Cells

1. Cells

2. Since every living thing is made of cells, does that mean bigger organisms (like whales or elephants) have bigger cells? • Not really! • All organisms, no matter how tiny or how large are composed of cells. • There are different TYPES of cells (ex. Skin, bone, muscle, nerve), but all cells of a particular type are essentially the same size. • Therefore, the difference in cells in large vs. small organisms is the NUMBER of cells, not the SIZE!

3. How Were Cells Discovered? • New technologies lead to new discoveries • Robert Hooke - invented the first microscope and was the first to observe and name the small units that make up organisms. He called those small units cellsbecause of the appearance of the structures in the dead cork he observed.

4. How Were Cells Discovered? • Anton van Leeuwenhoek - improved the microscope and procedures for observing cells. He was able to clearly see living cells when observing the scrapings from his teeth.

5. Fill It In … Cells observed by … • Hooke: • Leeuwenhoek:

6. The Cell Theory Through the cooperative efforts of many individual scientists, a unifying cell theorydeveloped: • All organisms are made of cells • Cells are the structural & functional units of organisms • Cells come from pre-existing cells

7. The Cell Theory

8. Are all cells alike? Two main types of cells …. Prokaryotic vs Eukaryotic Cells

9. Prokaryotic Cells • Simplesttype of cell • Includes only bacteria. • Structure of a prokaryotic cell • No nucleus • No membrane-bound organelles • Includes: circular chromosome (DNA), plasmids (smaller rings of DNA, and ribosomes

10. Prokaryotic Cells- MYP • Thought to have a symbiotic relationship with Eukaryotic Cells • Nucleus • Mitochondria • Chloroplasts

11. Eukaryotic Cells • More complexthan prokaryotic cells • Includes protist cells, fungi cells, plant cells, and animal cells (i.e. - everything EXCEPT bacteria cells) • Structure of a eukaryotic cell • Chromosomes contained within a nucleus • In addition to ribosomes contains membrane-bound organelles Cells :)

12. Fill It In …

13. Check Yourself! • Who first to observed dead cells? Who first to observed living cells? • What are the two main types of cells? • How is the location of the DNA different in prokaryotic and eukaryotic cells?

14. Check Yourself! • Who first to observed dead cells? HOOKE Who first to observed living cells?LEEUWENHOEK • What are the two main types of cells? • How is the location of the DNA different in prokaryotic and eukaryotic cells? • What is cell specialization? • In cells, form relates to ________________.

15. Check Yourself! • Who first to observed dead cells? HOOKE Who first to observed living cells?LEEUWENHOEK • What are the two main types of cells? PROKARYOTIC & EUKARYOTIC • How is the location of the DNA different in prokaryotic and eukaryotic cells? • What is cell specialization? • In cells, form relates to ________________.

16. Check Yourself! • Who first to observed dead cells? HOOKE Who first to observed living cells?LEEUWENHOEK • What are the two main types of cells? PROKARYOTIC & EUKARYOTIC • How is the location of the DNA different in prokaryotic and eukaryotic cells? EUKARYOTIC CELLS KEEP THE DNA INSIDE A NUCLEUS • What is cell specialization? • In cells, form relates to ________________.

17. What do cells share?Structures found in ALL cells

18. DNA/Chromosome(s) • DNA organized as chromosome(s).DNA directs cell activity

19. Cytoplasm Cytoplasm is the “filling” of the cell and is made of up to 90% water. Water provides the necessary environment for all the chemical reactions the cell needs

20. Ribosomes Ribosomes are organelles that are the site of protein synthesis. Proteins are essential for enzymes, structure, and communication Uses DNA code to synthesize proteins

21. Cell Membrane • Also called the Plasma Membrane

22. Fill It In … 4 structures found in ALL cells: 1. 2. 3. 4.

23. Cell Membrane Composed of a phospholipid bilayer with embedded proteins. The fluid mosaic model describes the structure of the cell membrane

24. Cell Membrane Fluid - individual phospholipids and proteins can move past each other; they are not fixed in one position Mosaic - the membrane has more than one type of molecule (phospholipids & proteins)

25. Cell Membrane- MYP • Flexible/strong barrier • Some proteins from channel or pumps to allow things to go in and out of the cell • Carbohydrates are attached to membrane • These are used as chemical identification markers for the cell

26. Functions of the Cell Membrane • Selectively permeable - regulates what enters and leaves the cell. This helps maintain homeostasis • Gives the cell (cytoplasm) shape

27. Fill It In … The cell membrane is also called … And is S____________ P_____________

28. Structures (organelles) found in EUKARYOTIC cells

29. Fill It In … Organelle means …

30. 1. Nucleus • Nucleus - surrounds the chromosomes for additional protection; is made of a phospholipid bilayer

31. Nucleus- MYP • Surrounded by nuclear envelope (lipid bilayer) • Nuclear pores • Chromatin- DNA bound to proteins • Chromosomes are condensed chromatin • Nucleolus- dense region where ribosomes are synthesized

32. 2. Mitochondria • Mitochondria - site of cellular respiration which produces cell energy (ATP) • Active cells (muscle) -> hundreds of mitochondria • Inactive cells (fat) -> few mitochondria • Structure contains folded membranes which increases surface area allowing more space for more reactions • (MYP)-inherited through the ovum

33. Vacuoles - store food, waste or water to be used inside the cell or excreted from the cell. Size differs in plant vs. animal cells Much, much larger in plant cells … why? 3. Vacuole

34. Lysosomes - contain digestive enzymes which digest food contained in vacuoles as well as old or damaged cell parts (contain lipid bilayer) 4. Lysosomes

35. 5. Endoplasmic Reticulum (ER) • ER - a series of interconnected folded membranes that function in modifying (changing) proteins, detoxification of alcohols, and communication

36. ER (MYP) Lipid components of the cell membrane are made here Proteins and other material are exported or inserted into the cell membrane

37. Two Types of ER • Rough ER • Covered in ribosomes • Modify proteins

38. Two Types of ER • Smooth ER • Lacks ribosomes • Detoxification

39. 6. Golgi Complex • Golgi Complex- packages materials for export from cells • (MYP)- Modify, Sort, and Package • “finishing touches”

40. Plant Cellversus Animal Cell

41. Chloroplasts - organelles full of chlorophyll that are the site of photosynthesis which produces sugars (C6H12O6) Composed of folded membranes for more surface area Structures found ONLY in plant and plant-like cells

42. Cell Wall - provides extra support, protection, and shape for the cell Found outside the cell membrane and made of cellulose Structures found ONLY in plant and plant-like cells

43. Structure found ONLY in animal cells • Centrioles -organelle that helps with cell division in animal cells

44. Cytoskeleton (MYP) Protein filaments to help maintain shape May help with movement (amoeba) Microtubules help with cell division (pulling the chromosomes)

46. Fill It In … Summary of structure/function: Nucleus - Mitochondria - Vacuole - Lysosome - ER - Golgi - Chloroplast -

47. Fill It In …

48. Check Yourself! • What four structures are found in all cells? • What is the function of the mitochondria? • What is the function of the ribosome? • What term refers to small cell structures? • What two structures are found in plant and plant-like cells?

49. Check Yourself! • What four structures are found in all cells? DNA, CYTOPLASM, RIBOSOMES, CELL MEMBRANE • What is the function of the mitochondria? • What is the function of the ribosome? • What term refers to small cell structures? • What two structures are found in plant and plant-like cells?

50. Check Yourself! • What four structures are found in all cells? DNA, CYTOPLASM, RIBOSOMES, CELL MEMBRANE • What is the function of the mitochondria? CELLULAR RESPIRATION/MAKE ENERGY FOR THE CELL • What is the function of the ribosome? • What term refers to small cell structures? • What two structures are found in plant and plant-like cells?