1. Cell Organelles
Use this presentation in conjunction with the Cell Organelle note-taking worksheet. Run through the entire presentation before using it in class so that you know what’s coming next! It helps to print the outline and notes to have with you while presenting so that there are no surprises. –JessB.org

2. SO, WE ARE GOING TO STUDY CELLS!
A little review…
All organisms are made up of one or more cells.
The life functions of an organisms are carried out by its cell or cells.
All cells come from other, already existing cells.
SO, WE ARE GOING TO STUDY CELLS!

3. Cell Size
Most cells are less than a tenth of a millimeter in diameter.
Unusually large cells:
Sciatic Nerve (1.5m)
Ostrich Egg (1.4km)
Giraffe Vagus Nerve (5m)

4. TWO TYPES OF CELLS PROKARYOTIC: EUKARYOTIC:
Do NOT membrane-bound organelles.
DNA is one big loop, and is just suspended in the cytosol.
Kingdoms Archaea and Bacteria.
EUKARYOTIC:
Contain membrane-bound organelles.
DNA is in chromosomes and bound within a nuclear membrane.

5. Cell Organelles Organelle= “little organ”
Found only inside eukaryotic cells
All the stuff in between the organelles is a fluid substance called cytosol
Everything in a cell except the nucleus is cytoplasm
You may or may not wish to distinguish between cytosol and cytoplasm. The correct use of each term is shown here. Most high school textbooks, however, use the word “cytoplasm” to mean “cytosol.”

6. Cell Membrane Boundary of the cell
Main component is the phospholipid bilayer
Contains proteins that act as “channels” for molecules to transport in and out of the cell.
Emphasize word parts here:
phospho= phosphate head; lipid= fatty acid tail
bi= 2

7. Nucleus Control center of the cell Contains DNA
Surrounded by a double membrane
Contains the Nucleolus, which produces ribosomes.
Usually the easiest organelle to see under a microscope
Usually one per cell
Cells with more than one nucleus include muscle cells and liver cells, largely because of the massive volume of cytoplasm and number of organelles that need controlling.

8. That looks familiar…what is a polypeptide?
Ribosome
Site of protein synthesis
Found attached to rough ER or floating free in cytosol
Produced in a part of the nucleus called the nucleolus
A polypeptide is a chain of amino acids. In this diagram, you can see the ribosome is making a polypeptide, also known as a protein.
That looks familiar…what is a polypeptide?

9. Endoplasmic Reticulum
A.k.a. “ER”
Connected to nuclear membrane
Highway of the cell
Rough ER: studded with ribosomes; it makes proteins
Smooth ER: no ribosomes
makes lipids and steroids
Breaks down toxins in liver cells
It’s not necessary that the students can read the labels here; just point out the black dots are ribosomes.

10. Cytoskeleton Acts as skeleton and muscle Provides shape and structure
Helps move organelles around the cell
Made of three types of filaments
Actin, also found in muscle cells, mainly help maintain cell shape in their cytoskeletal role. Microtubules mostly move organelles around the cell. Intermediate filaments also provide structural support.

11. Golgi Apparatus Looks like a stack of plates
Each sac contains a different sets of enzymes
stores, modifies and packages proteins
Proteins are sent to the cytosol or out of the cell.
Molecules transported to and from the Golgi by means of vesicles
AKA Golgi Complex. It is not necessary that the students read the labels, this diagram gives them a general idea of the Golgi’s shape.

12. Vacuoles Large central vacuole usually in plant cells
Many smaller vacuoles in animal cells
Storage container for water, food, enzymes, wastes, pigments, etc.
The image is 2D, so it must have been a light microscope or TEM. If the cell is very tiny, then a TEM was used. Otherwise, a strong light microscope could have captured this image.

13. Lysosomes (I) Garbage disposal of the cell
Contain digestive enzymes that break down wastes (proteins, polysaccharides, fats, nucleic acids)
Rough ER makes the membranes and enzymes.
Students should recognize the shapes of the Golgi and ER even if they cannot read the captions.

14. Lysosomes (II) Fight Disease: Digestion Recycling Cell Components
In humans, cells called Macrophages absorb harmful bacteria.
Bacterium is delivered to lysosome
Enzymes in lysosome break down bacterium, killing it.
Digestion
Recycling Cell Components
Lysosomes surround damaged or non-functioning organelles
Organells broken down into building blocks so they can be reused
Killing the cell
if lysosomes all burst at the same time, the enzymes digest and kill the cell.
Syndactyly – webbed fingers.
The hands of a human embryo are webbed until lysosomes digest the excess tissue. Sometimes this does not happen.
Students should recognize the shapes of the Golgi and ER even if they cannot read the captions.

15. Mitochondria “Powerhouse of the cell”
Cellular respiration occurs here to release energy from food for the cell to use
Bound by a double membrane
Outer membrane
Inner membrane
Contains many folds called cristae.
Increased surface are for chemical reactions to occur.
Fluid inside inner membrane called matrix.
Some cells only contain one mitochondrion. Cells requiring a lot of energy (muscle cells, brain cells) may have thousands of mitochondria.
Explain that this diagram shows the mitochondria cut open to reveal the internal membranes.

16. Chloroplast Found in plant cells
Contains the green pigment chlorophyll
Site of food (glucose) production via PHOTOSYNTHESIS: use energy from the sun to make their own food.
Bound by a double membrane
Chloroplasts absorb light, which is the catalyst for photosynthesis.

17. Cell Wall Found in plant and bacterial cells Rigid, protective barrier
Located outside of the cell membrane
Made of cellulose (fiber)
This is an actual microscopic image. Explain that the colors are added digitally to enhance the different parts.

18. Centriole Aids in cell division Usually found only in animal cells
Made of microtubules
Microtubules are also part of the cytoskeleton.

19. Organelles working together – production of insulin
Insulin protein information is in the DNA within the nucleus.
A copy of the DNA is sent out of the nucleus to the rough ER.
The ribosomes in the rough ER use the copy of DNA to make the protein that will eventually become insulin.
Vesicles from the smooth ER package the protein for transport to the Golgi Body.
In the Golgi Body, the proteins are processed to form insulin protein and packaged.
Insulin is released from the cell.
Microtubules are also part of the cytoskeleton.

20. Quick Review Which organelle is the control center of the cell?
Nucleus
Which structure holds the cell together?
Cell membrane
Which organelles are not found in animal cells?
Cell wall, central vacuole, chloroplasts
Which organelle helps plant cells make food?
Chloroplasts
What does E.R. stand for? What does it do?
Endoplasmic reticulum. It’s a ‘highway’ for the cell.
You may choose to delete the answers from the PowerPoint or change the animation so that they come in after all 5 questions are asked in case you want to quiz students individually at the end.