1. Cells Made Simple Biology 11 Ms. Bowie

2. Cells Smallest living unit Most are microscopic

3. Principles of Cell Theory All living things are made of cells Smallest living unit of structure and function of all organisms is the cell All cells arise from preexisting cells (goodbye spontaneous generation)

4. Cell Size

5. Cells Have Large Surface Area-to-Volume Ratio

6. Characteristics of All Cells A surrounding membrane Protoplasm – cell contents in thick fluid Organelles – structures for cell function Control center with DNA

7. Cell Types Prokaryotic Eukaryotic There are 2 main types of cells

8. Prokaryotic Cells First cell type on earth Cell type of Bacteria and Archaea

9. Prokaryotic Cells No membrane bound nucleus Nucleoid = region of DNA concentration Organelles lack membranes too

10. Eukaryotic Cells Nucleus bound by membrane Include fungi, protists, plant, and animal cells They contain many organelles Protozoan

11. Representative Animal Cell

12. Representative Plant Cell

13. Organelles Carry out all cellular functions

14. Plasma Cell Membrane Holds all contents of the cell inside Controls what enters & leaves the cell Structure is a lipid bilayer

15. Phospholipids The membrane parts are “polar”. –Hydrophylic (water loving) head –Hydrophobic (water fearing) tail

16. Movement Across the Plasma Membrane A few molecules move freely across the membrane. They are: –Water, Carbon dioxide, Ammonia, Oxygen Carrier proteins must help other substances cross the membrane: –The Proteins are embedded in lipid bilayer

18. Cell Walls Found in plants, fungi, & many protists The cell wall is missing in animal cells Surrounds plasma membrane

19. Cell Wall Differences Plants – made mostly of cellulose Fungi – made mostly of chitin

20. Cytoplasm A thick fluid containing the organelles The cytoplasm holds: –Interconnected filaments & fibers –Fluid = cytosol –Organelles – storage substances

21. Cytoskeleton Consists of filaments & fibers Made of 3 fiber types –Microfilaments –Microtubules –Intermediate filaments 3 functions: – mechanical support – anchor organelles – help move substances

22. A = actin, IF = intermediate filament, MT = microtubule

23. Cilia & Flagella Provide ability to move things Cilia (hair-like) –Short –Used to move substances outside human cells Flagella –Whip-like extensions –Found on sperm cells

24. Centrioles Pairs of microtubular structures Play a role in cell division (reproduction of new cell – remember meiosis and mitosis?)

25. Membranous Organelles Tiny organ found inside cytoplasm They are bound by membranes

26. Nucleus Control center of cell Double membrane Contains –Chromosomes (DNA) –Nucleolus

27. Nuclear Envelope (Membrane) Separates nucleus from rest of cell Double membrane Has pores just like the cell membrane.

28. DNA DNA stands for deoxyribonucleic acid The hereditary material Holds the entire blueprint for the organism Contained within chromosomes

29. Nucleolus Most cells have 2 or more Directs synthesis of RNA Creates ribosomes

30. Endoplasmic Reticulum Helps move substances within cells It’s a Network of interconnected membranes Two types exist in cells: –Rough endoplasmic reticulum –Smooth endoplasmic reticulum

31. Rough Endoplasmic Reticulum Ribosomes attached to surface –They make proteins –Not all ribosomes attach to rough ER May modify proteins from ribosomes

32. Smooth Endoplasmic Reticulum No attached ribosomes (so it is smooth!) Has enzymes that help build molecules: –Carbohydrates –Lipids

33. Golgi Apparatus (or Body) Packaging & shipping station of cell

34. Golgi Apparatus Function 1. Molecules come in vesicles 2. Vesicles fuse with Golgi membrane 3. Molecules may be modified by Golgi

35. Golgi Apparatus Function (Continued) 4. Molecules pinched-off in separate vesicles 5. Vesicle leaves Golgi apparatus 6. Vesicles may combine with plasma membrane to expel the contents (called exocytosis)

37. Lysosomes Contain digestive enzymes Functions –Aid in cell renewal –Break down old cell parts –Digests invaders

38. Vacuoles Membrane bound storage sacs More common in plants than animals Holds: –Water –Food –wastes

39. Mitochondria Have their own DNA Bound by double membrane

40. Mitochondria Break down fuel molecules ( cellular respiration) –Glucose –Fatty acids Release energy –ATP

41. Chloroplasts Solar energy capturing organelle

42. Photosynthesis Takes place in the chloroplast Makes cellular food – glucose Converts sunlight into sugars!

43. Review of Eukaryotic Cells