1. Unit 4: Cell/Cell Transport 8A Miss Sabia

2. Essential Question 1.What is a cell? 2.What scientific contributions led to the development of the cell theory?

3. Do Now Write down any structures you recognize in this cell.

4. Cell A structure within a living thing that has a definite boundary enclosing the material inside The basic unit of structure and function in a living thing

5. How did people discover cells? The invention of the microscope made it possible for people to discover and learn about cells! Microscope : an instrument that makes small objects look larger – A simple microscope has only one lens – A compound microscope is a light microscope that has more that one lens Late 1590’s (approx)

6. Robert Hooke English scientist and inventor, 1665 One of the 1 st people to observe cells Observed a cork under a microscope, called the little structures cells because they reminded him of tiny rooms

7. Anton van Leeuwenhoek Made his own lenses, then used them to construct his own simple microscopes Studied pond water—found little animals in the water (one-celled organisms) Looked at teeth scrapings—was the 1 st scientist to see bacteria!

8. Soon enough… Numerous observations made it clear that cells were the basic units of life 1838: Matthais Schleiden said all plants are made of cells 1839: Theodor Schwann stated that all animals are made of cells 1885: Rudolf Virchow concluded that new cells could be produced only from the division of existing cells

9. Cell Theory 1.All living things are made of cells 2.Cells are the basic unit of structure and function in living things 3.All cells are produced from existing cells

10. Essential Question How are cells organized?

11. Prokaryotes v. Eukaryotes No nucleus Smaller and simpler Contain cell membrane and cytoplasm Ex: bacteria Carry out every activity associated with life Have a nucleus Have cell membrane and cytoplasm Have organelles Many are large, multicellular organisms Ex: plants, animals, fungi

12. Organelles Organelles : specialized structures that perform important cellular functions “little organs”

13. Cell Membrane Thin, flexible barrier around the cell Semi-permeable —only lets certain materials in/out Separates the cell from its external environment Supports and protects the cell More to come on this later…

14. Cell Wall Plant cells only! Supports and protects the cell Prevents plant cell from bursting due to turgor pressure (from water) Made of cellulose (a tough carbohydrate fiber)

15. Cytoplasm Material inside the cell membrane— not including the nucleus Thick, fluid, gel-like substance

16. IN THE NUCLEUS…

17. Nucleus “brain” or “control center” Contains cell’s genetic material (DNA) and controls the cell’s activities Chromatin : DNA bound to protein Chromosome : condensed chromatin

18. Nucleolus Small, dense region within the nucleus Makes ribosomes

19. Nuclear Envelope Surrounds and protects the nucleus Has thousands of pores—allow material to move in/out

20. CYTOSKELETON…

21. Cytoskeleton Network of protein filaments that helps the cell to maintain its shape Also involved in many forms of cell movement microtubules : hollow tubes of protein about 25 nm; maintain cell shape and allow organelles to move on them like tracks Microfilaments : long, thin fibers that aid in movement and support; 7 nm

22. IN THE CYTOPLASM…

23. Ribosomes Make proteins

24. Do Now Write the function of the following organelles: – Nucleus – Cell membrane – Ribosome – Cell wall

25. Endoplasmic Reticulum An internal membrane structure Assembles components of the cell membrane and modifies proteins Rough ER —protein synthesis; contains ribosomes on its surface Smooth ER —lipid synthesis, among other tasks

26. Golgi Apparatus Golgi body, Golgi complex Enzymes in the Golgi attach carbs and lipids to proteins. Proteins are then sent to their final destinations Golgi receives proteins from ER

27. Lysosomes Small Filled with enzymes that break down carbs, lipids, and proteins into particles that can be used by the rest of the cell Also break down old organelles Remove debris to de-clutter the cell

28. Vacuoles Store materials like water, salt, and proteins Central Vacuole (in plants): filled with liquid, makes it possible for plants to support heavy structures like leaves and flowers When vacuoles are used for transport, we call them vesicles

29. Chloroplast Only in plants! Use energy from sunlight to make food (photosynthesis) Contain green pigment chlorophyll in photosynthetic membranes

30. Structure of a Chloroplast

31. (Mighty) Mitochondria Use energy from food to make high energy compounds that the cell uses for growth, development, and movement “powerhouse”

32. Structure of a Mitochondrion

33. Summary

34. Coming soon to a theater near you! Prokaryotes v. eukaryotes Organelles Cell membrane State Lab—Diffusion Through a Membrane

35. Organelle Project