Week 1 Notes
Week 1 Notes BISC 207025
Popular in Introductory Biology I
Popular in Nursing and Health Sciences
This 4 page Class Notes was uploaded by Lauren Buch on Sunday September 20, 2015. The Class Notes belongs to BISC 207025 at University of Delaware taught by Dr. Oyenike Olabisi in Spring 2015. Since its upload, it has received 51 views. For similar materials see Introductory Biology I in Nursing and Health Sciences at University of Delaware.
Reviews for Week 1 Notes
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 09/20/15
Introduction to Biology Dr Olabisi Week 1 11 The Scienti c Method A For most scientists studies of the natural world involve the complementary processes of observation and experimentation a Observation the act of viewing the world around us b Experimentation disciplined and controlled way of asking and answering questions in an unbiased manner B Hypothesis tentative explanations brought about by observation a Makes predictions that can be tested by observation and experiments b Testable because they have an explanation from previous observation and predict the results of future observation C If results are consistent a theory can be made a Theory a general explanation of the world supported by a large body of experiments and observations D Evolution single most important theory in biology E Shows that all living organisms come from other living organisms a Pasteur and Redi s bacteria experiments b Organisms are not generated spontaneously from chemical components 12 Chemical and Physical Properties A Key characteristics of living organisms a Complexity with precise spatial organization on several scales b The ability to change in response to the environment c The ability to reproduce d The capacity to evolve B Living a nonliving organisms are both subject to the basic laws of chemistry and physics a All the elements that make up living organisms are in nonliving environments C Laws of thermodynamics a Energy can neither be created nor destroyed i Can only be transferred from one form to another ii All organisms obtain energy from the sun or from chemical compounds b The degree of disorder in the universe tends to increase i Entropy disorder in the system ii Living systems are highly organized but the cells exists in an environment iii As energy is harnessed by cells only some is used to do work the rest is dissipated by heat 1 Conversions of energy from one form to another are never completely efficient 13 The Cell A Simplest selfreplicating entity that can exist as an independent unit of life P U 0 Every known living organism is either a single cell or a combination of them All have a discrete boundary that separates the interior of the cell from its eternal environment All have the ability to harness materials and energy from the environment E Nucleic acids a b an Store and transmit information needed for growth function and reproduction Essential feature of a cell ability to store and transmit information Essential feature of a cell to reproduce DNA deoxyribonucleic acid double stranded helix responsible that directs the formation of proteins i Four different kinds of molecules create sequences that determine function ii Easily replicated 1 Has to be precise and accurate 2 Uses one strand of the helix to make a new one 3 Mistakes introduced can be lethal to the cell mutation a Can be caused during replication or environmental factors iii Proteins copy DNA info to RNA transcription iv RNA is read to determine how to build the protein translation v Central dogma of molecular biology pathway from DNA to RNA to protein vi Gene the DNA sequence that corresponds to a speci c protein product F Membranes a b 0 De ne cells and spaces within cells Essential feature of a cell plasma membrane that separates the living material within the cell from the nonliving environment inside is cytoplasm Active and dynamic interplay between cell and environment Also internal membranes to divide the cell into compartments i Nucleus houses cell DNA 1 Prokaryotes no nucleus a First cells b Found wherever life can persist c Small size reproduce rapidly obtain nutrients from diverse sources Most are singlecelled Many live in the gut and aid digestion Some cause disease salmonella TB Bacteria Archaea singlecell organisms that live in seemingly hostile conditions 2 Eukaryotes nucleus a Evolved 2 billion years ago much later b Animals plants fungi protists c Single cells yeast or multicellular PEG9 G Viruses a Agent that infects cells b Smaller and simpler than cells c Stable archive of genetic information RNA or DNA surrounded by a protein coat and sometimes a lipid envelope d Cannot harness energy from the environment e lnfects a cell by binding to its surface inserting its genetic material into the cell and uses the cellular machinery to replicate its own genetic material synthesize proteins and produce more viruses f Model system for problems in biology such as how genes turn on and off and how breast cancer develops 21 Properties of Atoms A Atom the basic unit of matter B Consist of protons neutrons and electrons a Protons positive charge b Neutrons no charge neutral c Electrons negative charge i Outside of nucleus in cloud orbitalshell d Atomic mass protons neutrons e Isotopes atoms of the same element that have different numbers of neutrons f lons electrically charged atoms lost or gained electrons g Elements arranged into the periodic table i Dmitri Mendeleev ii Arranged in order of increasing atomic number 22 Molecules and Chemical Bonds A Molecules substances made up of two or more atoms B Chemical bond form of attraction between atoms that holds them together C Covalent atoms share electrons a Combine to ll electron shell 8 octet rule b Polar unequal sharing of electrons i Water ii Electronegativity difference in the ability of an atom to attract electron iii Tends to increase across a row electrons are held more tightly to the nucleus c Hydrogen bond results when a hydrogen atom covalently bound to an electronegative atom of another molecule D lonic forms between oppositely charged ions a Positive ion and negative ion b Sodium chloride E Chemical reaction breaking and forming of chemical bonds a Atoms keep their identity only change bonds
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'