochondria
Cytoskeleton

17. Prokaryotic Examples
ONLY Bacteria

18. EUKARYOTIC CELLS
Two Kinds:
Plant and Animal

19. Eukaryotic Example

20. Section 7-2
Smooth endoplasmic
reticulum
Vacuole
Ribosome
(free)
Chloroplast
Ribosome
(attached)
Cell
Membrane
Nuclear
envelope
Cell wall
Nucleolus
Golgi
apparatus
Nucleus
Mitochondrion
Rough endoplasmic reticulum
Plant Cell

21. Venn Diagrams
Compare and Contrast
Animal Cells
Centrioles
Plant Cells
Cell membrane
Ribosomes
Nucleus
Endoplasmic reticulum
Golgi apparatus
Lysosomes
Vacuoles
Mitochondria
Cytoskeleton
Cell Wall
Chloroplasts

22. Internal Organization


Cells contain
ORGANELLES.
Cell Components
that PERFORMS
SPECIFIC
FUNCTIONS FOR
THE CELL.

23. Cellular Organelles

The Plasma
membrane



The boundary of the
cell.
Composed of three
distinct layers.
Two layers of fat and
one layer of protein.

24. The Nucleus

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Brain of Cell
Bordered by a porous
membrane - nuclear
envelope.
Contains thin fibers of DNA
and protein called
Chromatin.
Rod Shaped Chromosomes
Contains a small round
nucleolus

produces ribosomal RNA
which makes ribosomes.

25. Ribosomes



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Small non-membrane
bound organelles.
Contain two sub units
Site of protein synthesis.
Protein factory of the cell
Either free floating or
attached to the
Endoplasmic Reticulum.

26. Endoplasmic Reticulum


1.
2.
Complex network of
transport channels.
Two types:
Smooth- ribosome
free and functions in
poison detoxification.
Rough - contains
ribosomes and
releases newly made
protein from the cell.

27. Golgi Apparatus


A series of flattened
sacs that modifies,
packages, stores,
and transports
materials out of the
cell.
Works with the
ribosomes and
Endoplasmic
Reticulum.

28. Lysosomes

Recycling Center



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Recycle cellular debris
Membrane bound
organelle containing a
variety of enzymes.
Internal pH is 5.
Help digest food
particles inside or out
side the cell.

29. Centrioles

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Found only in animal
cells
Paired organelles
found together near the
nucleus, at right angles
to each other.
Role in building cilia
and flagella
Play a role in cellular
reproduction

30. Cytoskeleton
Cell membrane
Endoplasmic
reticulum
Microtubule
Microfilament
Ribosomes
Mitochondrion

31. Cytoskeleton



Framework of the cell
Contains small microfilaments and larger
microtubules.
They support the cell, giving it its shape
and help with the movement of its
organelles.

32. Mitochondrion




Double Membranous
It’s the size of a bacterium
Contains its own DNA;
mDNA
Produces high energy
compound ATP

33. The Chloroplast



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Double membrane
Center section contains
grana
Thylakoid (coins) make
up the grana.
Stroma - gel-like
material surrounding
grana
Found in plants and
algae.

34. The Vacuole


Sacs that help in
food digestion or
helping the cell
maintain its water
balance.
Found mostly in
plants and protists.

35. Cell Wall




Extra structure surrounding its plasma
membrane in plants, algae, fungi, and
bacteria.
Cellulose – Plants
Chitin – Fungi
Peptidoglycan - Bacteria

36. Section 7-1
Review
A. The Discovery of the Cell
1.Robert Hooke
2.The Cell Theory
B. Exploring Cell Diversity
1. Size
2. Shape
3. Internal Organization
C. Two types of cells
1. Prokaryote
2. Eukaryote

37. Cell Types (Review)
Eukaryotic
1. Contains a nucleus and
other membrane bound
organelles.
2. Rod shaped
chromosomes
3. Found in all kingdoms
except the Eubacteria
and Archaebacteria
Prokaryotic
1.
Does not contain a
nucleus or other
membrane bound
organelles.
2.
Circular chromosome
3.
Found only in the
Eubacteria and
Archaebacteria
Kingdoms

38. Elaborate


Modeling the Animal Cell
You will create a cellular game. By
following the procedure, you will create
a closed circuit using a battery, wires,
paper spreaders, and an LED light that
will turn on when they match up the
organelle with its correct function

39. Evaluate


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The students will create an edible cell
model and correctly identify the location and
function of at least 8 organelles.
The students will correctly match at least 10
organelles with their function, using the
animal and plant cell model.
The students will draw and label both a
prokaryotic and a eukaryotic cell. Pass/Fail
The students will complete a Venn diagram
comparing both prokaryotic and eukaryotic
cells showing at least two differences.