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Cells

Cells. Leeuwenhoek. made a simple microscope (mid 1600’s ) magnified 270X Early microscope lenses made images larger but the image was not clear. Leeuwenhoek's Microscope. A) a screw for adjusting the height of the object being examined B) a metal plate serving as the body

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Cells

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  1. Cells

  2. Leeuwenhoek • made a simple microscope (mid 1600’s) • magnified 270X • Early microscope lenses made images larger but the image was not clear

  3. Leeuwenhoek's Microscope A) a screw for adjusting the height of the object being examined B) a metal plate serving as the body C) a skewer to impale the object and rotate it D) the lens itself, which was spherical

  4. CELL THEORY • A theory resulting from many scientists’ observations & conclusions

  5. CELL THEORY1. The basic unit of life is the cell. (Hooke) • In 1665, an English scientist named Robert Hooke made an improved microscope and viewed thin slices of cork viewing plant cell walls • Hooke named what he saw "cells"

  6. CELL THEORY2. All living things are made of 1 or more cells. • Matthias Schleiden(botanist studying plants) • Theodore Schwann(zoologist studying animals) stated that all living things were made of cells Schwann Schleiden

  7. CELL THEORY3. All cells divide & come from oldcells. (Virchow) Virchow

  8. MODERN MICROSCOPES • A microscope is simple or compound depending on how many lenses it contains • A lens makes an enlarged image & directs light towards you eye

  9. A simple microscope has one lens • Similar to a magnifying glass • Magnificationis the change in apparent size produced by a microscope

  10. COMPOUND MICROSCOPE • A compound microscope has multiple lenses • (eyepiece & objective lenses)

  11. STEREOMICROSCOPE • creates a 3D image

  12. TOTAL MAGNIFICATION • Powers of theeyepiece (10X) multiplied by objective lenses determine total magnification.

  13. ELECTRON MICROSCOPES • More powerful; some can magnify up to 1,000,000X • Use a magnetic field in a vacuum to bend beams of electrons • Images must be photographed or produced electronically

  14. ScanningElectron Microscope (SEM) Electron microscope image of a spider Electron microscope image of a fly foot • produces realistic 3D image • only the surface of specimen can be observed

  15. TransmissionElectron Microscope (TEM) • produces 2D image of thinly sliced specimen • detailed cell parts (only inside a cell) can be observed

  16. ScanningTunneling Microscope (STM) • able to show arrangement of atoms

  17. Cell Structure & Function http://koning.ecsu.ctstateu.edu/cell/cell.html

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

  19. Examples of Cells Amoeba proteus Plant Stem Bacteria Red Blood Cell Nerve Cell

  20. Two Types of Cells Prokaryotic Eukaryotic

  21. Prokaryotic • Do not have structures surrounded by membranes • Few internal structures • One-celled organisms, Bacteria http://library.thinkquest.org/C004535/prokaryotic_cells.html

  22. Eukaryotic • Contain organelles surrounded by membranes • Most living organisms Plant Animal http://library.thinkquest.org/C004535/eukaryotic_cells.html

  23. “Typical” Animal Cell http://web.jjay.cuny.edu/~acarpi/NSC/images/cell.gif

  24. “Typical” Plant Cell http://waynesword.palomar.edu/images/plant3.gif

  25. Cell Parts Organelles

  26. Surrounding the Cell

  27. Cell Membrane • Outer membrane of cell that controls movement in and out of the cell • Double layer http://library.thinkquest.org/12413/structures.html

  28. Cell Wall • Most commonly found in plant cells & bacteria • Supports & protects cells http://library.thinkquest.org/12413/structures.html

  29. Inside the Cell

  30. Nucleus • Directs cell activities • Separated from cytoplasm by nuclear membrane • Contains genetic material - DNA

  31. Nuclear Membrane • Surrounds nucleus • Made of two layers • Openings allow material to enter and leave nucleus http://library.thinkquest.org/12413/structures.html

  32. Chromosomes • In nucleus • Made of DNA • Contain instructions for traits & characteristics http://library.thinkquest.org/12413/structures.html

  33. Nucleolus • Inside nucleus • Contains RNA to build proteins http://library.thinkquest.org/12413/structures.html

  34. Cytoplasm • Gel-like mixture • Surrounded by cell membrane • Contains hereditary material

  35. Endoplasmic Reticulum • Moves materials around in cell • Smooth type: lacks ribosomes • Rough type (pictured): ribosomes embedded in surface http://library.thinkquest.org/12413/structures.html

  36. Ribosomes • Each cell contains thousands • Make proteins • Found on ER & floating throughout the cell http://library.thinkquest.org/12413/structures.html

  37. Mitochondria • Produces energy through chemical reactions – breaking down fats & carbohydrates • Controls level of water and other materials in cell • Recycles and decomposes proteins, fats, and carbohydrates http://library.thinkquest.org/12413/structures.html

  38. Golgi Bodies • Protein 'packaging plant' • Move materials within the cell • Move materials out of the cell http://library.thinkquest.org/12413/structures.html

  39. Lysosome • Digestive 'plant' for proteins, fats, and carbohydrates • Transports undigested material to cell membrane for removal • Cell breaks down if lysosome explodes http://library.thinkquest.org/12413/structures.html

  40. Vacuoles • Membrane-bound sacs for storage, digestion, and waste removal • Contains water solution • Help plants maintain shape http://library.thinkquest.org/12413/structures.html

  41. Chloroplast • Usually found in plant cells • Contains green chlorophyll • Where photosynthesis takes place http://library.thinkquest.org/12413/structures.html

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