1. “Every Part has its Own Job to do….”
Organelle Functions
“Every Part has its Own Job to do….”

2. Organelles Organelles are the small parts of a cell.
Each organelle has a specific function or job. The shape (structure) of the organelle allows it to have this function.
You should learn to:
1. Recognize and label organelles in a diagram.
2. Describe the functions of each organelle.

3. The Way it’s Put Together
Structure vs. Function
Structure
How it’s Built
What it’s Made Of
Parts
Shapes
The Way it’s Put Together
Sizes
Function
What it Does
How it Works
It’s Jobs
The Way it works
Steps in the Process
“The Structure Determines the Function”
This is almost a “Law” of Biology – it is true at all Levels of Organization
Errors in structure cause errors in function, which will cause diseases, disorders, etc.

4. Your Assignment
Finish these notes and turn them in by the end of the period.
You should draw an arrow on each diagram showing the organelle of interest.
The “main function” of each organelle is underlined to help you know what is most important about it.

5. Cytoplasm Found between the nucleus and the cell membrane
It is More than just the “fluid filling the cell”
It allows chemical reactions to occur, since the dissolved molecules can interact with each other easily.
Most organelles are floating in the cytoplasm

6. Cell Wall You do NOT have any cell walls! WARNING:
Neither do ANY other animals!
But you eat them whenever you eat fruits or vegetables!!
And you use them every time you work with something wooden! And you are writing on them right now! And you might be wearing them if your clothes are cotton!
Found only in plants, fungi, and bacteria
Thick outer layer that provides support and protection for cell

7. Cell Membrane
Found in all cells (plants and animals, prokaryotes and eukaryotes)
Many important functions:
Controls entry and exit of molecules in and out of cell (it is a “semipermeable membrane”)
Recognizes surrounding cells and other parts of the environment
Joins cells together into tissues
Sends & receives messages from other cells

8. Nucleus Found in all eukaryotic cells
Controls all cell activities using instructions from DNA
Contains nucleolus and chromatin (DNA)
Pores in nuclear membrane allow RNA to exit nucleus
chromatin

9. Nucleolus Builds ribosomes
Ribosomes exit nucleus to function in cytoplasm

10. Chromatin Loose, unwound strands of DNA
Unwound DNA allows access to genes
DNA winds up tightly into chromosomes during mitosis
Chromosomes carry the genetic code with instructions for all of a cell’s traits & actions
DNA Molecules
Genes
Chromosomes

11. Mitochondrion “The powerhouse of the cell”
Provides energy by “burning” sugar with oxygen
Conducts aerobic cellular respiration
Equation for Cellular Respiration
Glucose
Sugar
Carbon
Dioxide
Oxygen +
Water +
Energy!! +

12. Ribosomes Build Proteins following instructions from DNA
“Free Ribosomes” floating in cytoplasm
“Attached Ribosomes” on Rough E.R.
Magnified View of
Ribosome
(Dots)
Large Subunit
Small Subunit

13. Cilia Rows of many tiny “hairs” that act like oars
Move the cell or move materials past the cell
Singular: cilium plural: cilia
A cell with cilia is “ciliated”
A protist that moves with cilia is a “ciliate”

14. Centrioles Found only in animal cells Builds the cytoskeleton
Also has an important role in cell division: it pulls the pairs of chromosomes apart

15. Vacuoles Storage compartments
May hold food molecules, water, or waste molecules
Water-filled vacuole is very large in plant cells – it influences the shape of the plant, since the plant wilts when it is empty

16. Golgi Apparatus
Secretes important molecules which act outside of the cell
Not involved in excretion (release of waste molecules)
Golgi packs helpful molecules into vesicles, and the vesicles join with the cell membrane to release the molecules
Vesicle ready to release
important molecules like
hormones, enzymes, or
neurotransmitters.

17. Flagellum Long whip-like tail Some cells have more than one
Move the cell or move materials past the cell
Singular: flagellum plural: flagella
A cell with a flagellum is “flagellated”
A protist that moves with a flagellum is a “flagellate”

18. Endoplasmic Reticulum
Transports molecules throughout the interior of the cell
Rough E.R. has ribosomes attached to it; its main job is to manufacture and transport proteins
Smooth E.R. does not have ribosomes; it mostly transports fats and carbohydrates

19. Chloroplast Found only in plant cells (and some protists)
Traps the sun’s energy and builds food molecules
Conducts photosynthesis
Chlorophyll is a green molecule inside the chloroplast
(membrane)
(sacs)
Equation for Photosynthesis
(space)
Carbon
Dioxide
Glucose
Sugar +
Water +
Light +
Oxygen

20. Cytoskeleton Made of microfilaments and microtubules
Supports the cell and helps keep its shape
Electron Micrograph of Cytoskeleton
Green Fibers =
Cytoskeleton
Purple Circle =
Nucleus

21. Lysosomes Contain powerful digestive enzymes
Break down foreign substances and worn-out cell parts
May cause misfunctioning cells to self-destruct
Only in animal cells