Download CHAPTER 7.1 OUTLINE SHEET A. Development of Cell Theory 1

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 Pre­existing 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 Pre­existing 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 Pre­existing 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: 2­5x
2. Stereomicroscope: "Dissecting Scope"
Uses only 2 lens: Ocular and Objective
Magnifying Power: 5­30x
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 10,000­100,000X
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 X­Ray
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 Ribosomes­build 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 Ribosomes­build proteins
Flagella­ motion
Mitochondria­ produce energy
Vacuole­ storage
Lysosome­Digestion
Chloroplast­ Photosynthesis
Advanced Specific Functions
Eukaryotic Plant Cell
13
14
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
21
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
24
2. Size
Plant Cells are usually Larger than Animal cells
Typical Plant Cell­ 10­100 um
Typical Animal Cell 10­30 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
26
Typical Animal Cell
Typical Plant Cell
27
28