330 likes | 357 Views
MAIN IDEA Cells are the basic “building blocks” of all living things. The cell theory grew out of the work of many scientists and improvements in the microscope.
E N D
MAIN IDEA Cells are the basic “building blocks” of all living things.
The cell theory grew out of the work of many scientists and improvements in the microscope. • Many scientists and nonscientists, over hundreds of years have contributed to our present day understanding of cell structure and function.
The invention of the microscope in the 1600’s provided the opportunity to make detailed observations of cell structures and activities.
Robert Hooke 1665 • Observed holes in cork under microsocope. • Coined the term “cells” • Empty spaces were actually where living cells were before dying – he just saw cell walls
Anton von Leeuwonhoek (just call me Tony) * Dutch lens maker * First to observe and describe single-celled microorganisms Ex. bacteria and protists * Called them animalcules and cavorting beasties
Robert Brown Robby Bobby said – “That dark structure found inside many cells should be named the Nucleus”
Theodore Schleiden Ted said - “All plants are made of cells”
Matthias Schwann Matt knew where it was at when he declared “ALL animals (like swans) are made of cells”
Rudolf Virchow Rejected the concept of spontaneous generation, which held that organisms could arise from nonliving matter spontaneously. Rudy’s Rule: “All cells are made by other cells”
Theory – An explanation for a wide body of evidence gathered over time through observation and experimentation. A theory ties lots of findings together and tries to provide a unifying explanation.
The cell theory grew out of the work of many scientists and improvements in the microscope. • Many scientists contributed to the cell theory. • More was learned about cells as microscopes improved. • The cell theory is a unifying concept of biology.
3 Principles of the Cell Theory 1. All organisms are made of cells.
3 Principles of the Cell Theory 1. All organisms are made of cells. 2. All cells are made by other living cells
3 Principles of the Cell Theory 1. All organisms are made of cells. 2. All cells are made by other living cells 3. Cells are the “building blocks” of all life .
There are thousands of different types of cells that make up living organisms.
Two categories of cells based on their internal structure. 1. Prokaryotic Cells DO NOT have a nucleus or organelles surrounded by membranes 2. Eukaryotic Cells DO have a nucleus and membrane surrounded organelles
nucleus cell membrane Two major cell types: Eukaryotic cells and Prokaryotic cells Eukaryotic cells have a nucleus.
nucleus organelles cell membrane Two major cell types: Eukaryotic cells and Prokaryotic cells • Eukaryotic cells have a nucleus. • Eukaryotic cells have membrane-bound organelles.
nucleus organelles cell membrane Two major cell types: Eukaryotic cells and Prokaryotic cells • Prokaryotic cells do not have a nucleus.
nucleus organelles cell membrane cytoplasm Two major cell types: Eukaryotic cells and Prokaryotic cells • Prokaryotic cells do not have a nucleus. • Prokaryotic cells do not have membrane-bound organelles.
Fossil Evidence of Prokaryotic and Eukaryotic Cells PROKARYOTES EUKARYOTES Evolved 1.5 billion yrs ago First ones were unicellular Later cells became multicellular Photosynthetic marine bacteria 3.5 Billion Years Ago
Organisms are made of either prokaryotic or eukaryotic cells • Prokaryotes are organisms made of Prokaryotic cells Only Bacteria are Prokaryotes • Eukaryotes are organisms made of Eukaryotic cells Organisms include: • Protists • Fungi • Plants • Animals
Bacterium (colored SEM; magnification 8800x) Cells come in many different shapes and carry out many different jobs. However they all share some features. All cells do share some characteristics • Most cells are microscopic.
cell membrane Bacterium (colored SEM; magnification 8800x) All cells share some characteristics • Most cells are microscopic • All cells are separated from their environment by a plasmamembrane
cell membrane cytoplasm Bacterium (colored SEM; magnification 8800x) All cells share some characteristics • Most cells are microscopic • All cells are enclosed by a plasma membrane • All cells are filled with gel like fluid called cytoplasm
cell membrane cytoplasm Bacterium (colored SEM; magnification 8800x) All cells share some characteristics • Most cells are microscopic • All cells are enclosed by a plasma membrane • All cells are filled with cytoplasm • All cells contain DNA
Endosymbiotic Theory • Developed in the 1970’s • Endosymbiosis- a relationship in which one organism lives within the body of another and both benefit from relationship. • Early mitochondria and chloroplasts were once simple prokaryotic cells that were taken up by larger prokaryotes around 1.5 bya. Some of the smaller prokaryotes may have survived inside the larger ones. Survival advantage-Both structures helped the larger cell get energy. Mitochondria and Chloroplasts have their own DNA & ribosomes, can copy themselves
Helpful Animations and Videos Prokaryotic vs. Eukaryotic Cells: Comparison and Contrast http://science.howstuffworks.com/life/28732-assignment-discovery-elements-of-cells-video.htm http://www.youtube.com/watch?v=y623clAREHI http://www.youtube.com/watch?v=yWy4o_UfZ4A http://www.youtube.com/watch?v=WRO-DPyB9Bk
Prokaryotic Cells Eukaryotic Cells Nucleus Membrane surrounded organelles Larger Single or Multicellular Found in protists, fungi,plant and animals Linear DNA Ribosomes (protein factories) No Nucleus No membrane surrounded organelles Smaller Single celled/ Unicellular Found in bacteria, archaea Circular DNA Ribosomes – not surrounded by a membrane