2. Section 3: Parts the Cell

3. Definition of Cell A cell is the smallest unit that is capable of performing life functions.

4. 1.Organelle: membrane-bound structure within a cell that has a specific shape and function. a)“little organs” b)Examples: Nucleus, Mitochondria, Chloroplast Definition of Organelle

5. Structure and Function of Organelles 1.The Structure and Function of the following organelles will be discussed: –Cell Wall –Cell (Plasma) Membrane –Nucleus –Nuclear Envelope –Nucleolus –Ribosomes –Cytoplasm –Endoplasmic Reticulum –Golgi Apparatus –Vacuoles –Lysosomes –Mitochondria –Chloroplasts –Cytoskeleton –Centrioles –Cilia and Flagella

6. Surrounding the Cell

7. Cell Wall – Rock Wall around Burlington 1.Structure: rigid wall made up of cellulose (plants), proteins, carbohydrates, chitin (fungi) 2.Function: boundary around the plant cell, outside of the cell membrane that provides structure, support, and protection 3.Eukaryotic & Prokaryotic

8. Cell Membrane/Plasma membrane – Burlington City Limits Structure: Two layers of phospholipids and proteins Function: Regulates materials entering and exiting the cell

9. Inside the Cell

10. Nucleus – Burlington City Hall 1.Structure: Separated from cytoplasm by nuclear envelope; contains nucleolus; contains DNA 2.Function: Controls cells activities. Regulates DNA and RNA actions 3.Eukaryotic

11. Nucleus – Burlington City Hall

12. Nuclear Envelope – Walls & Doors of City Hall 1.Double layer of lipids surrounds nucleus 2.Regulates what enters or exits the nucleus

13. DNA – Burlington’s Laws & City Code 1.Structure: Made up of nucleotides, locked in the nucleus 2.Function: information how to make proteins a)Chromatin – unorganized DNA (normal state) b)Chromosomes – organized DNA (present before cell division)

14. 13

15. Chromosomes 1. Inside nucleus 2. Made of DNA 3. Contain instructions for traits & characteristics 4. 46 total in each cell**

16. Nucleolus – Burlington Mayor 1.Structure: inside the nucleus, separate from DNA 2.Function: Produces RNA and ribosomes, which are used to make all proteins 3.Eukaryotic

17. Ribosomes – Factories, Builders 1.Structure: not membrane-bound; consist of two subunits made of protein and RNA a)Found attached to rough ER or floating free in cytoplasm 2.Function: location of protein synthesis 3.Eukaryotic & Prokaryotic

18. Cytoplasm – All air, water, life that are in Burlington, except City Hall 1.Structure: gelatin-like fluid that lies inside the cell membrane except for nucleus a)A human cell system is approximately 75% water 2.Function: All cell contents that lie between the cell membrane and nucleus 3.Eukaryotic & Prokaryotic

19. Endoplasmic Reticulum – Roads & Sidewalks 1.Structure: a system of membranous tubules and sacs 2.Function: site of chemical reactions involving protein synthesis. Transportation route for proteins 3.Two types: a)Rough Endoplasmic Reticulum b)Smooth Endoplasmic Reticulum 4.Eukaryotic

20. Rough Endoplasmic Reticulum 1.Rough Endoplasmic Reticulum (rER): make large amounts of proteins to be exported from the cell or inserted into the cell membrane a)Ribosomes attached to the surface

21. Rough Endoplasmic Reticulum

22. Smooth Endoplasmic Reticulum 1.Smooth Endoplasmic Reticulum (sER): involved in the synthesis of lipids and breakdown of toxic substances a)Not covered with ribosomes

23. Golgi Apparatus – Post Office 1.Structure: stacked flat sacs 2.Function: receives proteins from the rER and distributes them to other organelles or out of the cell a)receives, processes, packages, and ships proteins 3.Eukaryotic

24. Golgi Apparatus – Post Office

25. Golgi Apparatus Function 1.Molecules come in vesicles 2.Vesicles fuse with Golgi membrane 3.Molecules may be modified by Golgi 4.Molecules pinched-off in separate vesicle 5.Vesicle leaves Golgi apparatus 6.Vesicles may combine with plasma membrane to secrete contents

27. Vacuoles & Vesicles – Grocery stores, water tanks 1.Structure: a sac of fluid surrounded by a membrane a)Very large in plants and very small in animals 2.Function: used for temporary storage of wastes, nutrients, and water 3.Eukaryotic

28. Vacuole

29. Lysosomes – Recycling Center 1.Structure: spherical organelles that contain hydrolytic enzymes a)Formed by the Golgi 2.Function: breaks digest down: a)food particles b)invading objects c)worn out cell parts (digestion) d)Transports undigested material to cell membrane for removal 3.Eukaryotic

30. Lysosomes – Recycling Center

31. Mitochondria – Power Plants 1.Structure: folded membrane within an outer membrane a)The folds of the inner membrane are called cristae 2.Function: Produces energy ATP through chemical reactions by breaking down fats and carbohydrates (glucose) a)A.K.A - cellular respiration 3.Eukaryotic

32. Mitochondria – Power Plants

34. Chloroplasts – Solar Panels 1.Structure: stacked sacs (thylakoids) that contain chlorophyll surrounded by a double membrane 2.Function: site of photosynthesis (converting sun and CO2 into glucose) 3.Eukaryotic

35. Photosynthesis –Restaurants 1.Takes place in the chloroplast 2.Makes cellular food – glucose

36. Cytoskeleton – Wood, cement, steel beams 1.Structure: a network of thin, fibrous elements made up of microtubules and microfilaments 2.Function: Provide support and structure for the cell. Anchors organelles 3.Eukaryotic

37. Microfilaments and Microtubule 1.Helps to maintain shape of the cell. 2.Aid in cell division (mitosis and meiosis)

38. Centrioles – Cummings High vs. Western High 1.Structure: composed of microtubules arranged in a ring a)Exist in pairs 2.Function: help divide the cell during cell division (mitosis) 3.Eukaryotic

39. Centrioles Short tubes necessary for cell division (reproduction)

40. Cilia & Flagella – Cars or bicycles 1.Used for movement (animal cells only) 2.Cilia a)Many short fibers b)Used to move substances outside human cells 3.Flagella a)1 long fiber b)Whip-like extensions c)Found on sperm cells

41. Cell Parts Analogy Homework 1.Create an analogy (besides the city analogy) for the cell and its parts 2.Possible ideas: a)Stadium b)School c)Country d)Restaurant e)House f)Mall

42. Stadium Example: 1.Cell membrane: wall of stadium, gates 2.Cytoplasm: everything inside the stadium. 3.Nucleus: the control room for the stadium. 4.Etc…

43. Plant Cells vs. Animal Cells 1.Animal cells are very similar to plant cells except for the following major differences: a)Animal cells do not contain chloroplasts b)Animal cells are not surrounded by cell walls c)The vacuoles in plants are much larger than those of animals

44. Animal Cell

45. Plant Cell

46. Comparison of Cells

47. Microscope Pictures of a Plant Cell and an Animal Cell Elodea Human Cheek Cells

49. Section 4: Functions of Cells

50. Functions of the Cell 1.Each living cell carries out the tasks of: a)digesting food b)transforming food into energy c)getting rid of wastes d)reproducing.

51. Functions of the Cell - Exocytosis 1.Materials are exported out of the cell via secretory vesicles. In this process, the Golgi complex packages macromolecules into transport vesicles that travel to and fuse with the plasma membrane. 2.This fusion causes the vesicle to spill its contents out of the cell. 3.Important in expulsion of waste materials out of the cell and in the secretion of cellular products such as digestive enzymes or hormones.

52. Exocytosis

53. Exocytosis

54. Functions of the Cell - Endocytosis 1.Process by which materials move into the cell. 2.In phagocytosis or “cellular eating,” the cell’s plasma membrane surrounds a macromolecule and buds off to form a food vacuole. 3.Then it fuses with a lysosome whose hydrolytic enzymes digest the “food” inside.