Cell Diversity

1. Cell Diversity

2. Cell Diversity • Cells of different organisms and even cells within the same organism are VERY diverse in terms of shape, size, and internal organization. • There are at least 200 different types of cells, ranging from flat cells to branching cells to round cells to rectangular cells!

3. Recurring Theme • One major theme in biology that occurs again and again is that form follows function! • In other words, a cells function influences its physical features.

4. Cell Shape • The diversity in cell shapes reflects the different functions of the cells • Compare the cells below. How does the nerve cell’s shape help it? The skin cell’s?

5. Cell Size • Cells differ in their size as well as their shape • Some nerve cells that extend from a giraffe’s spinal cord to the foot can be 2 m long! • Most cells are about 1/500th the size of the period at the end of a sentence.

6. Cell Size • The size of a cell is limited by the relationship of the cell’s outer surface are to its volume aka surface area-to-volume ratio

7. Cell Volume • As a cell grows, the volume increases much faster than the surface area • Important because the materials needed by a cell and the wastes produced must pass in and out of the cell through its surface • If a cell were to become very large, the volume would increase more than the surface area, so materials wouldn’t be able to enter or leave quickly enough

8. Cell Volume

9. Basic Parts of A Cell • Plasma Membrane • Cytoplasm • Control Center

10. Plasma Membrane • The cell’s outer boundary • Covers cell’s surface and acts as a boundary • Cannot be seen through a light microscope

11. Cytoplasm • The region of the cell that is within the plasma membrane and includes the fluid, the cytoskeleton, and all of the organelles • The cytosol is the part of the cytoplasm that includes molecules and small particles, but not membrane bound organelle

12. Control Center • Cells carry coded information in the form of DNA for regulating functions and reproducing themselves. • Some DNA floats freely in cells, other cells have a nucleus housing the DNA • Nucleus is a membrane-bound structure

13. Two Basic Cell Types • Prokaryotes • Lack membrane bound organelles • Have a nucleoid region where DNA is located • Bacteria and Archaea • Eukaryotes • Organisms made up of one or more cells and have membrane bound organelles • Much larger than prokaryotic cells

14. Prokaryotic Cell

15. Eukaryotic Cell

16. Cellular Organization • In multicellular organisms, cells organize into tissues, which organize into organs, then organ systems • Colonial organisms (colonies) are a groups of identical cells that live together in a connected group. These aren’t multicellular because their activities aren’t coordinated

17. Animal Cell Cytoplasm Nucleolus Nucleus Cell Membrane

18. Eukaryotic Cell Organelles and Function • Nucleus • Nickname: “The Control Center” • Function: holds the DNA • Parts: • Nucleolus: dark spot in the middle of the nucleus that helps make ribosomes

19. Animal Cell Cytoplasm Nucleolus Ribosomes Nucleus Cell Membrane

20. Eukaryotic Cell Organelles and Function • Ribosomes • Function: makes proteins • Found in all cells, prokaryotic and eukaryotic

21. Eukaryotic Cell Organelles and Function • Endoplasmic Reticulum (ER) • Nickname: “Roads” • Function: The internal delivery system of the cell

22. Animal Cell Cytoplasm Nucleolus Ribosomes Nucleus Cell Membrane Smooth Endoplasmic Reticulum Rough Endoplasmic Reticulum

23. Endoplasmic Reticulum • 2 Types: • Rough ER: • Rough appearance because it has ribosomes • Function: helps make proteins, that’s why it has ribosomes • Smooth ER: • NO ribosomes • Function: makes fats or lipids

24. Animal Cell Cytoplasm Ribosomes Nucleolus Nucleus Cell Membrane Smooth Endoplasmic Reticulum Rough Endoplasmic Reticulum Golgi Complex

25. Eukaryotic Cell Organelles and Function • Golgi Complex • Nickname: The shippers • Function: packages, modifies, and transports materials to different location inside/outside of the cell • Appearance: stack of pancakes

26. Animal Cell Cytoplasm Nucleolus Ribosomes Nucleus Cell Membrane Smooth Endoplasmic Reticulum Rough Endoplasmic Reticulum Golgi Bodies

27. Eukaryotic Cell Organelles and Function • Lysosomes: circular, but bigger than ribosomes) • Nickname: “Clean-up Crews” • Function: to break down food into particles the rest of the cell can use and to destroy old cells

28. Animal Cell Cytoplasm Nucleolus Ribosomes Nucleus Cell Membrane Mitochondria Smooth Endoplasmic Reticulum Rough Endoplasmic Reticulum Golgi Bodies

29. Eukaryotic Cell Organelles and Function • Mitochondria • Nickname: “The Powerhouse” • Function: Energy formation • Breaks down food to make ATP • ATP: is the major fuel for all cell activities that require energy

31. Animal Cell Cytoplasm Nucleolus Ribosomes Nucleus Cell Membrane Mitochondria Smooth Endoplasmic Reticulum Rough Endoplasmic Reticulum Golgi Bodies

32. Now let’s talk about structures only found in PLANT Cells!!

33. Plant Cell Vacuole Cell Membrane

34. Eukaryotic Cell Organelles and Function • Vacuoles • Function: stores water • This is what makes lettuce crisp • When there is no water, the plant wilts

35. Plant Cell Vacuole Chloroplasts Cell Membrane

36. Eukaryotic Cell Organelles and Function • Chloroplasts • Function: traps energy from the sun to produce food for the plant cell • Green in color because of chlorophyll, which is a green pigment

37. Chloroplasts

38. Plant Cell Vacuole Chloroplasts Cell Membrane Cell Wall

39. Eukaryotic Cell Organelles and Function • Cell Wall • Function: provides support and protection to the cell membrane • Found outside the cell membrane in plant cells

40. Plant Cell Cytoplasm Smooth ER Vacuole Ribosomes Chloroplasts Cell Membrane Cell Wall Nucleolus Golgi Bodies Nucleus Mitochondria Rough ER

41. Comparing Plant and Animal Cells