Chapter 1 Exploring Life and Science Characteristics shared by living organisms They are organized from the atom to the biosphere They use materials and energy from the environment They maintain a relatively constant internal environment homeostasis They respond to internal and external stimuli They reproduce and grow Have an evolutionary history through which organisms change over time What distinguishes humans from other living organisms Cultural heritage or patterns of our behavior passed from one generation to the next social community Highly developed brains helps us respond to change in the environment and different type of social Completely upright stance presence of the spinal cord backbone Creative language skills no other organisms have Varied tool use for perpetuation of the species to protect themselves survival example fire weapons processes tools Modification of our environment for our own purpose which may affect the biosphere some of those help and others destroy How do we classify humans Domain Kingdom Phylum Class Order Family Genus Species House cat Eukarya Animalia Both are animals Chordata Spinal cord Mammalia Human Eukarya Animalia Chordata Mammalia Primates upright stance doesn t eat their own kind Felidae Hominidae Felis Homo domesticus sapiens What do we know about science production of mammary glands in females body covered of hair Carnivora Science is a way of knowing about the natural world The process in which we come to know our environment and our biological system functions structures and remedies Science and scientists should be objective no emotions cannot be subjective for the betterment of life Scientific conclusions may change or be modified as our understanding and technology increase facilitates networking and communication Science is studied using the scientific method The Scientific Method Observations New observations are made and previous data are studied and compared Hypothesis Input from various sources is used to formulate a testable statement statement of a possibility Experiment Observations The hypothesis is tested by experiment or further observations Conclusions The results are analyzed and the hypothesis is supported or rejected If rejected rewrite the hypothesis If supported it becomes a scientific theory Scientific Theory Many experiments and observations support a theory A controlled study Variables Experimental variable is the variable that is purposely changed or manipulated test All other variables need to remain constant Groups Control group is a group for comparison that is not exposed to the experimental variable Test group is a group of subjects that are exposed to the experimental variable How the cause of ulcers was discovered The scientific method in action Observations Many patients had a particular bacterium near their ulcers Hypothesis Helicobacter pylori is the cause of gastritis and ulcers Experiment observations 1 H pylori was isolated and grown from ulcer patients st nd 2 Humans swallowing a H pylori solution developed inflammation in their stomachs Conclusion H pylori was the cause of most ulcers and can be cured by antibiotics Does science have social responsibilities Science is a way of acquiring knowledge about the natural world through a systematic process separating it from ethics religion and aesthetics Technology is the application of scientific knowledge to human interests o Biotechnology genetically modified bacteria and genetically modified crops o Gene technology cloning of humans or gene therapy to modify inheritance o Use of stem cells from embryos embryonic stem cells they grow into tissue for that particular patients lost0 Everyone is responsible Vocabulary neutrons Science and technology should be used to improve our lives All citizens should assume responsibility Everyone needs to be involved in making value judgments about the proper use of technology Atoms smallest unit of all maters Made of positive protons negative electrons and uncharged Biosphere everything ATP energy currency of the cell Materials Energy Homeostasis to maintain a relatively constant internal environment Homeo uniform and stasis static Example body temperature if you have a fever a particular mechanisms will move into action to restore homeostasis once again Stimuli change in surroundings or environment stimulus Example if it s hot outside the body will release the heat in form of sweat Evolution the process in which organisms change over time allowed by nature Reproduction formation of a new generation the way a species is continued Polar molecules Hydrophilic molecules that are made when a negative pole and a positive pole attract Nonpolar molecules Hydrophobic molecules Ex Vegetable oil Chapter 2 Chemistry of life The first cell evolved in water Liquid water does not change temperature quickly Water is liquid at room temperature All living organisms are 70 90 water Water has a high heat of evaporation Molecules of water cling together Water is a solvent for polar molecules Hydrogen bonds occur between hydrogen in a covalent bond and Frozen water is less dense than liquid water lighter a negatively charged atom and they hold water molecules together These are relatively weak bonds Vocabulary Cell functional and structional unit of all life Unicellular one cell bacteria fungi Multicellular many cells humans animals plants Acids are substances that dissociate and release hydrogen ions H Bases are substances that take up hydrogen ions H or release hydroxide ions OH Ph Scale is a measure of hydrogen ion H concentration o Working scale is 0 14 with 7 being neutral o A pH below 7 is acidic and above 7 is basic How organic molecules are built and broken down Dehydration reaction the removal of water that allows subunits to link together into larger molecules Hydrolysis reaction the addition of water that breaks larger molecules into their subunits Organic molecules in all living organisms o Carbohydrates A measure of hydrogen ion H concentration Made of subunits called monosaccharides Made of C H and O in which the H and O atoms are in a 2 1 ratio Function as short and long term energy storage Found as simple and complex forms Simple carbohydrates o Monosaccharide 1 carbon ring as found in glucose o Disaccharide 2 carbon rings as found in maltose Complex carbohydrates o Polysaccharides are made of many carbon rings Glycogen is the storage form in animals Starch is the storage form in plants o Lipids Molecules that do not
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