Cells are the basic building blocks of life. They can be single-celled organisms or part of multicellular organisms. Cells are classified based on whether they have a nucleus or not. Prokaryotic cells like bacteria lack a nucleus, while eukaryotic cells like human and plant cells have a nucleus and membrane-bound organelles. The nucleus controls cell activities and contains DNA. Organelles like the mitochondria and chloroplasts allow cells to perform essential functions like respiration and photosynthesis. Cells reproduce through fission in prokaryotes and mitosis or meiosis in eukaryotes.

1. Basic Cell Structure

2. Cells Basic building blocks of life Understanding of cell morphology is critical to the study of biotechnology

3. Cell Smallest living unit of an organism Grow, reproduce, use energy, adapt, respond to their environment

4. Cell Many cannot be seen with the naked eye A cell may be an entire organism or it may be one of billions of cells that make up the organism

5. Cells Divided and classified in many ways One common classification method is the presence or absence of a cell necleus

6. Nucleus Relatively large structure with a cell Directs cell activities Some simple single celled organisms lack a nucleus

7. Nucleus Prokaryotes – have no nucleus Eukaryotes – have a nucleus

8. Prokaryotes Single celled organism Kingdom Monera Lacks a cell nucleus Internal structure is less organized than other cells

9. Prokaryotes Genetic info needed is within the cell Two most common – blue green bacteria and true bacteria

10. Blue green bacteria Have ability to produce their own food like plants Most bacteria get their food from other sources

11. Prokaryotes Less complex than eukaryotes Still have many of the basic internal characteristics

12. Common prokaryote structures Cytoplasm Chromosomal material Cell membrane and wall Ribosomes Some have flagellum for mobility

13. Eukaryotes Organism made up of cells that have a nucleus May be single celled – Kingdom Protista May have billions of cells like plant and animal kingdoms

14. Eukaryotes Single celled eukaryotes include paramecia, euglena, and diatoms

15. Eukaryotes Typically are highly organized Infinite number of shapes and purposes

16. Eukaryotes Human body has at least 85 different cell types All eukaryotes have a number of structures in common

17. Common structures Organelles – smaller parts of the cell with specific funtions Cell membrane – acts as a gatekeeper

18. Cell membrane Controls what enters and leaves the cell Plants, algae and bacteria typically have a tough outer structure known as a cell wall

19. Cell wall Provides additional structure and protects the cell from pressure caused by movement of water Animal cells do not have walls

20. Cytoplasm Organelles are surrounded by a jelly like substance Primary component is water

21. Nucleus Largest and most identifiable part of the cell

22. Other organelles Ribosomes Mitochondria Golgi bodies Endoplasmic reticulum

23. Other organelles Lysosomes Vacuoles Chloroplasts in plants

24. Nucleus Brain of the cell Site of much of the manipulation done in biotechnology

25. Nucleus Controls activity of the cell Round or oval structure Typically found in the middle of the cell Appears darker than surrounding material

26. Nucleus Surrounded by a membrane that controls passage of materials in and out of the area

27. Nucleus Contains DNA DNA is located on chromosomes Most organisms are diploid – have tow chromosomes for each trait

28. Diploid Humans – 23 pair Goldfish – 90 chrms, 45 pair

29. Cytoplasmic Organelles Organelles are required for proper cell function Ribosome – make proteins for cellular use and communication May be attached to endoplasmic reticulum

30. Endoplasmic reticulum Layered membraneous Make and transport proteins

31. Vacuole Large organelle, without specific shape Store waste or raw materials used in synthesis of proteins

32. Golgi Bodies Golgi apparatus Similar to endo. Ret. Look like a thick elastic band that has been folded several times

33. Golgi Bodies Adds modifications to unfinished proteins Makes lysosomes

34. Lysosome Small round Store enzymes that break down food into chemical compounds Destroy cell organelles and the cell itself

35. Mitochondria Energy factories Rod shaped Change food into molecules that can be used for energy

36. Mitochondria Contain DNA Can replicate themselves

37. Chlorplast Found in plants and some other organisms Contain chlorophyll

38. Cellular processes Respiration Osmosis Diffusion Photosynthesis

39. Respiration Cells break down carbohydrates and other molecules to produce energy Oxidation of glucose is one of most common forms

40. Respiration Breaking down of sugar into water, carbon dioxide, and energy Energy is used to do the work of the cell

41. Osmosis & Diffusion Transport of raw materials, wastes, and synthesized materials out of the cell

42. Diffusion Movement of molecules, especially gases and liquids from areas of high concentration to areas of low concentration

43. Osmosis Specific type of diffusion Movement of water through a membrane from areas of high concentration to areas of low concentration

44. Equilibrium Diffusion and osmosis happen to enable a cell to reach equilibrium

45. Cellular reproduction Three ways Fission Mitosis Meiosis

46. Fission Prokaryotes Cell grows larger and makes a second copy of its DNA At some point the cell membrane divides the cell by the growth of a transverse septum

47. Fission Two new cells are formed as the division grows inward from either side of the cell Two cells now called “daughter cells” Sometimes known as “binary fission”

48. Mitosis Eukaryotes Requires 6 stages Interphase, prophase, metaphase, anaphase, telophase, cytokinesis

49. Mitosis Creates cells that are identical to the original cell. Have the entire compliment of chromosomes existing in pairs - diploid

50. Meiosis Division of sex cells Stages of Meiosis I: Interphase I, prophase I, metaphase I, anaphase I, telophase I, cytokinesis I

51. Meiosis Meiosis II Interphase II, prophase II, metaphase II, anaphase II, telophase II, cytokinesis II

52. Meiosis Each cell receives one chromosome from each pair randomly Resulting cells have half the normal number of Chromosomes - haploid