THE CELL

1. THE CELL

2. The Cell Theory • All organisms are made up of one or more cells. • The cell is the basic unit of structure and organization of organisms. 3. All cells come from pre-existing cells.

3. There are two basic cell types: Prokaryote

4. and Eukaryote

5. Compare the pictures!

6. How are they different? Question: Which is more complex? Add your answer to the table.

7. Eukaryote cells make and use organic molecules in their membrane-bound organelles What were the four organic molecules? • Carbohydrates • Proteins • Lipids • Nucleic acids

8. Section 7.1 Summary – pages 171-174 The membrane-bound structures within eukaryotic cells are called organelles. Each organelle has a very specific function that contributes to the survival of the cell. An Analogy! Just like all the parts of your anatomy have unique roles, i.e. fingers to grab, feet to walk, mouth to talk, eyelids to protect, etc. Huh?!

9. What are some of the organelles found in Eukaryote cells?

10. The Nucleus The control center of the cell

11. In the nucleus Nucleic acids are made from nucleotides through the process of _________ _______. DNA is kept inside the nucleus where it is safe DNA is useful as a pattern for making proteins. How? (see below…) RNA copies sections of the DNA and then travels outsidethe nucleus to ribosomes in the cytoplasm.

12. Answer these questions 4. Why do you think a cell keeps DNA in the nucleus but RNA is “allowed” to leave the nucleus? 5. When two nucleotides are bonded together, what molecule is released? 6. What is the process called that breaks the bond?

13. Ribosomes! • Protein Factories of the cell! • Ribosomes synthesize (make) proteins! (using the instructions on RNA) • Types • Free • Bound www.scripps.edu/chem/wong/rna.html

14. The Golgi and the Rough Endoplasmic Reticulum

15. The Golgi Apparatus and the Rough Endoplasmic Reticulum The “rough” ER is covered with ribosomes. Ribosomesassemble amino acids into proteins through the process of_____ _______. Vesicles bud from the ER and carry the proteins to the Golgi Apparatus Proteins are modified, and packaged into vesicles in the Golgi.

16. Now, The proteins can be transported anywhere inside or outside the cell. Note: proteins from the packaged into vesicles at the Golgi apparatus are usually secretory…

17. Comprehension Question What organelles are involved in making and “processing” proteins? • Summarize the functions of each organelle and give an analogy (to help you remember) for each one.

18. The Smooth Endoplasmic Reticulum

19. The Smooth Endoplasmic Reticulum It has no ribosomes It DOES NOT make proteins It makes lipids from fatty acids and glycerol through the process of condensation and stores the lipids Also, helps detoxify poisons (there is a lot of smooth ER in the liver, for instance)

20. Answer these questions 1. How is the rough ER different from the smooth ER? 2. What organelles are involved in making and “processing” proteins? 3. How will the stored lipid molecules be used by the cell?

21. The Chloroplast Only found in plant cells!

22. Inside the chloroplast Glucose, the main carbohydrate, is made from CO2 and H2O. (What elements?) What is this process called?

23. The mitochondria Found in all eukaryote cells

24. Inside the mitochondria is where glucose is broken down and used to make ATP cell energy What is this process called?

25. Answer these questions • How does the chloroplast work in plant cells? How does the mitochondria work in plant cells? • How do your cells use glucose? 9. Where do animal cells get glucose?

26. Lysosomes • Full of enzymes to: • Digest food particles • Destroy invaders (viruses etc.) • Clean up cell wastes

27. Other cell structures… • See next slide…

28. The cytoskeleton is made up of microtubules and microfilaments Gives shape and internal organization to the cell • Picture taken by Mr. Baughman • Blue =cell nucleus • Red = Actin microfilaments

29. The Cell Wall Only in plant cells! Provides extra support

30. Answer these questions 10. What organelles provide structure to the cell? 11. In what ways are plant cells different from animal cells? 12. Why do plant cells need a cell wall?

31. In your Journal… • Compare AND Contrast animal cells and plant cells using a table or Venn Diagram • See below for the important points (check yourself):

32. The Plasma Membrane

33. What does the plasma membrane do? It controls what enters and leaves the cell

34. It is semi-permeable (or selectively permeable) This means not everything gets through (it selects what gets through.)

35. What makes up a plasma membrane? • Phospholipids • Proteins • Carbohydrates • Cholesterol

36. Phospholipids Two lipid “tails” with a phosphate “head” The “tails” are nonpolar and hydrophobic (they hate water) The “head” is polar and hydrophilic (it loves water)

37. The phospholipids are arranged in a bilayer

38. The two layers of phospholipids form a sandwich

39. The lipid “tails” are inside the sandwichand the phosphate “heads” are outside

40. The hydrophobic “tails” keep polar (hydrophilic) molecules, ionic compounds and large substances from passing through

41. Cholesterol helps stabilize the phospholipids

42. Carbohydrate “antennae” help cells identify chemical signals and other cells

43. Transport proteins form channels or passageways

44. These allow substances the cell needs to enter And wastes to leave Animations: C:\Documents and Settings\BBAUGHMAN\Desktop\bio powerpoints\Chapter 07 BDOL IC C:\Documents and Settings\BBAUGHMAN\Desktop\bio powerpoints\Chapter 08 BDOL IC

45. The purpose of the plasma membrane is to maintain homeostasis and keep your cells safeActivity: The human plasma membrane

46. Answer these questions 13. What part of the phosopholipid molecule faces the outside of the cell? 14. Is this part hydrophobic or hydrophilic? 15. Why is the bilayer arrangement important? 16. Why do you need some cholesterol in your diet?

47. A few more questions 17. What part of the membrane helps chemical messengers (hormones) find the cell? 18. What pathway would molecules take through the membrane if they can’t pass through the phospholipid bilayer? 19. What is the overall purpose of the plasma membrane?

48. Transport across membranes: • Summary: • Passive Transport: NO energy needed! • Examples: • Diffusion • Osmosis • Facilitated diffusion—uses transport proteins. • Active Transport: Energy required!

49. Diffusion • Diffusion—movement of molecules or ions from higher to lower concentration • Concentration gradient— difference in concentrations between different areas. • In diffusion, substances move DOWN their concentration gradient • Facilitated diffusion—uses transport proteins. • Question: Are these processes active or passive? • http://www.indiana.edu/~phys215/lecture/lecnotes/lecgraphics/diffusion.gif • http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.html Activity: The human concentration gradient!

50. Osmosis • Review of Solutions: • 1. Solute: • 2. Solvent: • Osmosis= diffusion of water across a selectively permeable membrane. *Water moves from greater to lesser concentration of water. • Isotonic—concentration inside and outside is equal • Hypotonic—hypo= low (in solutes) compared to cell • Water rushes INTO cell • Hypertonic—hyper= high (in solutes) compared to cell • Water rushes OUT of cell • **Note: Hypertonic, hypotonic and isotonic always refer to solution OUTSIDE of the cell. TONIC = solute