AP Biology

1. AP Biology Introduction: Themes in the Study of Life The Chemistry of Life Test Number 1

2. Chapter 1:Themes in the Study of Life • This chapter outlines broad themes that unify the study of biology and describe the scientific construction of biological knowledge. • A course in biology is neither a vocabulary course nor a classification exercise for the diverse forms of life. • Biology is a collection of facts and concepts structured within theories and organizing principles. • RECOGNIZING the common themes within biology will help you to structure your knowledge of this fascinating and challenging study of life.

3. Themes: • A beginning biology student can make sense of the exploding body of knowledge within biology by focusing on a few enduring themes that unify the study of biology

4. Life’s Hierarchical Order • The living world is a hierarchy, with each level of biological structure building on the level below it. Example: least to complex Atom Molecule Cell Tissue Organ Organ System Organism Species Population Community Ecosystem Biosphere • Can YOU do it?

5. Life’s Hierarchical Order • Each Level of biological structure has emergent properties. • An emergent property is a property which a collection or complex system has, but which the individual members do not have. • Interactions among components at each level of organization lead to the emergence of novel properties in the next level: The whole is greater than the sum of the parts. • The properties of live include: order, reproduction, growth, development directed by heritable programs, energy utilization, responsiveness to the environment, homeostasis and evolutionary adaptation.

6. Life’s Hierarchical Order • Cells are an organism’s basic units of structure and function. • 1665 Hooke • 1839 Schleiden and Schwann • Electron Microscope • Prokaryotes vs. eukaryotes

7. Life’s Hierarchical Order • The continuity of life is based on heritable information in the form of DNA. • Biological instructions for development and functioning are encoded within four kinds of nucleotides in DNA • A precise mechanism for replicating DNA is essential for cell division. • All forms of life use essentially the same genetic code.

8. Life’s Hierarchical Order • Structure and Function are correlated at all levels of biological organization. • The form of a biological structure gives information about its function, and the study of function provides insight into structural organization. • Form fits function is illustrated at all levels of biological organization.

9. Life’s Hierarchical Order • Organisms are open systems that interact continuously with their environments. • Organisms affect and are affected by the physical and biological environments they interact with. • Can YOU give an example???

10. Life’s Hierarchical Order • Regulatory mechanisms ensure a dynamic balance in living systems. • Enzymes are organic catalysts produced by the cell that speed up chemical reactions. • Precise regulation of its enzymes allows a cell to respond to changing conditions or needs. • Organisms maintain homeostasis through positive and negative feedback systems.

11. Evolution, Unity and Diversity • Diversity and unity are the dual faces of life on Earth • Taxonomy is the branch of biology that names organisms and classifies species into hierarchical groups. • Domains, Kingdoms, Phylum (Division), • Within life’s diversity, living forms share a universal genetic code and similarities in cell structure.

12. Evolution, Unity and Diversity • Evolution is the CORE THEME in BIOLOGY! • Evolution connects all of life by common ancestry • 1859 Charles Darwin • Natural Selection • Differential reproduction

13. Science as a Process • Testable hypotheses are the hallmarks of the scientific process. • The scientific process is based on hypothetico-deductive thinking. • Deductive reasoning proceeds from the general to the specific; from general hypothesis to specific predictions of results. • Hypotheses have important aspects: possible causes or explanations, reflect past experiences with similar situations, must be testable, can be rejected but not proven.

14. Science as a Process • Science and technology are functions of society. • Science and technology are interwoven as the information gathered by science is used in the development of goods and services, and as technological advances are used to extend scientific knowledge.

15. Science as a Process • Biology is a multidisciplinary adventure. • Biology incorporates concepts from chemistry, physics, and math.

16. The Chemical Context of Life • Chapter two considers the basic principles of chemistry that explain the behavior of atoms and molecules and that form the basis for our modern understanding of biology. • Emergent properties are associated with each new level of structural organization as the subatomic particles (protons, neutrons, electrons,) are organized into atoms, and atoms are combined by covalent or ionic bonds into molecules.

17. Interactive Questions • What is the difference between mass and weight? • How do the terms mass, volume, matter and weight relate to each other?

18. Life requires about 25 chemical elements. • Carbon, Hydrogen, Oxygen, and Nitrogen make up 96% of living matter. • The remaining 4% is composed of seven elements: Calcium, Phosphorus, Potassium, Sulfur, Sodium, Chlorine, and Magnesium. Do you know the symbols for each of these elements? • Some elements like iron and iodine may be required in very minute quantities and are called TRACE ELEMENTS.

19. Subatomic Particles • List and describe the subatomic particles with respect to charge, mass, and location within the atom. • How does the word Dalton relate to atomic mass? A Dalton is the measurement unit for atomic mass. AMU or atomic mass unit is also used to measure atomic mass.

20. Atomic Number, Atomic Weight • A = Atomic Number • Z = Mass Number • W = Atomic Weight • For each of the following, give the number of protons, neutrons, electrons for the following atom and ion • Mg when Z = 25 • S when A = 16, Z = 34, number of electrons 18

21. Interactive Question • The difference between the mass number and the atomic number of an atom is equal to the number of ________________________ . • An atom of phosphorus, P, contains ____ protons, ____ electrons, and _____ neutrons. The atomic weight of phosphorus is _______ .

22. Valence Electrons • What are the valences of the following common elements? • Hydrogen • Oxygen • Carbon • Nitrogen How do you find out valences using the periodic table? How do you use valences to determine correct structures of molecules?

23. Periodic Table

24. Bonding Between Molecules • Weak forces of attraction are used as interactions between molecules and are involved in many biological signals and processes. • WEAK BONDS within large molecules such as PROTEINS help to create the three-dimensional shape and resulting activity of these molecules. • HYDROGEN BONDS: When a hydrogen atom is covalently bonded with an electronegative atom (O, N, or F) there will be a force of attraction between the hydrogen of one molecule and the electronegative atom of the other molecule. • Van der Waals Interactions: Momentary uneven electron distributions produce changing positive and negative regions that create these weak attractions.

25. Electronegativity, Polar, Nonpolar • Define and state the relationship between the terms above.

26. Chemical Reactions • Chemical equilibrium may be reached when the forward and reverse reactions proceed at the same rate, and the relative concentrations of reactants and products no longer change.

27. This PPT. • Use this PPT as a review of your reading. • Before taking Test Number 1 make sure that you perform the practice quiz at the end of chapter 1 and chapter 2. • READ chapter 1 and chapter 2. • Look over the Chapter 1 and Chapter 2 Summaries.