1. Organelles: The Structure of the Cell.
Indicator B-2.2:
Summarize the structures and functions of organelles found in a eukaryotic cell.

2. Key Concepts
Organelles

3. It is essential for you to know:
That an organelle is a cell structure that performs a specialized function within a eukaryotic cell.
The structure and function of various organelles within a eukaryotic cell.
How to locate and identify each organelle when presented with a scientific drawing, diagram, or model of a eukaryotic cell.

4. OBJECTIVES Describe the functions of the major cell organelles.
Identify the structures of various cell organelles.

5. Basic Cell Structure All cells have 3 things:
Cell membrane or plasma membrane
Controls what comes in and out of cell
DNA (the control center)
The genetic information of the cell
Cytoplasm or Cytosol
The jelly-like substance which fills the inside

6. A Day in a Cell
If we could take a trip inside a cell and spend one day there, we would see all kinds of things. It would remind us of what a factory looks like. Let’s take a look:

10. Cells have an internal structure.
Cytoskeleton
Microtubules
Microfilaments

11. Cytoskeleton
Microtubule: hollow tube of protein that maintains cell shape & can serve as “tracks” along which organelles move.
Helps separate chromatin in division: forms centrioles.
Helps form cilia & flagella in some.
Microfilaments: long, thin fibers that function in movement & support of cell
Narrower than microtubules
Produce a tough, flexible framework that supports the cell.

12. Organelles in the Cytoplasm
The cytoplasm contains specialized structures called organelles
Ribosomes
Endoplasmic reticulum (rough & smooth)
Golgi Apparatus
Lysosomes
Vacuoles
Chloroplasts
Mitochondria
Cilia
Flagella

13. Making a Protein Several organelles are involved in making a protein.
This is the main function of a cell.

14. Nucleus Contains the chromosomes, which are comprised of DNA
Deoxyribonucleic Acid
Controls the cell’s genetic information.

15. Nucleus
The nuclear envelope is a double-membrane layer that surrounds the nucleus
Has thousands of nuclear pores
RNA and other material through here
The nucleolus is in the nucleus, a small dense region
The assembly of ribosomes begins here. Ribosomes aid in the production of proteins.

16. Organelles in the Cytoplasm
Ribosome: small particle in the cell on which proteins are assembled, made of protein and RNA
can be “free” or attached to endoplasmic reticulum

17. Organelles in the Cytoplasm
Endoplasmic reticulum: (ER), in eukaryotic cells; the organelle in which components of the cell membrane are assembled and some proteins are modified.
Rough ER: ribosomes attached, the part that is involved in making proteins
Smooth ER: no ribosomes attached, contains enzymes that perform specialized tasks like the synthesis of lipids.

18. Organelles in the Cytoplasm
Golgi Apparatus: stack of membranes in the cell in which enzymes attach carbs and lipids to proteins
When proteins are produced by ER they are moved to the Golgi Apparatus

19. Organelles in the Cytoplasm
Vacuoles: saclike structure that stores materials like water, salt, proteins, and carbohydrates.
Plants have a central vacuole filled with liquid to create pressure to make it possible to support heavy structures.
Smaller vacuoles are called vesicles, which are found in animal cells.

20. Organelles in the Cytoplasm
Lysosomes: small organelles filled with enzymes
Breaks down lipids, carbs, and proteins from food into useful particles.
Can remove debris from cells.

21. Organelles in the Cytoplasm
Mitochondria: release energy from stored food molecules
Use energy from food to make high-energy compounds that the cell can use to power growth, development, and movement.
Contains its own DNA and can reproduce on its own.

22. Organelles in the Cytoplasm
Centrioles are cylinder-shaped organelles made of short microtubules arranged in a circle.
Aid the cell in mitosis or meiosis.
Not found in plant cells.

23. Plant Cells Have Specialized Structures
Chloroplasts: found in plants
use the energy from sunlight to make energy-rich food molecules via photosynthesis
Contain chlorophyll
Contains its DNA and can reproduce on its own.

24. Plant Cells Have Specialized Structures
The cell wall lies outside the cell membrane and gives the cell support, protection, and strength.
Unlike the cell membrane, the cell wall is very rigid.

25. Cells Move Too!
Cilia are short hair-like projections responsible for the movement of animal cells or protists.
Flagella are long whip-like projections responsible for the movement of some animal cells, bacteria, or protists.