1. Cell Organelles
Honors Biology I

2. Cell Organelles
Organelle= “little organ”

3. Cell Walls Not found in Animal cells Support structure
Made of cellulose
Plasmodesmata allow materials to pass from one cell to the next

4. Centrioles Found only in animals Formed from protein tubulin
Found near nucleus in the centrosome
Help organize cell division

5. Cytoskeleton “support and transport structure”
Network of protein filaments
1. Microfilaments
Thread-like
Made of protein actin
2. Microtubules
Hollow structures
Made of protein tubulin
Important during cell division when moving chromosomes

6. We have already covered this!
Plasma Membrane
We have already covered this!

7. Cilia Numerous hair-like extensions of the cell membrane
Type of microtubule
used for locomotion and aid in feeding
Ex: respiratory cells

8. Flagella Long whip-like extensions of the cell membrane
Type of microtubule
Used for locomotion
Ex: sperm cells

9. Nucleus: Main Office “control center” Contains DNA Nuclear envelope
Composed of 2 membranes
Contains nuclear pores that allow material to move in and out of nucleus

10. Cells normally contain a single nucleus
Chromatin
DNA bound to protein
Condenses into chromosomes during cell division
Nucleolus
Produces ribosomes
Cells normally contain a single nucleus
Cells such as liver and muscle cells have more than one due to amount of organelles that need controlling

11. Cytoplasm vs cytosol
All the stuff in between the organelles is 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.”

12. Ribosomes “machines” Makes proteins
Consists of ribosomal RNA and protein
Free Ribosomes
Found in the cytosol
Make proteins for use in that cell
Attached Ribosomes
Attached to rough ER
Make proteins to be transported elsewhere or to be inserted in the membrane

13. Endoplasmic Reticulum
“conveyor belt”
Consists of a series of membraneous tubules that connect to the nuclear envelope
Rough ER has ribosomes and carries proteins throughout the cell
Smooth ER does NOT have ribosomes and makes membrane lipids and detoxifies drugs
Liver cells have large amounts of smooth ER

14. Vesicles Transport organelles Endocytosis and exocytosis
Protein transport

15. Golgi Apparatus “mail room” Stack of membraneous sacks
Receives proteins from the Rough ER and then modifies, sorts and packages them in vesicles for storage or transport

16. Vacuoles “storage” Sac-like membrane bound structures
Store water, salts, proteins, carbohydrates etc.
Plant cells have a large central Vacuole
Pressure inside offers support to plant structures
Animal cells have smaller vacuoles

17. Chloroplasts “solar power” Only found in Plant cells Double membrane
Site where photosynthesis takes place
Contains chlorophyll pigment that absorbs light
Have their own DNA

18. Mitochondria “Powerhouse” Double membrane organelle
outer membrane
Inner membrane: contains folds called Cristae which increases surface area for cellular respiration to take place
Convert chemical energy stored in food into compounds that the cell can use

19. Inherited from your mom
Contain their own DNA
Numerous in muscle cells

20. Lysosomes “clean up crew” Small organelles filled with enzymes
Digests lipids, carbohydrates and proteins so that they can be used by the cell
Get rid of “worn-out” organelles

21. Endosymbiotic Theory
Lynn Margulis suggested that mitochodria and chloroplasts are descendants of prokaryotes
Large prokaryotes consumed smaller prokaryote which developed a symbiotic relationship
Evolution of first eukaryote