Cell Structures

1. Cell Structures By: Amber Tharpe

2. Invention of the microscope was important for the discovery and study of cells

3. Cell Theory • All living things are made of cells • Cells are the smallest unit of life • Cells come from other living cells

4. All Cells have 3 Things • DNA • Cytoplasm • Cell membrane

5. Two Main Types of Cells Prokaryotic Eukaryotic Has a “true nucleus” DNA is housed there Has membrane-bound organelles Single or multicellular Plants, animals, fungi, and protists • No nucleus • DNA floats in cytoplasm • No membrane-bound organelles • All single-celled • Bacteria and Archaea

7. Cytoplasm • Jelly-like substance containing organelles that cushions and protects the cell

8. Cytosol • The fluid portion of cytoplasm minus the organelles

9. Cell membrane • Double-layered membrane that surrounds cells • Controls what goes in and out of the cell

10. Organelles • Structures that perform specific jobs in the cell • Surrounded by membranes

11. Nucleus • Round organelle in the center of cell • Houses the DNA • Controls the activities of the cell • Surrounded by the nuclear envelope • Contains pores that allow certain materials in and out

12. Nucleolus • Found inside the nucleus • Makes ribosomes

13. Cytoskeleton • Made of protein fibers • Provide structure and allow for movement

14. Types of Cytoskeleton • Microtubules • Long hollow tubes • Shape, “tracks” for organelle movement, and make fibers for cell division • Intermediate filaments • Smaller and give cell strength • Microfilaments • Smallest allow cells to move and divide and contact as in muscle cells

16. Endoplasmic Reticulum • Network of folded membranes with spaces between • Extension of the nuclear envelope • Delivers proteins to the Golgi • Two types • Smooth- without ribosomes • makes lipids and detoxifies the cell • Rough- studded with ribosomes • modifies proteins

18. Ribosomes • A combination of RNA and protein (no membrane) • Site of protein synthesis • Proteins are made here • Found on rough ER and free floating in cytoplasm

19. Golgi Apparatus • Aka Golgi body or Golgi complex • Close network of membranes and vesicles pinch off of it • Processes, sorts, and delivers proteins • Like UPS

21. Vesicle • Small membrane-bound sacs that transport substances in the cell

22. Endomembrane System • Connection between ER, vesicles, Golgi, then cell membrane • Parts of the membranes of these organelles pinch off and fuse to other parts to allow for transport in the cell

23. Mitochondria • Make energy for the cell in the form of ATP • Where the process of cellular respiration occurs • Known as the “powerhouse” of the cell

24. Mitochondria • Bean-shaped with folded inner membrane called cristae • Also have their own ribosomes and DNA inside • Cells like muscle cells will have more of these because they need more energy

26. Vacuole • Fluid-filled sac used for storing materials • Plant cells • Central vacuole for water storage

27. Lysosomes • Contain enzymes used for digestion • Enzymes are activated in the Golgi • Break down and recycle old cell parts • Defends the body from bacteria and viruses • http://www.cleanvideosearch.com/media/action/yt/watch?videoId=ekdIEpSf-1I

28. Centrioles • Cylinder-shaped • Microtubules arranged in a circle • Involved in cell division • Only found in animal cells

29. Cilia- in some cells • Small hairlike projections • Allow for movement • Not found in all cells • Found in paramecium and in respiratory tract

30. Flagella- in some cells • Tail-like projections • Allow for movement • Found in sperm

31. Flagellum

33. Cell Wall • Found in • Plants- made of cellulose • Fungi- made of chitin • Bacteria- made of peptidoglycan • Found outside the cell membrane • Thick and inflexible (rigid) • Provides protection and shape to the cell

34. Chloroplast • Only found in plant cells • Where photosynthesis occurs • Have sacs called thylakoid membranes containing chlorophyll • Own ribosomes and DNA

36. Cell Membrane By: Amber Tharpe

37. Cell Membrane AKA Plasma membrane

38. Cell membrane 2 layers of phospholipids Outer flexible boundary of cell Controls what goes in and out of the cell Selectively permeable Allows some things to cross, while not allowing others

39. Phospholipids 2 main parts Head Phosphate and Glycerol Polar (slightly charged) Hydrophilic- loves water Tail 2 fatty acid chains Nonpolar (not charged) Hydrophobic- hates water

40. Additional Parts of Cell Membrane • Cholesterol- strengthens the membrane • Proteins- give support and extend through one or more of the phospholipid layers to help materials cross • Carbohydrates- serve as ID tags to enable cells to distinguish between different types of cells

41. Transport through cell membrane • Depends on molecule’s: • Size • Polarity • Concentration in vs. out of the cell • Generally • Small, nonpolar molecules pass easily • Small polar transport through proteins • Large molecules are moved in vesicles

42. Receptor Protein that detects a signal molecule (ligand) and performs an action in response The ligand bonding causes a change in the 3-D shape of the receptor allowing it to do its job http://www.cleanvideosearch.com/media/action/yt/watch?v=LwI0fz18LK0 http://www.cleanvideosearch.com/media/action/yt/watch?v=Du-BwT0Ul2M

43. Receptor Protein

44. Passive Transport By: Amber Tharpe

45. Passive Transport • Movement of molecules across a membrane, without using energy • Usually small molecules • Types • Diffusion • Osmosis • Facilitated diffusion

46. Concentration • Amount of dissolved particles (solutes) in a solution • Concentration gradient • Difference in concentration from 1 area to the next

47. Diffusion • Movement of molecules from an area of high to low concentration • Moves down the concentration gradient • From high to low concentration

49. Equilibrium • No net reaction • Reaction occurs at the same rate forwards and backwards

50. Equilibrium = homeostasis before exists when the concentration of a substance is equal through out a space Molecules continue to move · · · · · · · · after · · · · · · · ·