The Building Blocks of Life Cells & Cell Organelles The Building Blocks of Life 2008-2009

Cell Theory Cells first described by ________________ – 1665 First LIVING cells described by _______________________ _________________________ – all plants made of cells ___________ – all animals made of cells _____________ – all cells come from pre-existing cells Principles of Cell Theory ________ are the basic units of life all living things are __________________ of cells cells come only from other _____________

animal cells plant cells bacteria cells Types of cells Prokaryote - ____ organelles ___________ - organelles animal cells plant cells

Cell size comparison most _________ eukaryotic cells __-___ microns Bacterial cell Animal cell most _________ __-___ microns eukaryotic cells ____-___ microns Animation micron = micrometer = 1/1,000,000 meter diameter of human hair = ~20 microns

Prokaryote/Eukaryote DNA comparison Prokaryotes ________ internal organization – ______ organelles Prokaryote DNA shaped as a closed _______ floating in cytoplasm Nucleoid region Eukaryote DNA in ___________ chromosomes enclosed in a ______________

Prokaryote/Eukaryote Cell Wall Comparison Prokaryotes all have __________________ Unique composition - __________________ Eukaryotes may or may not have cell walls Animal cells – ______ Plant cells – cell walls made of _____________ Fungal cells – cell walls made of __________

Observing Cells – How We Know What We Know… Light Microscopes Remember Hooke and Van Leeuwenhoek Magnification _______ of image Resolving power Observing Organelles Too small for _________ microscope Electron Microscope Scanning EM ____________ views Transmission EM Thin sections of specimen – ________ views

TEM vs SEM – both are images of cells from a rabbit trachea (windpipe) TEM vs SEM – both are images of cells from a rabbit trachea (windpipe). Cilia are visible.

Why are cells small? With size increase, __________ grows _________ than surface area. Small objects have ________ surface area:volume ratio Cell/Plasma membrane functions as selective barrier Enough oxygen, nutrients, wastes must pass in to service entire volume of the cell Only so much “stuff” can pass through at a time. Need a surface large enough to accommodate volume, thus cells have to be ________________.

Eukaryotic Cells and Complex Internal Membranes ____________ create __________ Partition cells into __________ Provide separate “little rooms” so that ______________________ processes can go on at the same time in the cell Internal membranes of cells participate directly in metabolism _______________ are often built directly into membranes Chemical reactions occur at such sites All membranes are similar, but different All made of _________________ But suited to specific_______________ due to embedded enzymes, etc.

Why study cells? _______  _________  _______  ______ bodies are made up of cells cells do all the work of life!

The Work of Life What jobs do cells have to do for an organism to live… “breathe” ______________: CO2 vs. O2 _______ take in & digest food make ___________ _____ __________________ proteins, carbohydrates, fats, nucleic acids remove ___________ ____________ internal conditions ____________ to external environment ________ more _______ growth, repair, reproduction & development ATP

Stay Tuned for an in depth Tour of the Eukaryotic Cell! 2008-2009