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Lecture 2: What is life?. ...Are we Alive?. Now playing: Soft Cell “Tainted Love”. Lecture 2 : Goals-. 1. Definitions of life & death. 2. Understand concepts of life, death, organization, structure, function and metabolism.
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Lecture 2: What is life? ...Are we Alive?... Now playing: Soft Cell “Tainted Love”
Lecture 2 : Goals- 1. Definitions of life & death 2. Understand concepts of life, death, organization, structure, function and metabolism 3. Relate topics to methods of scientific inquiry, personal experience and knowing Assignment: 1. Read: Start Reading Assignment for lecture 3 2. Websites: http://www.mhhe.com/biosci/genbio/maderinquiry/crit3.html http://www.purefood.org/meatlink.htmlhttp://www.mad-cow.org/ http://www.purefood.org/meatlink.html http://gened.emc.maricopa.edu/bio/bio181/BIOBK/BioBookGlyc.html http://www.mhhe.com/biosci/genbio/maderinquiry /crit6.html http://www.mhhe.com/biosci/genbio/maderinquiry/crit3.html
Where does life come from? At least 3 theories: • Divine Creation • Cosmic Inoculation: • Pamspermia • Neo-Darwinian Evolution or “Macroevolution”
It’s Difficult to Understand Life and Death • No first hand, personal experience or information • No cognitive experience: can’t remember • pre- or non-existence… • No cognitive remembrance of or as • life started…
Characteristics of Death • Absence of life • Total and permanent cessation • of all vital (living) function • Absence of the characteristics of life
Definition of Life • The quality that distinguishes a vital and functional organism from inanimate objects. • An embodied organismic state characterized by the capacity for metabolism, growth, reaction to stimuli and reproduction. • A principle or force that underlies the distinctive quality of animate • beings.
Conditions for Life on Earth:The Anthropic Principle • 1st Cause or Primary Mover • 2nd Cause or Big Bang • 3rd Cause or Physics • 4th Cause or Chemistry • 5th Cause or Biology • 6th Cause or Ecology • 7th Cause or Environment
Physical, Chemical and Biological Properties of Life • Dynamic = changing • Elements • Molecules • Compounds • Macromolecules • Enzymes • Electrical phenomena • Optical activity of enzymes
Properties of LifeContinued: • Composed of building blocks = cells • Exhibit organization = tissue, organs • Metabolism • Growth • Irritability • Adaptability • Uniformity of class • Reproduction
Irritability An immediate response to stimulus = nervous system Adaptation An inherited characteristic that enables an organism to survive Reproduction Passing on the biochemical instructions (genes) to the next generation Life’s Characteristics
Life’s Organization Atoms Amino Acids Macromolecules Organelles Cells Tissues Organs Organ Systems Symbiotic organisms Individuals Populations Munn Field Riot 1998
Metabolism • Animal model • Plant model
Animal Metabolism Change Self Perpetuation Reproduction Metabolism Synthesis Offspring Energy Energy Nutrient Cycles Detritus Cycles Raw Materials H2O Cycle Growth and Development Steady State Respiration
Sunlight Carbohydrate Energy rich O2 Chloroplast Mitochondrion Energy poor CO2 + H2O Fusion ATP Biosynthesis Active transport Movement Bioluminescence Electricity 4H 1 He + e E = MC2 Plant Metabolism Photosynthesis Cellular respiration
What is the simplest form of life? • Phytoplasma and Mycoplasma = simplest cell, lack a cell wall, DNA for 200 functions (walking pneumonia, STD’s) Pneumonia mycoplasma • Virus = RNA or DNA wrapped in protein coat • (e.g. HIV, poliomyellitis) HIV
More simple life • Viroid = Tightly wound DNA or RNA (coconut cadang cadang, bunchy top) Cadang cadang • Prions = 1/100 to 1/1000 the size of a virus, composed of proteins (Scapies, Multiple Sclerosis, Lou Gehrig’s disease) scapies
Mad Cow Disease Bovine Spongiform Encephalopathy: Prions in action Transmission via contaminated sheep proteins fed to cattle in Great Britain
Science is all about description. How Biologists Measure Size: Metrics Assignment: Learn the metric measuring system and life sizes
Lecture 2: What is life? Summary Origins Definitions Properties Characteristics Organization Energy Communication Simple forms of life How living organisms are described: e.g. measured, photographed, weighed, dissected, chemically analyzed, etc. Now playing: Soft Cell “Tainted Love”
Life is what happens when you’re busy making other plans. --John Lennon (1940-1980) British singer/songwriter