1. CHAPTER 3 Cell Structure and Function. 3. 1 Cell Theory. 3
CHAPTER Cell Structure and Function 3.1 Cell Theory 3.2 Cell Organelles 3.3 Cell Membrane 3.4 Diffusion and Osmosis 3.5 Active Transport B

2. I. Cell Theory A. Early studies led to the development of the
It was the result of the collective work of many scientists.
1665 Robert Hooke used the word “cell” to describe the spaces in cork
1674 Anton Von Leeuwenhoek observed living cells and called them “animalcules”

3. I. Cell Theory (continued)
1838 Matthias Schleiden was the first to note that plants were made of cells
1839 Theodor Schwann concluded that animals are made of cells
1855 Rudolf Virchow reported that all cells come from other cells
Cell Theory video

4. Cell Theory All organisms are made of cells.
The cell is the most basic unit of life.
Structure and function
All cells are produced by other cells

5. Levels of Organization in Living Things

6. CELLS
TISSUES
ORGANS
ORGAN SYSTEMS
ORGANISM

7. 2 Categories of Cells
1. Prokaryotic Cells lack a nucleus and most internal
structures of eukaryotic cells
Pro = Before
Karyotic = nucleus
All prokaryotic cells are microscopic single-celled organisms whose DNA is suspended in the cytoplasm
Bacteria are the ONLY examples of prokaryotes.

8. 2 Categories of Cells 2. Eukaryotic cells have a nucleus with DNA
Eu = True Karyotic = nucleus
- Have other membrane bound organelles Organelles = specialized structures that perform specific jobs “tiny organs”
- There are 2 types: Animal and Plant Cells
- Eukaryotic cells are found in:
animals, plants, fungi and protists.
Prokaryote vs eukaryote video

9. II. Cell Organelles - Animal Cell
6. Ribosomes on ER
4. Nucleolus
6. Ribosomes in cytoplasm
2. Nucleus
1. Cell Membrane
3. Nuclear Membrane
8. Mitochondria
5. Rough ER
5. Smooth ER
10. Vacuole
3. Nuclear pore
11. Centrioles
7. Golgi
12. Cytoplasm
9. Lysosome

10. Cells are highly organized structures 1. Cytoskeleton - Cyto = cell
II. Cell Organelles (continued)
A. Cells have an internal structure
Cells are highly organized structures
1. Cytoskeleton
- Cyto = cell
Network of proteins and fibers that is constantly changing to meet the needs of the cell
Like the support beams or infrastructure of the school
2. Cytoplasm
Cyto = cell Plasm = fluid
The fluid portion of the cell that fills the space between the nucleus and the cell membrane
in eukaryotic cells
Like the inside of the school “air”

11. II. Cell Organelles (continued)
B. Several organelles are involved in making and processing
protein
1. Nucleus – the brain of the cell
Located at the center of the cell
Contains our genetic information,
Controls all of the cell’s activities
Determines what proteins are made
“Like the principal’s office”
2. Nuclear Envelope/Membrane:
Double Membrane that surrounds the nucleus
Contains nuclear pores that allow certain materials to move in and out of the nucleus
“Like the walls and doors surrounding the principal’s office”
3. Nucleolus:
Located inside of the nucleus
Made of DNA
Makes ribosomes
“Like the principal”

12. 4. Endoplasmic Reticulum –
interconnected network of thin folded membranes
helps move materials within cell
Passageways
“Like hallways and staircases”
Two types
It’s called rough ER when it
has ribosomes on it.
- Site of protein making
- “Like the staircases and hallways”
It’s called smooth ER when there
are no ribosomes on it.
- Site of lipid making and other functions
- “Like the elevators”

13. Made from the nucleolus Job is to make protein
5. Ribosome:
Made from the nucleolus
Job is to make protein
Ribosomes are found in three places:
1. Nucleolus
2. Attached to the Rough Endoplasmic Reticulum.
3. Freely floating throughout the cytoplasm
“The information of the school”
6. Golgi Apparatus
packs, stores and ships out proteins to the
cell membrane so they can be released from the cell and
distributed to the body.
“Like the mailroom or guidance office”
7. Vesicles
Tiny sacs that isolate and transport specific
molecules out of the cell.
“Like envelopes”

14. Glucose + Oxygen ATP+ Carbon dioxide + water
C. Other organelles have various functions
1. Mitochondria:
The “Powerhouses” of the cell because they produce energy from food that was digested.
This is where the process of cellular respiration is carried out.
Cellular respiration is a
process that breaks down
food (glucose) into energy
(ATP) that can
be used by the cell.
“Like the generators of the
school”
Glucose + Oxygen ATP+ Carbon dioxide + water

15. membrane bound organelles that contain enzymes
2. Lysosomes:
membrane bound organelles that contain enzymes
Digestive sacs – destroy damaged or worn out cell parts and get rid of
bacteria.
“Like the clean-up crew”
3. Vacuole:
Fluid filled sac that stores water, food, ions, minerals, protein and carbohydrates.
“Like kitchens”
These are much larger in plant cells – central vacuole

16. Why is the vacuole larger in a plant cell?
Because plants rely on rain in order to receive water. Therefore the vacuole needs to be much larger because the plant has to be able to store its water for long periods of time when there is no rain.
Without water a plant can not perform photosynthesis!

17. Help with cell division in a process known as mitosis -
4. Centrosome
it contains the centrioles
5. Centrioles:
Help with cell division in a
process known as mitosis -
form of reproduction.
Found in pairs
Small cylinder shaped organelle
Only found in animal cells
“like the students”

18. Virtual Cell Tour
Take a Virtual Cell Tour

19. Movement of Animal Cells
Animal cells can move by either cilia or flagella.
Both composed of microtubules.
Cilia - short, hair-like projections that produce movement.
Flagella – a whip-like tail used for locomotion.

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

21. Plant Cell
A plant cell contains every organelle of an animal cell EXCEPT the centrioles!
Plant cells also have 2 additional organelles that are not found in an animal cell.
What are the 2 organelles of a plant cell that are not found in an animal cell?

22. Carbon dioxide + Water  Glucose + Oxygen
1. Chloroplasts:
Found only in plant cells
Are needed for photosynthesis
Contain the green pigment chlorophyll
Chlorophyll can trap energy from the sun and use it for photosynthesis, so plants can make their own food( glucose) through photosynthesis.
Carbon dioxide + Water  Glucose + Oxygen

23. 2. Cell wall: Found in cells of plants, algae, fungi, and bacteria
It is a thick outer covering surrounding the cell membrane
Provides support and protection
Allows the stem of the plant to stand upright in order to carry out photosynthesis.

24. Virtual Cell Tour Take a Virtual Cell Tour
Travel through the cell video

25. 3.3 Cell Membrane 3.4 Diffusion and Osmosis 3.5 Active Transport

26. 3.3. Cell Membrane
Cell membranes are composed of two phospholipid layers.
The cell membrane has two major functions.
forms a boundary between inside and outside of the cell
Allows materials to pass in and out of the cell (selectively permeable)
Lipid bilayer
cholesterol
protein
channel

27. Phospholipid from the cell membrane
Fluid Mosaic Model - describes the arrangement of molecules that make up a cell membrane.
Flexible membrane
Moves from side to side like a fluid
Has a variety of molecules in it like a mosaic (different textures/patterns)

28. 3.3. Cell Membrane (continued)
Cell Membrane is selectively permeable
Some molecules can pass while others can not

29. Movement across a cell membrane
Passive Transport
Requires no energy for molecules to move across a cell membrane.
Two types of Passive Transport
1. Diffusion
2. Osmosis
3. Facilitated Diffusion
Active Transport
Requires energy in order for molecules to move across a cell membrane.
Two types of Active Transport
1. Protein Pumps
2. Endocytosis
3. Exocytosis

30. IV. Diffusion and Osmosis Movement across a cell membrane
Diffusion: Movement of substances from an area where there are more to where there is less along a concentration gradient.
- This occurs until there is a balance of substances called
equilibrium
- The moving substance has to be smaller than the cellular pore

32. *Water moves to dilute the substance that is too large!
Osmosis – Diffusion of water across a membrane from an area where there is more water to an area where there is less water in order to reach equilibrium.
*This occurs when a solute or substance is too large to pass through the cell membrane.
*Water moves to dilute the substance that is too large!
video

33. 3 types of osmotic solutions
Hypertonic solution – when there is more water inside the cell, water will move out of the cell in order to dilute the higher substance.
- Causes a cell to shrink
Hypotonic solution – when there is more water outside the cell, water will move into the cell in order to dilute the higher substance.
- Causes a cell to swell or expand
Isotonic solution – when both sides of the cell membrane are at equilibrium

34. Osmosis
Hypertonic - Because the solution outside the cell is greater than inside the cell – Water will leave; causing the cell to shrink
Hypotonic - Because the solution outside the cell is less than inside the cell – Water will enter; causing the cell to swell
Isotonic - Because the solution outside the cell is equal or the same as inside the cell – Water will move back and forth at an equal rate

35. Facilitated Diffusion
Some particles can not diffuse through the membrane because of their size, or their charge
They need to pass through a carrier protein
Diffusion with help (High to low)
Osmosis rap

36. Active transport – molecular pumps
Move things AGAINST the concentration gradient: low to high
Requires energy! ATP!!
A transport protein PUMPS the molecule to the other side of the membrane

37. Active Transport
Endocytosis – process of taking molecules into a cell by engulfing them in a membrane
Exocytosis – process of releasing a substance out a cell by the fusion of a vesicle with the cell membrane.
Video

38. Pin the Organelle on the Animal Cell

39. Pin the Organelle on the Plant Cell
Smooth endoplasmic
reticulum
Ribosome
(free)
Ribosome
(attached)
Cell
Membrane
Nuclear
envelope
Nucleolus
Golgi apparatus
Nucleus
Mitochondrion
Rough endoplasmic reticulum