CHAPTER 7.1 OUTLINE SHEET A. Development of Cell Theory 1. Identifying Cells a. Anton van Leeuwenhoek b. Robert Hooke 2. Development of Cell Theory a. Schleiden, Schwann, and Virchow 1. Schleiden 2. Schwann 3. Virchow B. The Cell Theory 1. All Living Things are Made Of Cells 2. Cells are the Basic Unit Of Structure and Function in Living Things 3. All Cells Come From Pre existing Cells by Cell Division C. Types of Cells 1. Pro v. Eu a. Prokaryote Characteristics b. Eukaryote Characteristics c. Endosymbiont Hypothesis 2. Animal v Plant a. 3 Main Differences 1. Shape 2. Size 3. Organelles 1
Chapter 7 Cell Structure and Function Bacteria Animal Cell 2
Chapter 7, Section 1 Life is Cellular A. Development of the Cell Theory 1. Identifying Cells The basic unit of living things a. Credit for Invention of the first Microscope goes to Anton Van Leeuwenhoek Eyeglass maker who crafted a very powerful magnifying lens 3
Observed Pond water and other available liquids and saw Animalcules He looked into any fluid he could get his hands on! 4
b. Robert Hooke (1665) Used a Version of Leeuwenhoek's Microscope to observe a piece of Cork comes from Trees!!! Cork Thought it resembled the rooms of a monastary which were called. CELLS hence the name! 5
2. Development of the Cell Theory A. Schleiden, Schwann, and Virchow 1. Schleiden: All Plants are made of cells 2. Schwann: All Animals are made of cells Well then I guess all living things are made of cells!!!!! But where do they come from? Thin AIR? 3. Virchow: All cells come from Pre existing Cells by a process called Cell Division 6
B. Cell Theory Developed by Schleiden, Schwann, and Virchow 1. All Living Things are Made Of Cells 2. Cells are the Basic Unit Of Structure and Function in Living Things 3. All Cells Come From Pre existing Cells by Cell Division Every Plant I look at is made of cells That's Funny! Every Animal I look at is made of cells They must come from other cells. 7
Types of Microscopes: 1. Magnifying Glass Simple Microscope Uses only 1 lens Magnifying Power: 2 5x 2. Stereomicroscope: "Dissecting Scope" Uses only 2 lens: Ocular and Objective Magnifying Power: 5 30x 3. Compound Light Microscope: Phase contrast Microscope 8
4. Electron Microscopes: Use a beam of electrons to create a digital image of a specimen. A. Scanning Electron Microscope: Bounces beams of electrons of a specimen in order to produce a computer generated 3D images. Can only view external features Magnification of 10,000 100,000X b. Transmission Electron Microscope: (TEM) Passes beams of electrons through a specimen in order to produce a computer generated 3D images. Can view internal features: Microscopic X Ray Magnification of up to 500,000X 9
C. Types of Cells 1. Prokaryotes v Eukaryotes All cells can be identified as either Prokaryotes or Eukaryotes a. Prokaryotes "First Cell" They were the only type of cell around 4 Billion Years Ago They represent the first types of life!!!! Today: Bacteria 1. Prokaryotes are simple! They do not have a Nucleus Central region where DNA is stored Their DNA floats freely in the cell not very well protected 2. They do not have Membrane bound Organelles These Organelles perform functions Can only perform One function at a time Their Goal= Survival 10
No Nucleus DNA free Floats (Nucleoid) Only organelles Ribosomes build proteins Flagella motion Very Basic necessities for life 11
b. Eukaryotes: "True Cells" They are the predominant cell type today They represent all plants, animals, and microscopic organisms such as plankton and mold!!! 1. Eukaryotes are complex! They do have Membrane bound Organelles These Organelles perform functions that allow these cells to perform more than one function 2. They Have a Nucleus Central region where DNA is stored Their DNA is well protected by the Nuclear Membrane Their Goal= Survive and Advance/Evolve 12
Eukaryotic Animal Cell Nucleus DNA well protected from injury/mutation Many organelles Ribosomes build proteins Flagella motion Mitochondria produce energy Vacuole storage Lysosome Digestion Chloroplast Photosynthesis Advanced Specific Functions Eukaryotic Plant Cell 13
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Prokaryotes Staphylococcus aureus CLM SEM TEM 15
Escherichia coli: CLM SEM TEM 16
Eukaryotes Human White Blood Cell leukocyte CLM SEM TEM 17
Typical plant cell: Onion Cells CLM SEM TEM 18
c. Endosymbiont Hypothesis (Lynn Margulis) Theory that tries to explain how Eukaryotes evolved from Prokaryotes Endosymbiosis When two things use each other for mutual benefit All cells were originally Prokaryotes limited evolutionary opportunity One day a large prokaryote ingests a smaller prokaryote each one had a different mode of survival ex. Engulfing food v. making own food Instead of digesting smaller prokaryotes uses its specialized role to provide energy from the sunlight (becomes an organelle) Large cell no longer has to find food..it can focus on avoiding predators or finding a suitable habitat Provides evolutionary opportunity These become the first Eukaryotes single celled organisms such as paramecium and euglena 19
Evidence of this Hypothesis includes: Organelles such as the nucleus, mitochondria, chloroplast, etc have their own membranes Mitochondria and Chloroplast (both responsible for energy production) have their own distinct DNA different from that found in the nucleus 20
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2. Animal Cells v Plant Cells (Eukaryotes) All Eukaryotes can be classified as Either Animal Cells or Plant Cells!!! Typical Animal Cell Typical Plant Cell 22
a. 3 Main Differences 1. Shape Animal cells are Irregular in shape Round/Oval with a lot of folds Human Cheek Cells Red Blood Cells Plant Cells are usually rectangular or square Regularly Shaped Onion Cells Elodea cells 23
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2. Size Plant Cells are usually Larger than Animal cells Typical Plant Cell 10 100 um Typical Animal Cell 10 30 um Of Course this is not definite 3. Organelles are Different a. Plants have a cell wall for additional protection b. Plants have Chloroplast Photosynthesis to make their own food d. Plants have larger Vacuoles for storage of water e. Animals have Centrioles reproduction 25
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Typical Animal Cell Typical Plant Cell 27
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