Presentation on theme: "Learning Objectives: a.Chemistry is the study of matter, the physical substance of all materials. b.There is a difference between physical and biological."— Presentation transcript:
Learning Objectives: a.Chemistry is the study of matter, the physical substance of all materials. b.There is a difference between physical and biological sciences that arises from natural science. c.DNA and the purpose of the Human Genome Project - to explore, explore, explore
d.The development of refrigerants is rooted in chemistry. e.A brief intro about the ozone layer. f.Distinctions of scientific discovery among basic science, applied science, and technology. g.The use of fossil fuels used in everyday life and global warming. h.Benefit and risk analysis factors.
2.Chemistry is the study of matter and the changes it can undergo. 3.Chemistry is a physical science Living in a World of Chemistry a.What does Chemistry Mean to You? 1.Maybe chemistry means ??? to you.
The amazing effect of nitric acid (b) on copper (a). A young man, Ira Remsen (1864-1927) dropped a copper penny into nitric acid to see what would happen. This is chemistry at work! What type of chemistry do you know that we use in our daily lives?
Living in a World of Chemistry b.Natural Sciences have been associated with observation of nature. 1.Our physical and biological environment. The Natural Science Requires Mathematics Physical Sciences Study of matter and energy Biological Sciences Study of living organisms Biochemistry Chemistry
Physical Sciences Study of matter and energy GeologyAstronomy Physics Chemistry Chemical Physics Cosmo Chemistry Geo Chemistry Analytical Physical Organic Inorganic Determination of structure & composition Basic physical processes of chemistry Carbon compounds Non-Carbon compounds
Biological Sciences Study of living organisms Botany Zoology MicrobiologyCell BiologyGeneticsEcologyPhysiology Microscopic organism Cell structure and Function HeredityEnvironmentFunction
Living in a World of Chemistry c.DNA and The Human Genome Project. 1.DNA is an abbreviation for Deoxyribonucleic acid and is present throughout our bodies. 2.DNA provides the fingerprint for an individual. 3.The study of DNA is one aspect of biochemistry.
An abstract picture of how DNA unravels and is reproduced. In this way, a parent's DNA is passed to the offspring. More to be discussed in Ch 15.
Living in a World of Chemistry c.DNA and The Human Genome Project 1.In 2000, a revolution in our knowledge of DNA begins. 2.A non-profit consortium called The Human Genome Project begins. 3.The map of human DNA is completed in April 2003 where the location of every segment of human DNA is identified.
The original publication by the leaders of The Human Genome project make the following prophetic statement: Purpose of The Human Genome Project “It has not escaped our notice that the more we learn about the human genome, the more there is to explore.” Development of products that improve the health of humans, other animals, and plants Understanding of hereditary diseases Development of drugs to cure hereditary diseases Alternation of an individual’s genetic makeup to prevent or cure a disease The study of why a drug can be effective in some individuals but not in others Exact matching of drugs to an individual’s genetics makeup Development of improved agricultural crops and animals Creation of genetically modified bacteria that will mass-produce desirable chemical products Use of genetic information for a better understanding of evolution Among these ongoing explorations are the following:
Living in a World of Chemistry d.Air-Conditioning/Refrigerants. 1.Refrigerants have been in use since the late 1800s. 2.This process requires a fluid that absorbs heat as it evaporates, releases heat when it condenses, and can be continuously cycled through evaporation and condensation without breaking down. 3.The development of chlorofluorocarbons, often referred to as CFCs, less hazardous refrigerants after WWII.
Thomas Midgley Jr. invented Chlorofluorocarbons (CFCs) Credit: Kettering University
Living in a World of Chemistry d.Air-Conditioning/Refrigerants 4.The Problem with CFC’s did not emerge until 1970: damage to the environment. 5.By the 1980’s, it became clear that CFC’s reacted with the stratosphere, where they interact with the ozone layer, and destroy it. e.The Ozone Layer (Depletion) 1.Ozone in the stratosphere absorbs ultraviolet radiation, it is like the Earth’s sunscreen. 2.Increased ultraviolet exposure is harmful to the environment and to us.
Ozone hole over Antarctica, October 2005 Will learn more about ozone depletion later in the semester.
Living in a World of Chemistry f.Distinguishing between basic science, applied science, and technology. 1.Basic science, or basic research, is the pursuit of knowledge about the universe with no short-term practical objectives for application in mind. Ex. Biochemists who struggled for years to understand exactly how DNA functions within cells were doing basic science. 2.Applied science has the well-defined, short-term goal of solving a specific problem. Ex. The search for a better refrigerant by Midgley and his colleagues.
Living in a World of Chemistry f.Distinguishing between basic science, applied science, and technology cont. 3.Technology, also an application of scientific knowledge, is a bit more difficult to define. In essence, it is the sum of the way we apply science in the context of our society, our economic system, and our industry. Ex. The first refrigerators and automobile air conditioners designed to use CFCs were the products of a new technology. Ways to manipulate DNA to make new medicines or other marketable products is referred to as biotechnology.
Living in a World of Chemistry g.Fossil Fuels and a Brief intro to Global Warming. 1.Fossil fuels are coal, oil, and natural gas used to support consumer-driven societies and their associated lifestyles. 2.The fuels are burned in a variety of vehicles. 3.Other uses of fossil fuel include powering an engine, providing heat and cooling our homes. 4.Fossil fuels are nonrenewable energy resources, eventually our supply will run out!
Living in a World of Chemistry g.Fossil Fuels and a Brief intro to Global Warming 5.Depletion of traditional sources of energy such as petroleum has led to the development of alternative sources of energy. 6.Renewable energy sources can be replenished on a short time scale; e.g., solar power, wind, and biomass. 7.Water vapor and carbon dioxide (CO 2 ) are gases that are known to absorb and trap heat radiation (Ex. in nuclear reactors).
Municipal solid waste recycling rates, 1960-2003 Source: EPA RECYCLE!!!
Living in a World of Chemistry g.Fossil Fuels and a Brief intro to Global Warming 8.Global warming or the greenhouse effect is a warming of the Earth by a layer of gases that trap the sun’s energy. 9.Human activity appears to be causing an increase in the amount of atmospheric CO 2. 10.Increased atmospheric CO 2 appears to be enhancing the greenhouse effect, leading to an increase in average global temperatures.
The Earth's atmosphere acts like the glass of a greenhouse
CO 2 levels are still increasing in the atmosphere Source: National Oceanic and Atmospheric Administration (NOAA).
Living in a World of Chemistry h.Benefits/Risks Tradeoff 8.It is important to consider how society weighs the benefit of some activities, the use of some chemicals, or the use of some new technologies against the potential risks. Ex. Automobiles offer efficient transportation, yet automobiles are responsible for thousands of deaths and considerable pollution each year. We accept these risks while, at the same time, making efforts to minimize or eliminate them. 9.What is the risk-benefit tradeoff for vaccination? 10.With any benefit vs. risk analysis, several factors come onto play.
An excellent discussion of these factors is presented in the June 2003 Harvard Center for Risk Analysis (HCRA). The authors identify the following major risk perception factors: Level of dread: Which do you dread more, for example, a heart attack or cancer? Control: We feel safer when we are in control. Natural or human-made risk: Natural risks seem less worrisome. Choice: Do you have a choice in the risk? Involvement of children: Risks that may be acceptable for adults may not be seen in the same light when children are involved. Newness of risk: Newly perceived risks seem worse than “old” risks. Awareness: Simply becoming more aware of a risk makes it seem more serious than it may really be. The popular press may contribute to this problem in its effort to keep us well-informed.
Can it happen to you? Not long ago American citizens didn’t worry much about terrorism because “it doesn’t happen here.” September 11, 2001, certainly changed that. Trust: We tend to be more willing to accept risks imposed on us by those we trust than by those we do not. Risk-benefit tradeoff: Benefits tend to make risks more acceptable. Living in a World of Chemistry h.Benefits/Risks Tradeoff cont.
Consider the following risk comparison of “natural” versus “human-made” risks. Many are opposed to the use of “toxic chemicals” around food products, yet toxicologists estimate that the typical American diet contains ten thousand times more naturally occurring cancer-causing chemicals than those of the synthetic variety. Over time our ability to detect the presence of toxic substances (concentration) has changed from levels in the parts per hundred (%) to levels below parts per million (ppm), parts per billion (ppb), and now parts per trillion (ppt).