1.
Section 2: Inside the Eukaryotic Cell <ul><li>Preview </li></ul><ul><li>Bellringer </li></ul><ul><li>Key Ideas </li></ul><ul><li>The Framework of the Cell </li></ul><ul><li>Directing Cellular Activity </li></ul><ul><li>Protein Processing </li></ul><ul><li>Storage and Maintenance </li></ul><ul><li>Energy Production </li></ul><ul><li>Summary </li></ul>

2.
Bellringer <ul><li>Use a light microscope to view a slide of a eukaryotic cell. Try to find the nucleus of the cell and give your reason why you identified the structure as the nucleus. </li></ul>

3.
Key Ideas <ul><li>What does the cytoskeleton do? </li></ul><ul><li>How does DNA direct activity in the cytoplasm? </li></ul><ul><li>What organelles are involved in protein production? </li></ul><ul><li>What are vesicles and vacuoles? </li></ul><ul><li>How does the cell get energy? </li></ul>

4.
The Framework of the Cell <ul><li>The cytoskeleton helps the cell move, keep its shape, and organize its parts. </li></ul><ul><ul><li>Like a human’s skeleton </li></ul></ul><ul><li>There are three different kinds of cytoskeleton fibers: microfilaments, microtubules, and intermediate fibers. </li></ul>

5.
Directing Cellular Activity <ul><li>DNA contains instructions for making proteins which control most of the activity of the cell. </li></ul><ul><li>The DNA of eukaryotic cells is stored in the nucleus. </li></ul>

6.
Directing Cellular Activity, continued <ul><li>Nucleus </li></ul><ul><li>The nuclear envelope surrounds the nucleus. </li></ul><ul><li>Nuclear pores located on the nuclear envelope act as channels to allow certain molecules to move in and out of the nucleus. </li></ul><ul><li>The nucleolus is a structure within the nucleus where ribosomes are made. </li></ul>

7.
The Nucleus A B C D Click to animate the image.

8.
Directing Cellular Activity, continued <ul><li>Ribosomes </li></ul><ul><li>Each ribosome in a cell is made of RNA and many different proteins. </li></ul><ul><li>Free ribosomes make proteins that remain inside the cell. </li></ul>

9.
Protein Processing <ul><li>Proteins that are sent outside the cell are packaged in vesicles. Vesicles are small, membrane-bound sacs that enclose the proteins. </li></ul><ul><ul><li>Like sending mail (need to put mail in an envelope) </li></ul></ul><ul><li>The endoplasmic reticulum and Golgi apparatus are organelles involved in preparing proteins for extracellular export. </li></ul>

10.
Protein Processing, continued <ul><li>Endoplasmic Reticulum </li></ul><ul><li>The endoplasmic reticulum, or ER, is a system of internal membranes that moves proteins and other substances through the cell. </li></ul><ul><li>The endoplasmic reticulum is divided into two portions: rough ER and smooth ER. </li></ul>

11.
Endoplasmic Reticulum (ER)

12.
Protein Processing, continued <ul><li>Endoplasmic Reticulum </li></ul><ul><li>The portion of the ER with attached ribosomes is called rough ER because it has a rough appearance </li></ul><ul><li>The portion of the ER with no attached ribosomes is called smooth ER because it has a smooth appearance </li></ul>

13.
Visual Concept: Endoplasmic Reticulum (ER) and Ribosomes

14.
Protein Processing, continued <ul><li>Golgi Apparatus </li></ul><ul><li>The Golgi apparatus is a set of flattened, membrane-bound sacs. </li></ul><ul><li>The Golgi apparatus helps modify, sort, and package cell products for distribution. </li></ul>

15.
Golgi apparatus

17.
Storage and Maintenance <ul><li>Lysosomes </li></ul><ul><li>A lysosome is a vesicle produced by the Golgi apparatus that contains enzymes that break down large molecules. </li></ul><ul><li>Lysosomes recycle old or damaged organelles and digest food particles to provide nutrients for the cell. </li></ul><ul><li>(the “stomach” of a cell) </li></ul>

18.
Visual Concept: Lysosomes

19.
Storage and Maintenance, continued <ul><li>Vacuoles </li></ul><ul><li>A vacuole is a fluid-filled vesicle found in the cytoplasm of many plant cells. </li></ul><ul><li>Plant cells contain a large compartment called the central vacuole, which stores water, ions, nutrients, and wastes. </li></ul><ul><li>When water fills the central vacuole, the cell becomes rigid, allowing the plant to stand up. When the vacuole loses water, the cell shrinks, and the plant wilts. </li></ul>

20.
Visual Concept: Vacuoles

21.
Energy Production, continued <ul><li>Chloroplasts </li></ul><ul><li>A chloroplast is an organelle found in plant and algae cells that uses light energy to make carbohydrates from carbon dioxide and water. </li></ul>

22.
Energy Production, continued <ul><li>Mitochondria </li></ul><ul><li>Mitochondria are cell organelles that use energy from organic compounds to make ATP (Adenosine Triphosphate – the main energy source for cells). </li></ul>

23.
Mitochondrion

24.
Summary <ul><li>The cytoskeleton helps the cell move, keep its shape, and organize its parts </li></ul><ul><li>In the cytoplasm, ribosomes use the RNA messages to assemble proteins. </li></ul><ul><li>The endoplasmic reticulum and Golgi apparatus are organelles involved in preparing proteins for extracellular export. </li></ul>

25.
Summary, continued <ul><li>Vesicles help maintain homeostasis by storing and releasing a variety of substances as the cell needs them. </li></ul><ul><li>The energy for cellular functions is produced by chemical reactions that occur in the mitochondria and chloroplasts. </li></ul>