Textbook Chapter 1 - Introduction: Exploring Life Summer Assn

Website GNS AP Biology Chapter 1 - Introduction: Exploring Life

NEW AIM: What is Science? What is Science Science is something that you do. It is a verb. It’s the process we use to try and know something. Remember…its all about making observations and using them to build models, which are in turn used to make predicts/decisions. Chapter 1 - Introduction: Exploring Life

AIM: What is Science? How do we do science ? Chapter 1 - Introduction: Exploring Life

AIM: What is Science? It’s all about making observations... Chapter 1 - Introduction: Exploring Life Ex. The structure of DNA

AIM: What is Science? The observations: Chapter 1 - Introduction: Exploring Life Phoebus Levene Russian Organic Chemist Rockefeller University 1928 One of the first models of DNA (the tetranucleotide)

AIM: What is Science? The observations: Chapter 1 - Introduction: Exploring Life Phoebus Levene Russian Organic Chemist Rockefeller University 1928 One of the first models of DNA (the tetranucleotide) Levene observed the behavior of polarized light passing through molecular structures in order to determine the four nucleotides of DNA and how they covalently bind to each other.

AIM: What is Science? The observations: Chapter 1 - Introduction: Exploring Life Erwin Chargaff Austrian Biochemist Columbia University 1952

AIM: What is Science? The observations: Chapter 1 - Introduction: Exploring Life Erwin Chargaff Austrian Biochemist Columbia University 1952

AIM: What is Science? The observations: Chapter 1 - Introduction: Exploring Life Chargaff took DNA from many different species, hydrolyzed it down to nucleotides, and performed chromatography to separate them from each other and compare concentrations. He observed an A:T ratio of 1:1 and a C:G ratio of 1:1, but the (A/T):(C/G) ratio varied, which refuted the tetranucleotide model. He did not observe or predict base pairing (That A hydrogen bonds to T, etc…)

AIM: What is Science? The observations: Chapter 1 - Introduction: Exploring Life Rosalind Franklin British Chemist/Physicist King’s College 1953

AIM: What is Science? The observations: Chapter 1 - Introduction: Exploring Life Dr. Franklin used X-rays as a means of making observations. She purified DNA is a very special way and then hit the DNA with Xrays to produce the image to the right (photo 51)

AIM: What is Science? The observations: Chapter 1 - Introduction: Exploring Life Photo 51 has a particular pattern that indicates the molecule is a double helix. Controversy ensued after James Watson got his eyes on the photo before being published, which can be read about here: salind-franklin #scientific- discoveries-and-credit-controversy salind-franklin #scientific- discoveries-and-credit-controversy

AIM: What is Science? The observations: Chapter 1 - Introduction: Exploring Life Rosalind Franklin British Chemist/Physicist King’s College 1953 Map showing England and the distance between Franklin and Watson (Cavendish Labs)

AIM: What is Science? The current DNA model: Chapter 1 - Introduction: Exploring Life James Watson (mol. biologist) Francis Crick (biophysicist) University of Cambridge 1953

AIM: What is Science? The current DNA model: Chapter 1 - Introduction: Exploring Life Watson and Crick using the following observation without ever doing a single experiment to build the current model of DNA: 1.Polarized light observations indicating the four nucleotides and how they are connected 2.Chargaffs chromatography observation that A:T is 1:1 and C:G is 1:1, but vary in ratio to each other. 3.The unpublished photo 51 indicating a double helix

AIM: What is Science? The current DNA model: Chapter 1 - Introduction: Exploring Life James Watson (mol. biologist) Francis Crick (biophysicist) University of Cambridge 1953 Where are the control groups in all this science?

AIM: What is Science? How were the foundations of genetics unraveled? Chapter 1 - Introduction: Exploring Life Through careful observations of pea plant matings!

AIM: What is Science? How were the foundations of genetics unraveled? Chapter 1 - Introduction: Exploring Life

AIM: What is Science? It is all about careful observation (data collection)… Chapter 1 - Introduction: Exploring Life Followed by building models that fit the data… SCIENCE:

AIM: What is Science? Chapter 1 - Introduction: Exploring Life SCIENCE: Have people figured out better ways to observe DNA? YES! There are a number of techniques, but none as amazing as X-ray crystallography to view the molecular world!!!

AIM: What is Science? Chapter 1 - Introduction: Exploring Life SCIENCE: Modern day diffraction image data (observation) off a crystallized molecule… Fancy math Data (Observation) of where electrons are located in crystal… Model of the molecule within the electron density data….

AIM: What is Science? The most sophisticated scientific instrument? Chapter 1 - Introduction: Exploring Life SCIENCE:

AIM: What is Science? All you do is collect and process data…build and refine models…and use these models to make predictions constantly… Chapter 1 - Introduction: Exploring Life SCIENCE:

AIM: What is Science? Come up with your own example of you doing science today… and write it up Chapter 1 - Introduction: Exploring Life SCIENCE:

AIM: What is Science? We are always doing science! Because you are always making observations, predictions, etc… When you walk down the hall you are collected data (visual data with your eyes, auditory data with your ears, etc…). With this data you generate questions and make predictions. For example, you observe someone running at you. Hypothesis: The person will run into me. Prediction: If I do not move then I will get hit. Experiment: Stay put. Results: The person hit me supporting my hypothesis. Chapter 1 - Introduction: Exploring Life

AIM: What is Science? We are always doing science. In fact, what you see, the image in front of you right now, is a scientific model. Explain. Chapter 1 - Introduction: Exploring Life SCIENCE:

AIM: What is Science? Chapter 1 - Introduction: Exploring Life How does the scientific enterprise actually work? What is the goal of this enterprise?

AIM: What is Science? What do scientists do with their findings? They publish them in scientific journals like Science, Nature, Cell, EMBO, PLOS One, etc… Chapter 1 - Introduction: Exploring Life

AIM: What is Science? Tentative and Fallible The findings of science are based on observation, but the observations could be misleading. For example, the Earth appears to be flat… Likewise, people thought Newton’s law of gravity was correct, but Einstein came along and revised it. This type of thing happens all the time. In addition, it was originally thought that water was HO. All of the observations pointed to HO at the time… The more reliable observations you make, the closer one gets to knowing the truth… Chapter 1 - Introduction: Exploring Life

AIM: What is Science? Theory 1. Very broad in nature (describe many, many different phenomenon). 2. Supported by enormous numbers of observations 3. Examples: Theory of Evolution Cell Theory Law 1. Very concise in nature (describes a very specific phenomenon). 2. Supported by enormous numbers of observations 3. Examples: Law of Gravity Laws of thermodynamics Laws of motion Chapter 1 - Introduction: Exploring Life

AIM: What is Science? GOD and Science Chapter 1 - Introduction: Exploring Life

AIM: What is Science? So is this class really about science ? Chapter 1 - Introduction: Exploring Life

AIM: What is Science? The hierarchy of life, emergent properties, and the structure -function relationship science ? Chapter 1 - Introduction: Exploring Life The Course Outline: Library / Book Analogy

AIM: How do organisms build/break macromolecules? Chapter 3 - The Molecules of Cells AIM: How is all life united? Chapter 1 - Introduction: The Scientific Study of LifeChapter 1 - Introduction: Exploring Life AIM: What are the major characteristics of life?