The Cell

1. The Cell

5. NUCLEUS • Houses genetic material (DNA) • Controls all cellular activities

6. NUCLEAR MEMBRANE • Regulates what substances move in and out of the nucleus

7. NUCLEOLUS • Produces ribosomes

8. CHROMATIN • Chromosomes • Contains info for protein synthesis

9. CELL (PLASMA) MEMBRANE • Regulates movement of substances in and out of cell; selectively permeable • Site of much biological activity

10. CYTOPLASM • Holds organelles in place • Site of many cellular activities

11. RIBOSOMES • Sites of protein synthesis • Attached to ER or scattered in cytoplasm

12. ENDOPLASMIC RETICULUM • Transports molecules from one cell part to another

13. ROUGH ER Studded with ribosomes Protein synthesis SMOOTH ER No ribosomes Lipid production, absorption of fats, metabolism of drugs

15. GOLGI BODY • Refines, packages, and delivers proteins via vesicles to appropriate destinations

16. LYSOSOMES • Contain digestive enzymes to rid the cell of unnecessary material

17. PEROXISOMES • House enzymes that catalyze a variety of biochemical reactions - synthesis of bile - decomposition of certain lipids and biochemicals - detoxification of alcohol

18. MITOCHONDRIA • Make energy for the cell (ATP)

19. CYTOSKELETON • Form framework of cytoplasm or cell • Structure and support • Made of microtubules and microfilaments

20. MICROFILAMENTS Part of cytoskeleton Provide cell motility (movement) Structure and shape MICROTUBULES Part of cytoskeleton Cell motility Structure and shape Make up centrioles Make up cilia and flagella

21. CENTRIOLES • Distribute chromosomes to newly forming cells • Made of microtubules • Aid in cell reproduction

22. CILIA/FLAGELLA • Cilia – hair-like extensions that produce waves of motion to moves fluids • Flagella – tail-like extension that moves cells

23. VACUOLES • Storage of excess food, waste, worn out organelles, or other materials

24. Stained Cheek Cell cytoplasm nucleus cell membrane

25. III. VITAL CELL PROCESSES • Cells are the basic building blocks of the human body. • All systemic functions take place at the cellular level. • Some of the most important processes that occur within the cell are homeostasis, cell division, and protein synthesis.

26. A. HOMEOSTASIS • Maintained by the cell (plasma) membrane • The c.m. regulates homeostasis by controlling what enters and leaves the cell. • How does the c.m. do this?

27. By being selectively permeable • Selective permeability • molecules will move freely through the membrane if 1. they are small enough to fit through pores (water, sugars, ions) OR 2. they can dissolve in the fatty portion of the membrane

29. Cell Membrane Structure • c.m. is structured in such a way that it can carry out its main function; “form = function” • Phospholipid Bilayer phosphate 2 layers + 2 fatty acid chains

30. water Heads - polar Phospholipid molecule water Tails – non-polar Why two layers?

31. How does this work? • The heads (polar) allow cells to interact with aqueous (watery) environment inside and outside the cell • The tails (nonpolar) avoid water; stop water soluble particles from entering or leaving the cell • This equals selective permeability

32. What does the c.m. do? • Why is this important? • Particles within substances move naturally on their own (kinetic energy) • As they become more numerous or concentrated, they bump into each other. • This makes the particles move from where they are more to where they are less - diffusion

33. Diffusion – the movement of particles from an area of high concentration to an area of low concentration until equally distributed • Because of diffusion, particles are constantly being moved across the c.m. - Can all particles move across? - Why or why not?

35. http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.htmlhttp://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.html http://www.northland.cc.mn.us/biology/Biology1111/animations/transport1.html http://physioweb.med.uvm.edu/diffusion/MultiNoMembPages.htm

36. B. CELL DIVISION • All cells come from pre-existing cells • A cell reproduces only through cell division Cell Division (Mitosis) - cell division: cell reproduction - occurs in all body cells for normal growth, repair, and healing

37. Cell Cycle - cell cycle: the life of a cell - differs in length from one type of cell to another - two general periods 1. Interphase – growth 2. Mitosis – division - p. 66, fig. 3.21

39. - phases of the cell cycle are very complex - checkpoints control the cell cycle - i.e. the restriction checkpoint determines a cell’s fate (continues in cell cycle, stops dividing, or dies) - the cell cycle is highly regulated; too frequent = cancer, too infrequent, wounds cannot heal

40. - Cells do not normally divide continually; Hayflick limit - a cell knows when to stop dividing because of telomeres: chromosome tips that shorten with each division telomere

41. - Interphase consists of three parts 1. G1 – fast cell growth; metabolism 2. S – DNA synthesis; chromosomes copy 3. G2 – second growth phase; cell prepares itself for mitosis

42. - there are four parts to mitosis 1. prophase 2. metaphase 3. anaphase 4. telophase - by the end of division the duplicated chromosomes, nucleus, and cyto- plasm have been successfully divided - two new cells genetically identical to the original

43. Interphase Mitosis Prophase Metaphase AnaphaseTelophase

44. Prophase

45. Interphase

46. Anaphase

47. Metaphase

48. Telophase

49. http://www.bio.davidson.edu/misc/movies/MITOSIS.MOV http://video.google.com/videoplay?docid=-4760841506776651007&vt=lf&hl=en http://video.google.com/videoplay?docid=4045285854844480169&q=mitosis+video&hl=en http://www.youtube.com/watch?v=iHF422aDh1o http://www.youtube.com/watch?v=uSxomsXZVTo&feature=related

50. C. PROTEIN SYNTHESIS • Within the nucleus of all our cells are 46 chromosomes. • The chromosomes are made of DNA. • The chromosomes (DNA) are divided into segments called genes. • Genes control all of our traits. • How??