Chapter 1- CELLS!

Chapter 1- CELLS!

Chapter 1- CELLS!

Section 1.1

  1. What are cells?
  2. Basic structural and functional unit of life.
  3. Come in all shapes and sizes.
  1. How did we discover cells?
  2. The microscope led to the discovery of cells.
  1. Who discovered cells?
  2. Scientist: Robert Hooke
  3. Observed dead cork cells.
  4. Said boxes looked like tiny rooms or cells, that is where they get their name.
  5. Used a microscope at 30x magnification
  6. Scientist: Anton van Leeuwenhoek
  7. 1st to observe living cells.
  8. Looked at pond water
  9. Used a microscope at 300x magnification
  1. Where do cells come from?
  2. Scientist: Fransisco Redi
  3. Experiment:
  4. Control group- flask with meat uncovered
  5. Experimental group- flask with meat with stopper on top
  6. Results- flask that did NOT have the stopper on top produced larva because flies laid their eggs on the meat. Flask with stopper contained no maggots.
  7. Scientist: Louis Pasteur
  8. Discovered- cells must come from other cells.
  9. Disproved theory of “spontaneous generation”
  10. Spontaneous generation: theory that life can just appear out of nowhere.
  11. Experiment:
  12. Control group- flask that was not exposed to air
  13. Experimental group- flask exposed to air
  14. Results- flask that was exposed to the air contained bacteria in it from the air. Flask that wasn’t exposed did not contain anything.
  15. Pasteur came up with the idea of ______after discovering bacteria could contaminate milk from the air. This process kills the bacteria so that it does not harm us!
  1. Cell Theory
  2. Cells come only from other living cells.
  3. Every living thing is made of 1 or more cells.
  4. Cells carry out the functions needed to support life.

Chapter 1- CELLS!

Section 1.2-

  1. How small are cells?
  2. We use micrometers (μm )= 1 millionth of a meter!
  3. Range from 1 μm to 1000 μm
  1. Different Types of Microscopes
  2. Compound Light Microscope (LM)
  3. Uses light
  4. Thin specimen
  5. Total magnification = 40x-100x
  6. Used to see cells, but not organelles inside
  7. Scanning Electron Microscrope (SEM)
  8. Uses electrons that bounce off the specimen
  9. 3-D image, must be dead 
  10. Specimen is coated in metal
  11. Total magnification= 100,000x
  12. See details of OUTSIDE of cell, cell membrane and cilia.
  13. Transmission Electron Miscroscope (TEM)
  14. Uses electrons to deflect through specimen
  15. Thin specimen
  16. Total magnification= 300,000x
  17. Allows us to see organelles INSIDE cell.
  1. Prokaryote vs. Eukaryote??
  2. Prokaryotes:
  3. Have circular DNA
  4. NO nucleus
  5. Doesn’t have membrane-bound organelles
  6. Most unicellular organisms are prokaryotes
  7. Example: Bacteria
  8. Eukaryotes:
  9. Have linear DNA that is in a double helix shape.
  10. Has a nucleus.
  11. Have membrane-bound organelles.
  12. Mostly multicellular although there are some unicellular eukaryotes (ex:Yeast)
  13. Endosymbiont theory
  14. Scientist:Lynn Margulis
  15. Theory- eukaryotes came from prokaryotes, Cell “engulfed” other cells.
  16. Evidence of theory-
  17. Mitochondria have circular DNA like bacteria
  18. Replicates (reproduces) like bacteria separate from the host cell
  19. Mitochondria make their own proteins
  20. Mitochondria have two membranes (one from the host cell and one from their own cell membrane)
Top View