chapter 2 - A ugust 31, 2009 Hypothesis- data and...


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August 31, 2009 Hypothesis- data and observation then make an educated guess Theory- strength of data and room for adjustments Law- proving over and over again. Little wiggle room but possible to negotiate the fine points *scientists will agree if data is agreeable. Pirates and temperature? Chapter 2: the Chemistry of Life Biology- study of life means: comprised of cells, acquire and use energy, contain genetic information, control internal environments- cytotoxic t cells punch holes in cells so can’t do this and other cells die Unifying concept of bio- cell theory, molecular basis of inheritance, evolutionary conservation, evolutionary change Rules/concepts- evolution- explains likes and differences between organisms; homeostasis- ability to maintain internal environment including pH, ions and water content; osmosis- if move solutes, then water will follow; conformation- shape relates to function, change shape, then you change form, function follows form. What are the chemical elements that make up living organisms? Section 2.1 A. Matter is composed of atoms- includes dense positively charged nucleus which negative electrons move around. Atom is neutral. Nucleus contains one or more proton and sometimes one or more neutron. Neutron is not necessary- ex: hydrogen** 1. Atomic mass unit- unit of mass for atoms. Electrons (not physical things, theoretical concept) are not weighed into the weight of an atom bc its so small although they determine how atoms interact with others. Electrons have no weight, but do have charge B. Element- pure substance of only one type of atom. Most common- carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. 92 naturally occurring and 25 most wanted
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1. SPONCH- 2. S- sulfur- amino acid- build proteins 3. P- phosphorus- nucleotides- structures is …. ? builds ATP, DNA, RNA 4. O-oxygen- water and carbon dioxide 5. N- nitrogen- nucleotides and amino acids (amino group and acid group)- builds proteins 100-500 *MOST IMPORTANT* 6. C- carbon- carbohydrates- glucose for energy 7. H- hydrogen- hydrogen gas, pH, and ATP formation C. Protons- each element has a different number- atomic number. Mass number is total of protons and neutrons in the nucleus. Have weight and charge D. Neutrons- sometimes the number of neutrons is not constant in the nucleus. Have weight, no charge 1. Isotopes- same element but different amounts of neutrons. Many have multiple isotopes; hydrogen, deuterium, tritium. Most are called “carbon, carbon-12, carbon-13, carbon-14”. Atomic weight is average of the mass numbers of a representative sample of atoms of the element, with all isotopes in their normally occurring proportions.
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This note was uploaded on 01/26/2011 for the course BIO 0150 taught by Professor Roberts during the Fall '09 term at Pittsburgh.

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